U.S. Department of Agriculture (USDA) Natural Resources Conservation Service (NRCS) helped Terry and Gail Small with their Animal Mortality Facility, In-Vessel Composter that disposes of daily poultry mortality; a process that produces a pathogen free compost product that can then be applied to the land according to the nutrient management plan, Hector AR, on June 26, 2019. The purpose of this composters is to reduce the impact of pollution on surface and groundwater and reduce odor. Even in the event of a power outage, the process continues in the safety of its large long horizontal plastic container. The ingredients are simple, for every bucket of chicken, in goes a bucket of wood shavings.

 

Inside, an internal drum with spiral blades rotates very slowly mixing, moving and aerating the mixture. The natural process brings the interior temperature to120-125 degrees Fahrenheit. At the end, the compost is slowly expelled -- ready to use. The producer is then able to use it in fields or sell it.

  

The Smalls work with NRCS District Conservationist Joe Tapp and Agricultural Engineer Britt Hill on their conservation plan that includes this mortality facility.

 

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NRCS has a proud history of supporting America’s farmers, ranchers, and forest landowners. For more than 80 years, we have helped people make investments in their operations and local communities to keep working lands working, boost rural economies, increase the competitiveness of American agriculture, and improve the quality of our air, water, soil, and habitat.

 

As the USDA’s primary private lands conservation agency, we generate, manage, and share the data, technology, and standards that enable partners and policymakers to make decisions informed by objective, reliable science.

 

And through one-on-one, personalized advice, we work voluntarily with producers and communities to find the best solutions to meet their unique conservation and business goals. By doing so, we help ensure the health of our natural resources and the long-term sustainability of American agriculture.

  

Farm Production and Conservation (FPAC) is the Department’s focal point for the nation’s farmers and ranchers and other stewards of private agricultural lands and non-industrial private forest lands. FPAC agencies implement programs designed to mitigate the significant risks of farming through crop insurance services, conservation programs and technical assistance, and commodity, lending, and disaster programs.

 

The agencies and service supporting FPAC are Farm Service Agency (FSA), NRCS, and Risk Management Agency (RMA).

  

For more information please see www.usda.gov.

 

USDA Photo by Lance Cheung.

   

A fungus (pl.: fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as one of the traditional eukaryotic kingdoms, along with Animalia, Plantae and either Protista or Protozoa and Chromista.

 

A characteristic that places fungi in a different kingdom from plants, bacteria, and some protists is chitin in their cell walls. Fungi, like animals, are heterotrophs; they acquire their food by absorbing dissolved molecules, typically by secreting digestive enzymes into their environment. Fungi do not photosynthesize. Growth is their means of mobility, except for spores (a few of which are flagellated), which may travel through the air or water. Fungi are the principal decomposers in ecological systems. These and other differences place fungi in a single group of related organisms, named the Eumycota (true fungi or Eumycetes), that share a common ancestor (i.e. they form a monophyletic group), an interpretation that is also strongly supported by molecular phylogenetics. This fungal group is distinct from the structurally similar myxomycetes (slime molds) and oomycetes (water molds). The discipline of biology devoted to the study of fungi is known as mycology (from the Greek μύκης mykes, mushroom). In the past mycology was regarded as a branch of botany, although it is now known that fungi are genetically more closely related to animals than to plants.

 

Abundant worldwide, most fungi are inconspicuous because of the small size of their structures, and their cryptic lifestyles in soil or on dead matter. Fungi include symbionts of plants, animals, or other fungi and also parasites. They may become noticeable when fruiting, either as mushrooms or as molds. Fungi perform an essential role in the decomposition of organic matter and have fundamental roles in nutrient cycling and exchange in the environment. They have long been used as a direct source of human food, in the form of mushrooms and truffles; as a leavening agent for bread; and in the fermentation of various food products, such as wine, beer, and soy sauce. Since the 1940s, fungi have been used for the production of antibiotics, and, more recently, various enzymes produced by fungi are used industrially and in detergents. Fungi are also used as biological pesticides to control weeds, plant diseases, and insect pests. Many species produce bioactive compounds called mycotoxins, such as alkaloids and polyketides, that are toxic to animals, including humans. The fruiting structures of a few species contain psychotropic compounds and are consumed recreationally or in traditional spiritual ceremonies. Fungi can break down manufactured materials and buildings, and become significant pathogens of humans and other animals. Losses of crops due to fungal diseases (e.g., rice blast disease) or food spoilage can have a large impact on human food supplies and local economies.

 

The fungus kingdom encompasses an enormous diversity of taxa with varied ecologies, life cycle strategies, and morphologies ranging from unicellular aquatic chytrids to large mushrooms. However, little is known of the true biodiversity of the fungus kingdom, which has been estimated at 2.2 million to 3.8 million species. Of these, only about 148,000 have been described, with over 8,000 species known to be detrimental to plants and at least 300 that can be pathogenic to humans. Ever since the pioneering 18th and 19th century taxonomical works of Carl Linnaeus, Christiaan Hendrik Persoon, and Elias Magnus Fries, fungi have been classified according to their morphology (e.g., characteristics such as spore color or microscopic features) or physiology. Advances in molecular genetics have opened the way for DNA analysis to be incorporated into taxonomy, which has sometimes challenged the historical groupings based on morphology and other traits. Phylogenetic studies published in the first decade of the 21st century have helped reshape the classification within the fungi kingdom, which is divided into one subkingdom, seven phyla, and ten subphyla.

 

Etymology

The English word fungus is directly adopted from the Latin fungus (mushroom), used in the writings of Horace and Pliny. This in turn is derived from the Greek word sphongos (σφόγγος 'sponge'), which refers to the macroscopic structures and morphology of mushrooms and molds; the root is also used in other languages, such as the German Schwamm ('sponge') and Schimmel ('mold').

 

The word mycology is derived from the Greek mykes (μύκης 'mushroom') and logos (λόγος 'discourse'). It denotes the scientific study of fungi. The Latin adjectival form of "mycology" (mycologicæ) appeared as early as 1796 in a book on the subject by Christiaan Hendrik Persoon. The word appeared in English as early as 1824 in a book by Robert Kaye Greville. In 1836 the English naturalist Miles Joseph Berkeley's publication The English Flora of Sir James Edward Smith, Vol. 5. also refers to mycology as the study of fungi.

 

A group of all the fungi present in a particular region is known as mycobiota (plural noun, no singular). The term mycota is often used for this purpose, but many authors use it as a synonym of Fungi. The word funga has been proposed as a less ambiguous term morphologically similar to fauna and flora. The Species Survival Commission (SSC) of the International Union for Conservation of Nature (IUCN) in August 2021 asked that the phrase fauna and flora be replaced by fauna, flora, and funga.

 

Characteristics

 

Fungal hyphae cells

Hyphal wall

Septum

Mitochondrion

Vacuole

Ergosterol crystal

Ribosome

Nucleus

Endoplasmic reticulum

Lipid body

Plasma membrane

Spitzenkörper

Golgi apparatus

 

Fungal cell cycle showing Dikaryons typical of Higher Fungi

Before the introduction of molecular methods for phylogenetic analysis, taxonomists considered fungi to be members of the plant kingdom because of similarities in lifestyle: both fungi and plants are mainly immobile, and have similarities in general morphology and growth habitat. Although inaccurate, the common misconception that fungi are plants persists among the general public due to their historical classification, as well as several similarities. Like plants, fungi often grow in soil and, in the case of mushrooms, form conspicuous fruit bodies, which sometimes resemble plants such as mosses. The fungi are now considered a separate kingdom, distinct from both plants and animals, from which they appear to have diverged around one billion years ago (around the start of the Neoproterozoic Era). Some morphological, biochemical, and genetic features are shared with other organisms, while others are unique to the fungi, clearly separating them from the other kingdoms:

 

With other eukaryotes: Fungal cells contain membrane-bound nuclei with chromosomes that contain DNA with noncoding regions called introns and coding regions called exons. Fungi have membrane-bound cytoplasmic organelles such as mitochondria, sterol-containing membranes, and ribosomes of the 80S type. They have a characteristic range of soluble carbohydrates and storage compounds, including sugar alcohols (e.g., mannitol), disaccharides, (e.g., trehalose), and polysaccharides (e.g., glycogen, which is also found in animals).

With animals: Fungi lack chloroplasts and are heterotrophic organisms and so require preformed organic compounds as energy sources.

With plants: Fungi have a cell wall and vacuoles. They reproduce by both sexual and asexual means, and like basal plant groups (such as ferns and mosses) produce spores. Similar to mosses and algae, fungi typically have haploid nuclei.

With euglenoids and bacteria: Higher fungi, euglenoids, and some bacteria produce the amino acid L-lysine in specific biosynthesis steps, called the α-aminoadipate pathway.

The cells of most fungi grow as tubular, elongated, and thread-like (filamentous) structures called hyphae, which may contain multiple nuclei and extend by growing at their tips. Each tip contains a set of aggregated vesicles—cellular structures consisting of proteins, lipids, and other organic molecules—called the Spitzenkörper. Both fungi and oomycetes grow as filamentous hyphal cells. In contrast, similar-looking organisms, such as filamentous green algae, grow by repeated cell division within a chain of cells. There are also single-celled fungi (yeasts) that do not form hyphae, and some fungi have both hyphal and yeast forms.

In common with some plant and animal species, more than one hundred fungal species display bioluminescence.

Unique features:

 

Some species grow as unicellular yeasts that reproduce by budding or fission. Dimorphic fungi can switch between a yeast phase and a hyphal phase in response to environmental conditions.

The fungal cell wall is made of a chitin-glucan complex; while glucans are also found in plants and chitin in the exoskeleton of arthropods, fungi are the only organisms that combine these two structural molecules in their cell wall. Unlike those of plants and oomycetes, fungal cell walls do not contain cellulose.

A whitish fan or funnel-shaped mushroom growing at the base of a tree.

Omphalotus nidiformis, a bioluminescent mushroom

Most fungi lack an efficient system for the long-distance transport of water and nutrients, such as the xylem and phloem in many plants. To overcome this limitation, some fungi, such as Armillaria, form rhizomorphs, which resemble and perform functions similar to the roots of plants. As eukaryotes, fungi possess a biosynthetic pathway for producing terpenes that uses mevalonic acid and pyrophosphate as chemical building blocks. Plants and some other organisms have an additional terpene biosynthesis pathway in their chloroplasts, a structure that fungi and animals do not have. Fungi produce several secondary metabolites that are similar or identical in structure to those made by plants. Many of the plant and fungal enzymes that make these compounds differ from each other in sequence and other characteristics, which indicates separate origins and convergent evolution of these enzymes in the fungi and plants.

 

Diversity

Fungi have a worldwide distribution, and grow in a wide range of habitats, including extreme environments such as deserts or areas with high salt concentrations or ionizing radiation, as well as in deep sea sediments. Some can survive the intense UV and cosmic radiation encountered during space travel. Most grow in terrestrial environments, though several species live partly or solely in aquatic habitats, such as the chytrid fungi Batrachochytrium dendrobatidis and B. salamandrivorans, parasites that have been responsible for a worldwide decline in amphibian populations. These organisms spend part of their life cycle as a motile zoospore, enabling them to propel itself through water and enter their amphibian host. Other examples of aquatic fungi include those living in hydrothermal areas of the ocean.

 

As of 2020, around 148,000 species of fungi have been described by taxonomists, but the global biodiversity of the fungus kingdom is not fully understood. A 2017 estimate suggests there may be between 2.2 and 3.8 million species The number of new fungi species discovered yearly has increased from 1,000 to 1,500 per year about 10 years ago, to about 2000 with a peak of more than 2,500 species in 2016. In the year 2019, 1882 new species of fungi were described, and it was estimated that more than 90% of fungi remain unknown The following year, 2905 new species were described—the highest annual record of new fungus names. In mycology, species have historically been distinguished by a variety of methods and concepts. Classification based on morphological characteristics, such as the size and shape of spores or fruiting structures, has traditionally dominated fungal taxonomy. Species may also be distinguished by their biochemical and physiological characteristics, such as their ability to metabolize certain biochemicals, or their reaction to chemical tests. The biological species concept discriminates species based on their ability to mate. The application of molecular tools, such as DNA sequencing and phylogenetic analysis, to study diversity has greatly enhanced the resolution and added robustness to estimates of genetic diversity within various taxonomic groups.

 

Mycology

Mycology is the branch of biology concerned with the systematic study of fungi, including their genetic and biochemical properties, their taxonomy, and their use to humans as a source of medicine, food, and psychotropic substances consumed for religious purposes, as well as their dangers, such as poisoning or infection. The field of phytopathology, the study of plant diseases, is closely related because many plant pathogens are fungi.

 

The use of fungi by humans dates back to prehistory; Ötzi the Iceman, a well-preserved mummy of a 5,300-year-old Neolithic man found frozen in the Austrian Alps, carried two species of polypore mushrooms that may have been used as tinder (Fomes fomentarius), or for medicinal purposes (Piptoporus betulinus). Ancient peoples have used fungi as food sources—often unknowingly—for millennia, in the preparation of leavened bread and fermented juices. Some of the oldest written records contain references to the destruction of crops that were probably caused by pathogenic fungi.

 

History

Mycology became a systematic science after the development of the microscope in the 17th century. Although fungal spores were first observed by Giambattista della Porta in 1588, the seminal work in the development of mycology is considered to be the publication of Pier Antonio Micheli's 1729 work Nova plantarum genera. Micheli not only observed spores but also showed that, under the proper conditions, they could be induced into growing into the same species of fungi from which they originated. Extending the use of the binomial system of nomenclature introduced by Carl Linnaeus in his Species plantarum (1753), the Dutch Christiaan Hendrik Persoon (1761–1836) established the first classification of mushrooms with such skill as to be considered a founder of modern mycology. Later, Elias Magnus Fries (1794–1878) further elaborated the classification of fungi, using spore color and microscopic characteristics, methods still used by taxonomists today. Other notable early contributors to mycology in the 17th–19th and early 20th centuries include Miles Joseph Berkeley, August Carl Joseph Corda, Anton de Bary, the brothers Louis René and Charles Tulasne, Arthur H. R. Buller, Curtis G. Lloyd, and Pier Andrea Saccardo. In the 20th and 21st centuries, advances in biochemistry, genetics, molecular biology, biotechnology, DNA sequencing and phylogenetic analysis has provided new insights into fungal relationships and biodiversity, and has challenged traditional morphology-based groupings in fungal taxonomy.

 

Morphology

Microscopic structures

Monochrome micrograph showing Penicillium hyphae as long, transparent, tube-like structures a few micrometres across. Conidiophores branch out laterally from the hyphae, terminating in bundles of phialides on which spherical condidiophores are arranged like beads on a string. Septa are faintly visible as dark lines crossing the hyphae.

An environmental isolate of Penicillium

Hypha

Conidiophore

Phialide

Conidia

Septa

Most fungi grow as hyphae, which are cylindrical, thread-like structures 2–10 µm in diameter and up to several centimeters in length. Hyphae grow at their tips (apices); new hyphae are typically formed by emergence of new tips along existing hyphae by a process called branching, or occasionally growing hyphal tips fork, giving rise to two parallel-growing hyphae. Hyphae also sometimes fuse when they come into contact, a process called hyphal fusion (or anastomosis). These growth processes lead to the development of a mycelium, an interconnected network of hyphae. Hyphae can be either septate or coenocytic. Septate hyphae are divided into compartments separated by cross walls (internal cell walls, called septa, that are formed at right angles to the cell wall giving the hypha its shape), with each compartment containing one or more nuclei; coenocytic hyphae are not compartmentalized. Septa have pores that allow cytoplasm, organelles, and sometimes nuclei to pass through; an example is the dolipore septum in fungi of the phylum Basidiomycota. Coenocytic hyphae are in essence multinucleate supercells.

 

Many species have developed specialized hyphal structures for nutrient uptake from living hosts; examples include haustoria in plant-parasitic species of most fungal phyla,[63] and arbuscules of several mycorrhizal fungi, which penetrate into the host cells to consume nutrients.

 

Although fungi are opisthokonts—a grouping of evolutionarily related organisms broadly characterized by a single posterior flagellum—all phyla except for the chytrids have lost their posterior flagella. Fungi are unusual among the eukaryotes in having a cell wall that, in addition to glucans (e.g., β-1,3-glucan) and other typical components, also contains the biopolymer chitin.

 

Macroscopic structures

Fungal mycelia can become visible to the naked eye, for example, on various surfaces and substrates, such as damp walls and spoiled food, where they are commonly called molds. Mycelia grown on solid agar media in laboratory petri dishes are usually referred to as colonies. These colonies can exhibit growth shapes and colors (due to spores or pigmentation) that can be used as diagnostic features in the identification of species or groups. Some individual fungal colonies can reach extraordinary dimensions and ages as in the case of a clonal colony of Armillaria solidipes, which extends over an area of more than 900 ha (3.5 square miles), with an estimated age of nearly 9,000 years.

 

The apothecium—a specialized structure important in sexual reproduction in the ascomycetes—is a cup-shaped fruit body that is often macroscopic and holds the hymenium, a layer of tissue containing the spore-bearing cells. The fruit bodies of the basidiomycetes (basidiocarps) and some ascomycetes can sometimes grow very large, and many are well known as mushrooms.

 

Growth and physiology

Time-lapse photography sequence of a peach becoming progressively discolored and disfigured

Mold growth covering a decaying peach. The frames were taken approximately 12 hours apart over a period of six days.

The growth of fungi as hyphae on or in solid substrates or as single cells in aquatic environments is adapted for the efficient extraction of nutrients, because these growth forms have high surface area to volume ratios. Hyphae are specifically adapted for growth on solid surfaces, and to invade substrates and tissues. They can exert large penetrative mechanical forces; for example, many plant pathogens, including Magnaporthe grisea, form a structure called an appressorium that evolved to puncture plant tissues.[71] The pressure generated by the appressorium, directed against the plant epidermis, can exceed 8 megapascals (1,200 psi).[71] The filamentous fungus Paecilomyces lilacinus uses a similar structure to penetrate the eggs of nematodes.

 

The mechanical pressure exerted by the appressorium is generated from physiological processes that increase intracellular turgor by producing osmolytes such as glycerol. Adaptations such as these are complemented by hydrolytic enzymes secreted into the environment to digest large organic molecules—such as polysaccharides, proteins, and lipids—into smaller molecules that may then be absorbed as nutrients. The vast majority of filamentous fungi grow in a polar fashion (extending in one direction) by elongation at the tip (apex) of the hypha. Other forms of fungal growth include intercalary extension (longitudinal expansion of hyphal compartments that are below the apex) as in the case of some endophytic fungi, or growth by volume expansion during the development of mushroom stipes and other large organs. Growth of fungi as multicellular structures consisting of somatic and reproductive cells—a feature independently evolved in animals and plants—has several functions, including the development of fruit bodies for dissemination of sexual spores (see above) and biofilms for substrate colonization and intercellular communication.

 

Fungi are traditionally considered heterotrophs, organisms that rely solely on carbon fixed by other organisms for metabolism. Fungi have evolved a high degree of metabolic versatility that allows them to use a diverse range of organic substrates for growth, including simple compounds such as nitrate, ammonia, acetate, or ethanol. In some species the pigment melanin may play a role in extracting energy from ionizing radiation, such as gamma radiation. This form of "radiotrophic" growth has been described for only a few species, the effects on growth rates are small, and the underlying biophysical and biochemical processes are not well known. This process might bear similarity to CO2 fixation via visible light, but instead uses ionizing radiation as a source of energy.

 

Reproduction

Two thickly stemmed brownish mushrooms with scales on the upper surface, growing out of a tree trunk

Polyporus squamosus

Fungal reproduction is complex, reflecting the differences in lifestyles and genetic makeup within this diverse kingdom of organisms. It is estimated that a third of all fungi reproduce using more than one method of propagation; for example, reproduction may occur in two well-differentiated stages within the life cycle of a species, the teleomorph (sexual reproduction) and the anamorph (asexual reproduction). Environmental conditions trigger genetically determined developmental states that lead to the creation of specialized structures for sexual or asexual reproduction. These structures aid reproduction by efficiently dispersing spores or spore-containing propagules.

 

Asexual reproduction

Asexual reproduction occurs via vegetative spores (conidia) or through mycelial fragmentation. Mycelial fragmentation occurs when a fungal mycelium separates into pieces, and each component grows into a separate mycelium. Mycelial fragmentation and vegetative spores maintain clonal populations adapted to a specific niche, and allow more rapid dispersal than sexual reproduction. The "Fungi imperfecti" (fungi lacking the perfect or sexual stage) or Deuteromycota comprise all the species that lack an observable sexual cycle. Deuteromycota (alternatively known as Deuteromycetes, conidial fungi, or mitosporic fungi) is not an accepted taxonomic clade and is now taken to mean simply fungi that lack a known sexual stage.

 

Sexual reproduction

See also: Mating in fungi and Sexual selection in fungi

Sexual reproduction with meiosis has been directly observed in all fungal phyla except Glomeromycota (genetic analysis suggests meiosis in Glomeromycota as well). It differs in many aspects from sexual reproduction in animals or plants. Differences also exist between fungal groups and can be used to discriminate species by morphological differences in sexual structures and reproductive strategies. Mating experiments between fungal isolates may identify species on the basis of biological species concepts. The major fungal groupings have initially been delineated based on the morphology of their sexual structures and spores; for example, the spore-containing structures, asci and basidia, can be used in the identification of ascomycetes and basidiomycetes, respectively. Fungi employ two mating systems: heterothallic species allow mating only between individuals of the opposite mating type, whereas homothallic species can mate, and sexually reproduce, with any other individual or itself.

 

Most fungi have both a haploid and a diploid stage in their life cycles. In sexually reproducing fungi, compatible individuals may combine by fusing their hyphae together into an interconnected network; this process, anastomosis, is required for the initiation of the sexual cycle. Many ascomycetes and basidiomycetes go through a dikaryotic stage, in which the nuclei inherited from the two parents do not combine immediately after cell fusion, but remain separate in the hyphal cells (see heterokaryosis).

 

In ascomycetes, dikaryotic hyphae of the hymenium (the spore-bearing tissue layer) form a characteristic hook (crozier) at the hyphal septum. During cell division, the formation of the hook ensures proper distribution of the newly divided nuclei into the apical and basal hyphal compartments. An ascus (plural asci) is then formed, in which karyogamy (nuclear fusion) occurs. Asci are embedded in an ascocarp, or fruiting body. Karyogamy in the asci is followed immediately by meiosis and the production of ascospores. After dispersal, the ascospores may germinate and form a new haploid mycelium.

 

Sexual reproduction in basidiomycetes is similar to that of the ascomycetes. Compatible haploid hyphae fuse to produce a dikaryotic mycelium. However, the dikaryotic phase is more extensive in the basidiomycetes, often also present in the vegetatively growing mycelium. A specialized anatomical structure, called a clamp connection, is formed at each hyphal septum. As with the structurally similar hook in the ascomycetes, the clamp connection in the basidiomycetes is required for controlled transfer of nuclei during cell division, to maintain the dikaryotic stage with two genetically different nuclei in each hyphal compartment. A basidiocarp is formed in which club-like structures known as basidia generate haploid basidiospores after karyogamy and meiosis. The most commonly known basidiocarps are mushrooms, but they may also take other forms (see Morphology section).

 

In fungi formerly classified as Zygomycota, haploid hyphae of two individuals fuse, forming a gametangium, a specialized cell structure that becomes a fertile gamete-producing cell. The gametangium develops into a zygospore, a thick-walled spore formed by the union of gametes. When the zygospore germinates, it undergoes meiosis, generating new haploid hyphae, which may then form asexual sporangiospores. These sporangiospores allow the fungus to rapidly disperse and germinate into new genetically identical haploid fungal mycelia.

 

Spore dispersal

The spores of most of the researched species of fungi are transported by wind. Such species often produce dry or hydrophobic spores that do not absorb water and are readily scattered by raindrops, for example. In other species, both asexual and sexual spores or sporangiospores are often actively dispersed by forcible ejection from their reproductive structures. This ejection ensures exit of the spores from the reproductive structures as well as traveling through the air over long distances.

 

Specialized mechanical and physiological mechanisms, as well as spore surface structures (such as hydrophobins), enable efficient spore ejection. For example, the structure of the spore-bearing cells in some ascomycete species is such that the buildup of substances affecting cell volume and fluid balance enables the explosive discharge of spores into the air. The forcible discharge of single spores termed ballistospores involves formation of a small drop of water (Buller's drop), which upon contact with the spore leads to its projectile release with an initial acceleration of more than 10,000 g; the net result is that the spore is ejected 0.01–0.02 cm, sufficient distance for it to fall through the gills or pores into the air below. Other fungi, like the puffballs, rely on alternative mechanisms for spore release, such as external mechanical forces. The hydnoid fungi (tooth fungi) produce spores on pendant, tooth-like or spine-like projections. The bird's nest fungi use the force of falling water drops to liberate the spores from cup-shaped fruiting bodies. Another strategy is seen in the stinkhorns, a group of fungi with lively colors and putrid odor that attract insects to disperse their spores.

 

Homothallism

In homothallic sexual reproduction, two haploid nuclei derived from the same individual fuse to form a zygote that can then undergo meiosis. Homothallic fungi include species with an Aspergillus-like asexual stage (anamorphs) occurring in numerous different genera, several species of the ascomycete genus Cochliobolus, and the ascomycete Pneumocystis jirovecii. The earliest mode of sexual reproduction among eukaryotes was likely homothallism, that is, self-fertile unisexual reproduction.

 

Other sexual processes

Besides regular sexual reproduction with meiosis, certain fungi, such as those in the genera Penicillium and Aspergillus, may exchange genetic material via parasexual processes, initiated by anastomosis between hyphae and plasmogamy of fungal cells. The frequency and relative importance of parasexual events is unclear and may be lower than other sexual processes. It is known to play a role in intraspecific hybridization and is likely required for hybridization between species, which has been associated with major events in fungal evolution.

 

Evolution

In contrast to plants and animals, the early fossil record of the fungi is meager. Factors that likely contribute to the under-representation of fungal species among fossils include the nature of fungal fruiting bodies, which are soft, fleshy, and easily degradable tissues and the microscopic dimensions of most fungal structures, which therefore are not readily evident. Fungal fossils are difficult to distinguish from those of other microbes, and are most easily identified when they resemble extant fungi. Often recovered from a permineralized plant or animal host, these samples are typically studied by making thin-section preparations that can be examined with light microscopy or transmission electron microscopy. Researchers study compression fossils by dissolving the surrounding matrix with acid and then using light or scanning electron microscopy to examine surface details.

 

The earliest fossils possessing features typical of fungi date to the Paleoproterozoic era, some 2,400 million years ago (Ma); these multicellular benthic organisms had filamentous structures capable of anastomosis. Other studies (2009) estimate the arrival of fungal organisms at about 760–1060 Ma on the basis of comparisons of the rate of evolution in closely related groups. The oldest fossilizied mycelium to be identified from its molecular composition is between 715 and 810 million years old. For much of the Paleozoic Era (542–251 Ma), the fungi appear to have been aquatic and consisted of organisms similar to the extant chytrids in having flagellum-bearing spores. The evolutionary adaptation from an aquatic to a terrestrial lifestyle necessitated a diversification of ecological strategies for obtaining nutrients, including parasitism, saprobism, and the development of mutualistic relationships such as mycorrhiza and lichenization. Studies suggest that the ancestral ecological state of the Ascomycota was saprobism, and that independent lichenization events have occurred multiple times.

 

In May 2019, scientists reported the discovery of a fossilized fungus, named Ourasphaira giraldae, in the Canadian Arctic, that may have grown on land a billion years ago, well before plants were living on land. Pyritized fungus-like microfossils preserved in the basal Ediacaran Doushantuo Formation (~635 Ma) have been reported in South China. Earlier, it had been presumed that the fungi colonized the land during the Cambrian (542–488.3 Ma), also long before land plants. Fossilized hyphae and spores recovered from the Ordovician of Wisconsin (460 Ma) resemble modern-day Glomerales, and existed at a time when the land flora likely consisted of only non-vascular bryophyte-like plants. Prototaxites, which was probably a fungus or lichen, would have been the tallest organism of the late Silurian and early Devonian. Fungal fossils do not become common and uncontroversial until the early Devonian (416–359.2 Ma), when they occur abundantly in the Rhynie chert, mostly as Zygomycota and Chytridiomycota. At about this same time, approximately 400 Ma, the Ascomycota and Basidiomycota diverged, and all modern classes of fungi were present by the Late Carboniferous (Pennsylvanian, 318.1–299 Ma).

 

Lichens formed a component of the early terrestrial ecosystems, and the estimated age of the oldest terrestrial lichen fossil is 415 Ma; this date roughly corresponds to the age of the oldest known sporocarp fossil, a Paleopyrenomycites species found in the Rhynie Chert. The oldest fossil with microscopic features resembling modern-day basidiomycetes is Palaeoancistrus, found permineralized with a fern from the Pennsylvanian. Rare in the fossil record are the Homobasidiomycetes (a taxon roughly equivalent to the mushroom-producing species of the Agaricomycetes). Two amber-preserved specimens provide evidence that the earliest known mushroom-forming fungi (the extinct species Archaeomarasmius leggetti) appeared during the late Cretaceous, 90 Ma.

 

Some time after the Permian–Triassic extinction event (251.4 Ma), a fungal spike (originally thought to be an extraordinary abundance of fungal spores in sediments) formed, suggesting that fungi were the dominant life form at this time, representing nearly 100% of the available fossil record for this period. However, the relative proportion of fungal spores relative to spores formed by algal species is difficult to assess, the spike did not appear worldwide, and in many places it did not fall on the Permian–Triassic boundary.

 

Sixty-five million years ago, immediately after the Cretaceous–Paleogene extinction event that famously killed off most dinosaurs, there was a dramatic increase in evidence of fungi; apparently the death of most plant and animal species led to a huge fungal bloom like "a massive compost heap".

 

Taxonomy

Although commonly included in botany curricula and textbooks, fungi are more closely related to animals than to plants and are placed with the animals in the monophyletic group of opisthokonts. Analyses using molecular phylogenetics support a monophyletic origin of fungi. The taxonomy of fungi is in a state of constant flux, especially due to research based on DNA comparisons. These current phylogenetic analyses often overturn classifications based on older and sometimes less discriminative methods based on morphological features and biological species concepts obtained from experimental matings.

 

There is no unique generally accepted system at the higher taxonomic levels and there are frequent name changes at every level, from species upwards. Efforts among researchers are now underway to establish and encourage usage of a unified and more consistent nomenclature. Until relatively recent (2012) changes to the International Code of Nomenclature for algae, fungi and plants, fungal species could also have multiple scientific names depending on their life cycle and mode (sexual or asexual) of reproduction. Web sites such as Index Fungorum and MycoBank are officially recognized nomenclatural repositories and list current names of fungal species (with cross-references to older synonyms).

 

The 2007 classification of Kingdom Fungi is the result of a large-scale collaborative research effort involving dozens of mycologists and other scientists working on fungal taxonomy. It recognizes seven phyla, two of which—the Ascomycota and the Basidiomycota—are contained within a branch representing subkingdom Dikarya, the most species rich and familiar group, including all the mushrooms, most food-spoilage molds, most plant pathogenic fungi, and the beer, wine, and bread yeasts. The accompanying cladogram depicts the major fungal taxa and their relationship to opisthokont and unikont organisms, based on the work of Philippe Silar, "The Mycota: A Comprehensive Treatise on Fungi as Experimental Systems for Basic and Applied Research" and Tedersoo et al. 2018. The lengths of the branches are not proportional to evolutionary distances.

 

The major phyla (sometimes called divisions) of fungi have been classified mainly on the basis of characteristics of their sexual reproductive structures. As of 2019, nine major lineages have been identified: Opisthosporidia, Chytridiomycota, Neocallimastigomycota, Blastocladiomycota, Zoopagomycotina, Mucoromycota, Glomeromycota, Ascomycota and Basidiomycota.

 

Phylogenetic analysis has demonstrated that the Microsporidia, unicellular parasites of animals and protists, are fairly recent and highly derived endobiotic fungi (living within the tissue of another species). Previously considered to be "primitive" protozoa, they are now thought to be either a basal branch of the Fungi, or a sister group–each other's closest evolutionary relative.

 

The Chytridiomycota are commonly known as chytrids. These fungi are distributed worldwide. Chytrids and their close relatives Neocallimastigomycota and Blastocladiomycota (below) are the only fungi with active motility, producing zoospores that are capable of active movement through aqueous phases with a single flagellum, leading early taxonomists to classify them as protists. Molecular phylogenies, inferred from rRNA sequences in ribosomes, suggest that the Chytrids are a basal group divergent from the other fungal phyla, consisting of four major clades with suggestive evidence for paraphyly or possibly polyphyly.

 

The Blastocladiomycota were previously considered a taxonomic clade within the Chytridiomycota. Molecular data and ultrastructural characteristics, however, place the Blastocladiomycota as a sister clade to the Zygomycota, Glomeromycota, and Dikarya (Ascomycota and Basidiomycota). The blastocladiomycetes are saprotrophs, feeding on decomposing organic matter, and they are parasites of all eukaryotic groups. Unlike their close relatives, the chytrids, most of which exhibit zygotic meiosis, the blastocladiomycetes undergo sporic meiosis.

 

The Neocallimastigomycota were earlier placed in the phylum Chytridiomycota. Members of this small phylum are anaerobic organisms, living in the digestive system of larger herbivorous mammals and in other terrestrial and aquatic environments enriched in cellulose (e.g., domestic waste landfill sites). They lack mitochondria but contain hydrogenosomes of mitochondrial origin. As in the related chrytrids, neocallimastigomycetes form zoospores that are posteriorly uniflagellate or polyflagellate.

 

Microscopic view of a layer of translucent grayish cells, some containing small dark-color spheres

Arbuscular mycorrhiza seen under microscope. Flax root cortical cells containing paired arbuscules.

Cross-section of a cup-shaped structure showing locations of developing meiotic asci (upper edge of cup, left side, arrows pointing to two gray cells containing four and two small circles), sterile hyphae (upper edge of cup, right side, arrows pointing to white cells with a single small circle in them), and mature asci (upper edge of cup, pointing to two gray cells with eight small circles in them)

Diagram of an apothecium (the typical cup-like reproductive structure of Ascomycetes) showing sterile tissues as well as developing and mature asci.

Members of the Glomeromycota form arbuscular mycorrhizae, a form of mutualist symbiosis wherein fungal hyphae invade plant root cells and both species benefit from the resulting increased supply of nutrients. All known Glomeromycota species reproduce asexually. The symbiotic association between the Glomeromycota and plants is ancient, with evidence dating to 400 million years ago. Formerly part of the Zygomycota (commonly known as 'sugar' and 'pin' molds), the Glomeromycota were elevated to phylum status in 2001 and now replace the older phylum Zygomycota. Fungi that were placed in the Zygomycota are now being reassigned to the Glomeromycota, or the subphyla incertae sedis Mucoromycotina, Kickxellomycotina, the Zoopagomycotina and the Entomophthoromycotina. Some well-known examples of fungi formerly in the Zygomycota include black bread mold (Rhizopus stolonifer), and Pilobolus species, capable of ejecting spores several meters through the air. Medically relevant genera include Mucor, Rhizomucor, and Rhizopus.

 

The Ascomycota, commonly known as sac fungi or ascomycetes, constitute the largest taxonomic group within the Eumycota. These fungi form meiotic spores called ascospores, which are enclosed in a special sac-like structure called an ascus. This phylum includes morels, a few mushrooms and truffles, unicellular yeasts (e.g., of the genera Saccharomyces, Kluyveromyces, Pichia, and Candida), and many filamentous fungi living as saprotrophs, parasites, and mutualistic symbionts (e.g. lichens). Prominent and important genera of filamentous ascomycetes include Aspergillus, Penicillium, Fusarium, and Claviceps. Many ascomycete species have only been observed undergoing asexual reproduction (called anamorphic species), but analysis of molecular data has often been able to identify their closest teleomorphs in the Ascomycota. Because the products of meiosis are retained within the sac-like ascus, ascomycetes have been used for elucidating principles of genetics and heredity (e.g., Neurospora crassa).

 

Members of the Basidiomycota, commonly known as the club fungi or basidiomycetes, produce meiospores called basidiospores on club-like stalks called basidia. Most common mushrooms belong to this group, as well as rust and smut fungi, which are major pathogens of grains. Other important basidiomycetes include the maize pathogen Ustilago maydis, human commensal species of the genus Malassezia, and the opportunistic human pathogen, Cryptococcus neoformans.

 

Fungus-like organisms

Because of similarities in morphology and lifestyle, the slime molds (mycetozoans, plasmodiophorids, acrasids, Fonticula and labyrinthulids, now in Amoebozoa, Rhizaria, Excavata, Opisthokonta and Stramenopiles, respectively), water molds (oomycetes) and hyphochytrids (both Stramenopiles) were formerly classified in the kingdom Fungi, in groups like Mastigomycotina, Gymnomycota and Phycomycetes. The slime molds were studied also as protozoans, leading to an ambiregnal, duplicated taxonomy.

 

Unlike true fungi, the cell walls of oomycetes contain cellulose and lack chitin. Hyphochytrids have both chitin and cellulose. Slime molds lack a cell wall during the assimilative phase (except labyrinthulids, which have a wall of scales), and take in nutrients by ingestion (phagocytosis, except labyrinthulids) rather than absorption (osmotrophy, as fungi, labyrinthulids, oomycetes and hyphochytrids). Neither water molds nor slime molds are closely related to the true fungi, and, therefore, taxonomists no longer group them in the kingdom Fungi. Nonetheless, studies of the oomycetes and myxomycetes are still often included in mycology textbooks and primary research literature.

 

The Eccrinales and Amoebidiales are opisthokont protists, previously thought to be zygomycete fungi. Other groups now in Opisthokonta (e.g., Corallochytrium, Ichthyosporea) were also at given time classified as fungi. The genus Blastocystis, now in Stramenopiles, was originally classified as a yeast. Ellobiopsis, now in Alveolata, was considered a chytrid. The bacteria were also included in fungi in some classifications, as the group Schizomycetes.

 

The Rozellida clade, including the "ex-chytrid" Rozella, is a genetically disparate group known mostly from environmental DNA sequences that is a sister group to fungi. Members of the group that have been isolated lack the chitinous cell wall that is characteristic of fungi. Alternatively, Rozella can be classified as a basal fungal group.

 

The nucleariids may be the next sister group to the eumycete clade, and as such could be included in an expanded fungal kingdom. Many Actinomycetales (Actinomycetota), a group with many filamentous bacteria, were also long believed to be fungi.

 

Ecology

Although often inconspicuous, fungi occur in every environment on Earth and play very important roles in most ecosystems. Along with bacteria, fungi are the major decomposers in most terrestrial (and some aquatic) ecosystems, and therefore play a critical role in biogeochemical cycles and in many food webs. As decomposers, they play an essential role in nutrient cycling, especially as saprotrophs and symbionts, degrading organic matter to inorganic molecules, which can then re-enter anabolic metabolic pathways in plants or other organisms.

 

Symbiosis

Many fungi have important symbiotic relationships with organisms from most if not all kingdoms. These interactions can be mutualistic or antagonistic in nature, or in the case of commensal fungi are of no apparent benefit or detriment to the host.

 

With plants

Mycorrhizal symbiosis between plants and fungi is one of the most well-known plant–fungus associations and is of significant importance for plant growth and persistence in many ecosystems; over 90% of all plant species engage in mycorrhizal relationships with fungi and are dependent upon this relationship for survival.

 

A microscopic view of blue-stained cells, some with dark wavy lines in them

The dark filaments are hyphae of the endophytic fungus Epichloë coenophiala in the intercellular spaces of tall fescue leaf sheath tissue

The mycorrhizal symbiosis is ancient, dating back to at least 400 million years. It often increases the plant's uptake of inorganic compounds, such as nitrate and phosphate from soils having low concentrations of these key plant nutrients. The fungal partners may also mediate plant-to-plant transfer of carbohydrates and other nutrients. Such mycorrhizal communities are called "common mycorrhizal networks". A special case of mycorrhiza is myco-heterotrophy, whereby the plant parasitizes the fungus, obtaining all of its nutrients from its fungal symbiont. Some fungal species inhabit the tissues inside roots, stems, and leaves, in which case they are called endophytes. Similar to mycorrhiza, endophytic colonization by fungi may benefit both symbionts; for example, endophytes of grasses impart to their host increased resistance to herbivores and other environmental stresses and receive food and shelter from the plant in return.

 

With algae and cyanobacteria

A green, leaf-like structure attached to a tree, with a pattern of ridges and depression on the bottom surface

The lichen Lobaria pulmonaria, a symbiosis of fungal, algal, and cyanobacterial species

Lichens are a symbiotic relationship between fungi and photosynthetic algae or cyanobacteria. The photosynthetic partner in the relationship is referred to in lichen terminology as a "photobiont". The fungal part of the relationship is composed mostly of various species of ascomycetes and a few basidiomycetes. Lichens occur in every ecosystem on all continents, play a key role in soil formation and the initiation of biological succession, and are prominent in some extreme environments, including polar, alpine, and semiarid desert regions. They are able to grow on inhospitable surfaces, including bare soil, rocks, tree bark, wood, shells, barnacles and leaves. As in mycorrhizas, the photobiont provides sugars and other carbohydrates via photosynthesis to the fungus, while the fungus provides minerals and water to the photobiont. The functions of both symbiotic organisms are so closely intertwined that they function almost as a single organism; in most cases the resulting organism differs greatly from the individual components. Lichenization is a common mode of nutrition for fungi; around 27% of known fungi—more than 19,400 species—are lichenized. Characteristics common to most lichens include obtaining organic carbon by photosynthesis, slow growth, small size, long life, long-lasting (seasonal) vegetative reproductive structures, mineral nutrition obtained largely from airborne sources, and greater tolerance of desiccation than most other photosynthetic organisms in the same habitat.

 

With insects

Many insects also engage in mutualistic relationships with fungi. Several groups of ants cultivate fungi in the order Chaetothyriales for several purposes: as a food source, as a structural component of their nests, and as a part of an ant/plant symbiosis in the domatia (tiny chambers in plants that house arthropods). Ambrosia beetles cultivate various species of fungi in the bark of trees that they infest. Likewise, females of several wood wasp species (genus Sirex) inject their eggs together with spores of the wood-rotting fungus Amylostereum areolatum into the sapwood of pine trees; the growth of the fungus provides ideal nutritional conditions for the development of the wasp larvae. At least one species of stingless bee has a relationship with a fungus in the genus Monascus, where the larvae consume and depend on fungus transferred from old to new nests. Termites on the African savannah are also known to cultivate fungi, and yeasts of the genera Candida and Lachancea inhabit the gut of a wide range of insects, including neuropterans, beetles, and cockroaches; it is not known whether these fungi benefit their hosts. Fungi growing in dead wood are essential for xylophagous insects (e.g. woodboring beetles). They deliver nutrients needed by xylophages to nutritionally scarce dead wood. Thanks to this nutritional enrichment the larvae of the woodboring insect is able to grow and develop to adulthood. The larvae of many families of fungicolous flies, particularly those within the superfamily Sciaroidea such as the Mycetophilidae and some Keroplatidae feed on fungal fruiting bodies and sterile mycorrhizae.

 

A thin brown stick positioned horizontally with roughly two dozen clustered orange-red leaves originating from a single point in the middle of the stick. These orange leaves are three to four times larger than the few other green leaves growing out of the stick, and are covered on the lower leaf surface with hundreds of tiny bumps. The background shows the green leaves and branches of neighboring shrubs.

The plant pathogen Puccinia magellanicum (calafate rust) causes the defect known as witch's broom, seen here on a barberry shrub in Chile.

 

Gram stain of Candida albicans from a vaginal swab from a woman with candidiasis, showing hyphae, and chlamydospores, which are 2–4 µm in diameter.

Many fungi are parasites on plants, animals (including humans), and other fungi. Serious pathogens of many cultivated plants causing extensive damage and losses to agriculture and forestry include the rice blast fungus Magnaporthe oryzae, tree pathogens such as Ophiostoma ulmi and Ophiostoma novo-ulmi causing Dutch elm disease, Cryphonectria parasitica responsible for chestnut blight, and Phymatotrichopsis omnivora causing Texas Root Rot, and plant pathogens in the genera Fusarium, Ustilago, Alternaria, and Cochliobolus. Some carnivorous fungi, like Paecilomyces lilacinus, are predators of nematodes, which they capture using an array of specialized structures such as constricting rings or adhesive nets. Many fungi that are plant pathogens, such as Magnaporthe oryzae, can switch from being biotrophic (parasitic on living plants) to being necrotrophic (feeding on the dead tissues of plants they have killed). This same principle is applied to fungi-feeding parasites, including Asterotremella albida, which feeds on the fruit bodies of other fungi both while they are living and after they are dead.

 

Some fungi can cause serious diseases in humans, several of which may be fatal if untreated. These include aspergillosis, candidiasis, coccidioidomycosis, cryptococcosis, histoplasmosis, mycetomas, and paracoccidioidomycosis. Furthermore, persons with immuno-deficiencies are particularly susceptible to disease by genera such as Aspergillus, Candida, Cryptoccocus, Histoplasma, and Pneumocystis. Other fungi can attack eyes, nails, hair, and especially skin, the so-called dermatophytic and keratinophilic fungi, and cause local infections such as ringworm and athlete's foot. Fungal spores are also a cause of allergies, and fungi from different taxonomic groups can evoke allergic reactions.

 

As targets of mycoparasites

Organisms that parasitize fungi are known as mycoparasitic organisms. About 300 species of fungi and fungus-like organisms, belonging to 13 classes and 113 genera, are used as biocontrol agents against plant fungal diseases. Fungi can also act as mycoparasites or antagonists of other fungi, such as Hypomyces chrysospermus, which grows on bolete mushrooms. Fungi can also become the target of infection by mycoviruses.

 

Communication

Main article: Mycorrhizal networks

There appears to be electrical communication between fungi in word-like components according to spiking characteristics.

 

Possible impact on climate

According to a study published in the academic journal Current Biology, fungi can soak from the atmosphere around 36% of global fossil fuel greenhouse gas emissions.

 

Mycotoxins

(6aR,9R)-N-((2R,5S,10aS,10bS)-5-benzyl-10b-hydroxy-2-methyl-3,6-dioxooctahydro-2H-oxazolo[3,2-a] pyrrolo[2,1-c]pyrazin-2-yl)-7-methyl-4,6,6a,7,8,9-hexahydroindolo[4,3-fg] quinoline-9-carboxamide

Ergotamine, a major mycotoxin produced by Claviceps species, which if ingested can cause gangrene, convulsions, and hallucinations

Many fungi produce biologically active compounds, several of which are toxic to animals or plants and are therefore called mycotoxins. Of particular relevance to humans are mycotoxins produced by molds causing food spoilage, and poisonous mushrooms (see above). Particularly infamous are the lethal amatoxins in some Amanita mushrooms, and ergot alkaloids, which have a long history of causing serious epidemics of ergotism (St Anthony's Fire) in people consuming rye or related cereals contaminated with sclerotia of the ergot fungus, Claviceps purpurea. Other notable mycotoxins include the aflatoxins, which are insidious liver toxins and highly carcinogenic metabolites produced by certain Aspergillus species often growing in or on grains and nuts consumed by humans, ochratoxins, patulin, and trichothecenes (e.g., T-2 mycotoxin) and fumonisins, which have significant impact on human food supplies or animal livestock.

 

Mycotoxins are secondary metabolites (or natural products), and research has established the existence of biochemical pathways solely for the purpose of producing mycotoxins and other natural products in fungi. Mycotoxins may provide fitness benefits in terms of physiological adaptation, competition with other microbes and fungi, and protection from consumption (fungivory). Many fungal secondary metabolites (or derivatives) are used medically, as described under Human use below.

 

Pathogenic mechanisms

Ustilago maydis is a pathogenic plant fungus that causes smut disease in maize and teosinte. Plants have evolved efficient defense systems against pathogenic microbes such as U. maydis. A rapid defense reaction after pathogen attack is the oxidative burst where the plant produces reactive oxygen species at the site of the attempted invasion. U. maydis can respond to the oxidative burst with an oxidative stress response, regulated by the gene YAP1. The response protects U. maydis from the host defense, and is necessary for the pathogen's virulence. Furthermore, U. maydis has a well-established recombinational DNA repair system which acts during mitosis and meiosis. The system may assist the pathogen in surviving DNA damage arising from the host plant's oxidative defensive response to infection.

 

Cryptococcus neoformans is an encapsulated yeast that can live in both plants and animals. C. neoformans usually infects the lungs, where it is phagocytosed by alveolar macrophages. Some C. neoformans can survive inside macrophages, which appears to be the basis for latency, disseminated disease, and resistance to antifungal agents. One mechanism by which C. neoformans survives the hostile macrophage environment is by up-regulating the expression of genes involved in the oxidative stress response. Another mechanism involves meiosis. The majority of C. neoformans are mating "type a". Filaments of mating "type a" ordinarily have haploid nuclei, but they can become diploid (perhaps by endoduplication or by stimulated nuclear fusion) to form blastospores. The diploid nuclei of blastospores can undergo meiosis, including recombination, to form haploid basidiospores that can be dispersed. This process is referred to as monokaryotic fruiting. This process requires a gene called DMC1, which is a conserved homologue of genes recA in bacteria and RAD51 in eukaryotes, that mediates homologous chromosome pairing during meiosis and repair of DNA double-strand breaks. Thus, C. neoformans can undergo a meiosis, monokaryotic fruiting, that promotes recombinational repair in the oxidative, DNA damaging environment of the host macrophage, and the repair capability may contribute to its virulence.

 

Human use

See also: Human interactions with fungi

Microscopic view of five spherical structures; one of the spheres is considerably smaller than the rest and attached to one of the larger spheres

Saccharomyces cerevisiae cells shown with DIC microscopy

The human use of fungi for food preparation or preservation and other purposes is extensive and has a long history. Mushroom farming and mushroom gathering are large industries in many countries. The study of the historical uses and sociological impact of fungi is known as ethnomycology. Because of the capacity of this group to produce an enormous range of natural products with antimicrobial or other biological activities, many species have long been used or are being developed for industrial production of antibiotics, vitamins, and anti-cancer and cholesterol-lowering drugs. Methods have been developed for genetic engineering of fungi, enabling metabolic engineering of fungal species. For example, genetic modification of yeast species—which are easy to grow at fast rates in large fermentation vessels—has opened up ways of pharmaceutical production that are potentially more efficient than production by the original source organisms. Fungi-based industries are sometimes considered to be a major part of a growing bioeconomy, with applications under research and development including use for textiles, meat substitution and general fungal biotechnology.

 

Therapeutic uses

Modern chemotherapeutics

Many species produce metabolites that are major sources of pharmacologically active drugs.

 

Antibiotics

Particularly important are the antibiotics, including the penicillins, a structurally related group of β-lactam antibiotics that are synthesized from small peptides. Although naturally occurring penicillins such as penicillin G (produced by Penicillium chrysogenum) have a relatively narrow spectrum of biological activity, a wide range of other penicillins can be produced by chemical modification of the natural penicillins. Modern penicillins are semisynthetic compounds, obtained initially from fermentation cultures, but then structurally altered for specific desirable properties. Other antibiotics produced by fungi include: ciclosporin, commonly used as an immunosuppressant during transplant surgery; and fusidic acid, used to help control infection from methicillin-resistant Staphylococcus aureus bacteria. Widespread use of antibiotics for the treatment of bacterial diseases, such as tuberculosis, syphilis, leprosy, and others began in the early 20th century and continues to date. In nature, antibiotics of fungal or bacterial origin appear to play a dual role: at high concentrations they act as chemical defense against competition with other microorganisms in species-rich environments, such as the rhizosphere, and at low concentrations as quorum-sensing molecules for intra- or interspecies signaling.

 

Other

Other drugs produced by fungi include griseofulvin isolated from Penicillium griseofulvum, used to treat fungal infections, and statins (HMG-CoA reductase inhibitors), used to inhibit cholesterol synthesis. Examples of statins found in fungi include mevastatin from Penicillium citrinum and lovastatin from Aspergillus terreus and the oyster mushroom. Psilocybin from fungi is investigated for therapeutic use and appears to cause global increases in brain network integration. Fungi produce compounds that inhibit viruses and cancer cells. Specific metabolites, such as polysaccharide-K, ergotamine, and β-lactam antibiotics, are routinely used in clinical medicine. The shiitake mushroom is a source of lentinan, a clinical drug approved for use in cancer treatments in several countries, including Japan. In Europe and Japan, polysaccharide-K (brand name Krestin), a chemical derived from Trametes versicolor, is an approved adjuvant for cancer therapy.

 

Traditional medicine

Upper surface view of a kidney-shaped fungus, brownish-red with a lighter yellow-brown margin, and a somewhat varnished or shiny appearance

Two dried yellow-orange caterpillars, one with a curly grayish fungus growing out of one of its ends. The grayish fungus is roughly equal to or slightly greater in length than the caterpillar, and tapers in thickness to a narrow end.

The fungi Ganoderma lucidum (left) and Ophiocordyceps sinensis (right) are used in traditional medicine practices

Certain mushrooms are used as supposed therapeutics in folk medicine practices, such as traditional Chinese medicine. Mushrooms with a history of such use include Agaricus subrufescens, Ganoderma lucidum, and Ophiocordyceps sinensis.

 

Cultured foods

Baker's yeast or Saccharomyces cerevisiae, a unicellular fungus, is used to make bread and other wheat-based products, such as pizza dough and dumplings. Yeast species of the genus Saccharomyces are also used to produce alcoholic beverages through fermentation. Shoyu koji mold (Aspergillus oryzae) is an essential ingredient in brewing Shoyu (soy sauce) and sake, and the preparation of miso while Rhizopus species are used for making tempeh. Several of these fungi are domesticated species that were bred or selected according to their capacity to ferment food without producing harmful mycotoxins (see below), which are produced by very closely related Aspergilli. Quorn, a meat substitute, is made from Fusarium venenatum.

U.S. Department of Agriculture (USDA) Agricultural Research Service (ARS) Research Entomologist Christopher (Chris) Geden, PhD., uses a petri dish to hold a collection of adult house flies that have been infected with Beauveria bassiana for studies about the effect of using artificial sweeteners and fungal pathogens on them at the ARS Center for Medical, Agricultural, and Veterinary Entomology, in Gainesville, FL, on February 24, 2021.

 

Geden works to find chemical insecticide alternatives to manage house fly populations. Here he is studying the use of fungal pathogens combined with artificial sweeteners. The sweetener attracts the flies and is lethal to them as well. Unlike sugar, the sweetener does not give them energy, just indigestion resulting in death by dehydration. At the same time, the fly is inoculated with fungal spores of a pathogen that will also kill them, and their cadavers will produce a new crop of spores that are spread by contact. Neither the sweetener nor the pathogen can harm humans.

House and stable flies are major pests of animal agriculture in the US and throughout the world. Management of these flies using insecticides can be problematic because the flies have developed resistance to many of the available products. The growing market for organic products creates additional demands for alternatives to chemical insecticides. Although their mode of action is not known, the artificial sweeteners xylitol and erythritol are toxic to adult flies of several species. Scientists at Northern Illinois University and ARS evaluated the effect of these sweeteners on the larvae of house flies and stable flies. These sweeteners appear to have potential as an inexpensive way to control flies without using conventional insecticides. Caption derived from ars.usda.gov/research/publications/publication/?seqNo115=356216

USDA Media by Lance Cheung.

Pathogen: Undetermined

Scott planting tanoak seedlings. Field trial to examine genetic variation in resistance to Sudden Oak Death (Phytophthora ramorum) in tanoak, Douglas-fir, coast redwood, and Port-Orford-cedar. Established near Brookings, Oregon.

 

More about the project from Richard Sniezko:

A field trial was established in southern Oregon, near Brookings, in March 2019 to examine genetic variation in resistance to Phytophthora ramorum (pathogen causing Sudden Oak Death) in tanoak, as well as susceptibility of conifers Douglas-fir, coast redwood, and Port-Orford-cedar. The trial was a joint effort between USFS (Dorena Genetic Resource Center, FHP), OSU, and ODF.

 

900 tanoak (Notholithocarpus densiflorus) seedling ‘families’ from 55 Oregon parent trees (and bulked lots) were planted in a field trial to assess genetic resistance to Phytophthora ramorum (pathogen causing sudden oak death, SOD), and to correlate with results of seedling inoculation testing done at Oregon State University. Douglas-fir (Pseudotsuga menziesii), coast redwood (Sequoia sempervirens), and Port-Orford-cedar (Chamaecyparis lawsoniana) seedlings were also planted to test conifer susceptibility. Contact Richard Sniezko (richard.sniezko@usda.gov), Megan Lewien (mlewien@fs.fed.us), and Jared LeBoldus (Jared.LeBoldus@oregonstate.edu), for more information.

 

Photo by: Richard Sniezko

Date: March 19, 2019

 

Credit: USDA Forest Service, Region 6, Umpqua National Forest, Dorena Genetic Resource Center.

Source: Richard Sniezko collection; Cottage Grove, Oregon.

 

For more about the Dorena Genetic Resource Center see: www.fs.usda.gov/detail/r6/landmanagement/resourcemanageme...

 

Image provided by USDA Forest Service, Region 6, State and Private Forestry, Forest Health Protection: www.fs.usda.gov/main/r6/forest-grasslandhealth

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Breaking News; or, Janus of the Third Kind

 

In America new information (& if & when used, older information as well) must be instantly converted into money. The conversion is achieved not by respecting the information for its positive or negative truth or social value & publishing it straightforwardly, but rather by respecting it only as a device to be immediately changed into any imagined substitute form that might maximize the amount of money obtainable for oneself or for the organization one is employed by or is promoting.

 

Such convertibility is inherently part of Schismogenic Economic practices & theory - that is, runaway capitalism - & schismogenesis in both of its virulent forms, Complementary & Symmetrical, is essential to the growth of the not entirely original but hugely admired & infectious American pathogen.

 

Civilizations were made possible by the Agricultural Revolution which began 10,000 years ago, & all were modeled from the easy, briefly profitable for some persons but in the long run always fatal disease of Class Differences - fatal to the poor, the rich & every civilization contaminated by it. The upper class is a clinging class, & as such avidly rejects changes that in the long run are plainly necessary to both its own survival & the survival of the culture in which it functions. Likewise, institutions that serve the upper class, especially their religious ones, resist almost all change, no matter how profoundly ignorant & blindly stubborn doing do makes them appear. Witness all of the right wing 'think' tanks that manufacture propaganda designed to prevent the public from seeing that the masters of the world are destroying it as rapidly & wantonly as possible - the oligarchs & the upper tier of their minions rush headlong to kill the goose that lays their golden eggs.

 

The present evolution of the virus may be summed up in the 2002 disconnected from reality, postmodernist radical relativistic fantasy of Turd Blossom, as George W. Bush called his chief political advisor, Karl Rove, first quoted by Ron Suskind in The New York Times in an article published in 2004:

 

In the summer of 2002, after I [Suskind] had written an article in Esquire that the White House didn't like about Bush's former communications director, Karen Hughes, I had a meeting with a senior adviser to Bush. He expressed the White House's displeasure, and then he told me something that at the time I didn't fully comprehend -- but which I now believe gets to the very heart of the Bush presidency.

 

The aide [since learned to be Karl Rove] said that guys like me were ''in what we call the reality-based community,'' which he defined as people who ''believe that solutions emerge from your judicious study of discernible reality.'' I nodded and murmured something about enlightenment principles and empiricism. He cut me off. ''That's not the way the world really works anymore,'' he continued. ''We're an empire now, and when we act, we create our own reality. And while you're studying that reality -- judiciously, as you will -- we'll act again, creating other new realities, which you can study too, and that's how things will sort out. We're history's actors . . . and you, all of you, will be left to just study what we do.''

 

I am not shaping a literary conceit. Just as Schismogenic Economics is a financial pillar, postmodernist Radical Relativism is the ideological pillar of the conversion of news into nooze, which largely but not exclusively consists of the magical & often criminal transformation of matters of truth, falsity & social policy into mere opinion presented to audiences as schizophrenic 'debates' that grip & hold bamboozled TV viewers & readers so that their innocent & humanly gullible attention can be used to obtain money & wealth from advertisers for corporate networks & publishers.

 

Look at the photograph.

 

When one receives information that is presented not from its face, but from its ass, it may be brightly lit & greatly detailed, but it is unreadable & confusing. Hypnotists are familiar with & employ the power of confusion. They commonly make a series of nonsense statements when inducing a trance state in their subjects, especially the more self-contained & resistant ones. It is officially called the Confusion Technique. It works to successfully bring about the trance state with a significant percentage of even the most strongly sane people. The trance occurs at the very moment when in a flowing stream of purposefully expressed grammatically constructed but meaningless nonsense the hypnotist abruptly voices a clear, understandable command, such as "Go to sleep," to which immediately is added, "You will now cease hearing & be unable to obey any voice or instruction that is not made by me."

 

Turn on your TV. Tune in to nooze. Poverty in the nation's ghettoes is made into money to fill the coffers of nooze corporations & their owners. Blacks & Latins are especially useful for this last purpose, & no expenditures for professional writers, actors, musical composers, journalists or photographers are incurred. You will see Tea Parties being made into money. Crimes of every sort are there being used to scare you so that you will keep tuning in, thus converting your anxiety & its mental & physical health consequences into money for the superrich. Listen to Glenn Beck, or Ann Coulter, whose crafted lies & clever appearance of insanity are used to grab your attention & make it into invisible people's wealth. Look at our abominable politicians, especially but not exclusively on the right, who without conscience willfully assert that there is a plan in this or that bill before Congress to allow Unicorns & Flibbertigibbets to cut off your nose & use it to grow jelly beans, which causes you to be afraid & converts your fear into their power & vast Wall Street wealth - wealth you are completely deprived of possessing any part of.

 

Can you tune into it without turning into it? I find that dosing myself with TV neurotoxins harms my mind & its moods, so I seek & find information where there are barriers to poisons.

 

Nooze is not news. News does not break wind.

Abstract

Space medicine research has drawn immense attention toward provision of efficient life support systems during long-term missions into space. However, in extended missions, a wide range of diseases may affect astronauts. In space medicine research, the gastrointestinal microbiome and its role in maintaining astronauts' health has received little attention.

We would like to draw researchers' attention to the significant role of microbiota. Because of the high number of microorganisms in the human body, man has been called a 'supra-organism' and gastrointestinal flora has been referred to as 'a virtual organ of the human body'.

In space, the lifestyle, sterility of spaceship and environmental stresses can result in alterations in intestinal microbiota, which can lead to an impaired immunity and predispose astronauts to illness. This concern is heightened by increase in virulence of pathogens in microgravity. Thus, design of a personal probiotic kit is recommended to improve the health status of astronauts.

Introduction

Living in space has been a great desire for mankind, leading to the development of space stations for long-duration manned space missions. The design of a life support system is needed to maintain the minimum life requirements for humans in space by conserving a stable body temperature, a standard pressure on the body and by managing waste products.

So far, the majority of research in this area has been devoted to the human primary requirements such as air, water and food. Furthermore, a life support system deals with astronauts' healthcare. Although health status of the astronauts such as immunological and physiological problems has been investigated, less attention has been paid to the intestinal microbiome and its significant role in the astronaut's health.

Immunological and physiological health problems could occur when considering the identified increase in the virulence and antibiotic resistance of some infectious bacteria exposed to microgravity, along with possible weakening of the immune system during space flight. Compensating for these alterations may not only enhance the health and immunity status of astronauts, but might have possible effects on enhancing the duration of space journeys.

For many years, the importance of intestinal flora in human health and disease has been known to man. Researchers have suggested a possible association between the changes in the balance of gut flora and several diseases. At the end of the Human Genome Project, the aggregation of flora genes within the human genome was named the 'human metagenome, highlighting the crucial role of the microbiome in the maintenance of health.

This perspective highlights the crucial role of the microbiome in the health and/or disease status in astronauts. Considering astronauts' special health and nutrition needs in orbit, it could be advantageous to develop probiotics for each crew member. These healthy bacteria could then be consumed during long-duration missions to replenish the intestinal microbiome.

The Human Intestine & the Microbiome

Today 'gut health' is a term increasingly used in the medical literature to describe effective digestion and absorption, the absence of gastrointestinal lesions, presence of normal intestinal microflora and proper immune function. However, from a scientific point of view, it is still extremely unclear what gut health is or how it can be defined and/or measured.

The interactions between the gastrointestinal barrier and the microbiome appear to be a complex mechanism that assists in maintaining gut health. The gastrointestinal tract contributes to digestion and absorption of nutrients, minerals and fluids, osmoregulation, endocrine regulation and host metabolism, mucosal and systemic tolerance, immunoenhancement, defense against potential pathogens and harmful substances, signaling from the periphery to the brain, and detoxification of toxic molecules originating from the environment or the host.

Recognition of the importance of gastrointestinal health and microflora can be an important asset to astronauts' health.

Across the large surface of the digestive tract, healthy and pathogenic bacteria compete for dominance. With such a huge exposure area, the immune system has a hard task of hindering pathogens from entering the blood and lymph. The presence of a balance between beneficial and potentially harmful bacteria is considered normal and contributes to a dynamic and healthy human gut.

One way to maintain this homeostasis is to introduce helpful bacteria or probiotics. After the first suggestion of the health benefits of probiotics in the early 20th century by Nobel Laureate Metchnikoff, many bacterial strains have been clinically tested as potential probiotics. Probiotics are thought to play a health-promoting role by improving intestinal microbial infections.

The surface area, apparent balance of microflora and health impact of the human gut reminds us that this complex organ must not be forgotten as one factor in long-duration spaceflight health.

Stress & Gut Microbiome

The Human Genome Project revealed that the human body is the habitat of microbial symbionts ten-times more in number than Homo sapiens cells. The recognition of the complex interactional environment between the human and our symbiotic microflora led researchers to name this the 'human microbiome'.

In the human gut, the microbiome directly influences biochemical, physiological and immunological pathways and is the first line of resistance to various diseases.

Traveling can act as an environmental stress causing changes in the microbiome composition or its gene expression. This may lead to the transient (as in travelers' diarrhea) or permanent dominance of pathogenic gut bacteria. Recently, it was shown that exposure to a social stressor altered the composition of the intestinal microbiome, indicating stressor-induced immunomodulation.

It was demonstrated that stressor exposure changes the stability of the microflora and leads to bacterial translocation. Circulating levels of IL-6 and MCP-1 increased with stressor exposure and these increases were significantly and positively correlated to changes in three bacterial genera (i.e., Coprococcus, Pseudobutyrivibrio and Dorea) in the cecum.

This suggested that the microbiome somehow contributed to stressor-induced immunoenhancement. To test the theory, in follow-up experiments, mice were treated with an antibiotic cocktail to determine whether reducing microflora would annul this stressor-induced increase in circulating cytokines.

In the antibiotic-treated mice, exposure to the same stressor failed to increase IL-6 and MCP-1 confirming that intestinal microflora were necessary for the observed increase in circulating cytokines.

Microgravity Stress Alters Bacterial Virulence

Studies have shown an increase in the virulence, changes in growth modulation and alterations in response to antibiotics in certain bacteria both in space and simulated microgravity. Significant technological and logistical hurdles have hindered thorough genotypic and phenotypic analyses of bacterial response to actual space environment.

In this line, Wilson et al. cultured Salmonella enterica Typhimurium aboard space shuttle mission STS-115 with identical cultures as ground controls. Global microarray and proteomic analyses were carried out and 167 differentially expressed transcripts and 73 proteins were identified among which conserved RNA-binding protein Hfq was suggested as a likely global regulator involved in the response to spaceflight.

Similar results were obtained with ground-based microgravity culture model. Furthermore, spaceflight-grown S. enterica Typhimurium had enhanced virulence in murine models and exhibited extracellular matrix accumulation consistent with a biofilm. Typhimurium grown in spaceflight analog exhibited increased virulence, increased resistance to environmental stresses (acid, osmotic and thermal stress), increased survival in macrophages and global changes in gene expression.

Low-shear modeled microgravity rendered adherent–invasive Escherichia coli more adherent to a mammalian gastrointestinal epithelial-like cell line, Caco-2. Simulated microgravity conditions markedly increased production of the heat-labile enterotoxin from enterotoxigenic E. coli. Upon a 12-day exposure to low-shear modeled microgravity, Candida albicans exhibited increased filamentation, formation of biofilm communities, phenotypic switching and more resistance to the antifungal agent amphotericin B.

Only one virulence gene was found among 163 differentially expressed genes in simulated microgravity grown S. Typhimurium and actually, most virulence genes were expressed at a lower level (including genes involved in lipopolysaccharide production). Furthermore, sigma factor (a transcription factor responsible for a general stress response) was not thought to be a cause, since a decreased level of its gene expression was observed in simulated microgravity.

The mechanism of enhanced virulence of S. Typhimurium grown in actual spaceflight and rotating wall vessel culture conditions does not involve an increased expression of traditional genes that regulate the virulence of this bacterium under normal gravity conditions; however, Hfq pathway is required for full virulence in S. Typhimurium.

Biofilm formation is part of the normal growth cycle of most bacteria and this film is linked to chronic diseases that are difficult to treat such as endocarditis, cystitis and bacterial otitis media. Bacterial biofilm creates superior resistance to oxidative, osmolarity, pH and antibiotic stresses.

Theoretically, bacterial biofilm production, which enhances bacterial survival by resistance to the immune system and antimicrobial agents, may increase the risk and/or severity of infection in long-term space missions. Diminished gravity has been shown to stimulate bacterial biofilm formation both in E. coli and Pseudomonas aeruginosa. In a study by Crabbe et al. in 2008, rotating wall vessel technology was exploited to study the effect of microgravity on growth behavior of P. aeruginosa PAO1.

Rotating wall vessel cultivation resulted in a self-aggregating phenotype, which subsequently led to formation of biofilms. In a second study in 2010, the same researchers employed microarrays to investigate the response of P. aeruginosa PAO1 to low-shear modeled microgravity both in rotating wall vessel and random position machine.

P. aeruginosa demonstrated increased alginate production and upregulation of AlgU-controlled transcripts (including those coding for stress-related proteins) in modeled microgravity. Results of the study also implicated the involvement of Hfq in response of P. aeruginosa to simulated microgravity. Involvement of Hfq in response of P. aeruginosa to actual spaceflight was later confirmed in another study.

In addition, there is concern that antibiotic-resistance increases during short-term spaceflight. The MIC of both colistin and kanamycin increased significantly in E. coli grown aboard the flight module compared with the MIC on the ground. A similar increase in the MIC of oxacillin, erythromycin and chloramphenicol was reported in Staphylococcus aureus. This has led to concerns that the efficacy of antibiotics may be diminished during even short orbital missions.

It has been hypothesized that reduction in the natural, terrestrial diversity of the gastrointestinal bacterial microflora in spaceflight may give rise to an increase in the presence of the drug-resistant bacteria. It has also been postulated that the emergence of such resistant clones could be facilitated by the administration of antibiotics either before or during the flight.

Emergence of drug resistance is also facilitated by bacterial mutation which occurs more frequently in long-term spaceflights. Overall, there is the possibility that drug-resistant bacteria could colonize all crew members on a mission, giving rise to a difficult-to-treat healthcare problem.

Spaceflight & the Microbiome

In an attempt to protect astronauts from exposure to novel pathogens preflight, several guidelines are carried out. Prelaunch, crew members are limited both in travel and visitors to limit pathogen exposure. Therefore, crew members tend to launch with normal gut microflora and with a reduced risk of gut infection.

Items flown to the International Space Station (ISS) are cleaned before loading to limit introducing bacteria to the environment. Once in orbit, all areas in the ISS have ultra-high-efficiency bacterial filters in the air supply ducts to reduce the levels of bacteria and fungi. Finally, cleaning of the surfaces of the modules is a regular 'housekeeping' chore to limit bacterial and fungal growth.

Still, microorganisms exist on the ISS. No matter how much cleaning is done, microorganisms are continuously shed from skin, mucous membranes, gastrointestinal and respiratory tracts or can be released by sneezing, coughing and talking. Specimens were obtained for mycological examination from the skin, throat, urine and feces of the six astronauts who conducted the Apollo 14 and Apollo 15 lunar exploration missions both before and after flight.

Analysis of preflight data demonstrated that the process of severely restricting opportunities for colonization for 3 weeks before flight resulted in a 50% reduction in the number of isolated species. Postflight data indicated that exposure to the spaceflight environment for up to 2 weeks resulted in an even greater reduction with a relative increase in the potential pathogen C. albicans.

The compositions of intestinal, oral and nasal flora have been shown to change even during short spaceflights. In one study, a reduction in the number of nonpathogenic bacteria and an increase in the number of opportunistic pathogens has been reported in the nasal flora of cosmonauts. A significant reduction in the number of bacterial species of the intestine has been seen after 2 weeks of spaceflight.

These observations were similar to changes seen in ground volunteers who were kept in isolation, in which volunteers were fed only sterilized, dehydrated foods. A significant decrease in the number of bifidobacteria, lactobacilli and other bacteria was seen. In a Russian experiment, a decrease in lactobacilli (and replacement with pathogens) were seen in mouth and throat cavities in all mission members in in-flight period.

Spaceflights and even the preparation phase before take-off can exert dysbiosis in the human microflora which results in reduction of the defense group of microorganisms (bifidobacteria and lactobacilli) and appearance of opportunistic pathogens such as E. coli, enterobacteria and clostridia. Subsequently, this procedure can lead to accumulation of the potentially pathogenic species and their long-term persistence.

Colonization resistance is one of the factors that needs to be taken into account to stabilize the microflora of the cosmonauts during space flights. Indigenous microflora are vital for preservation of microecological homeostasis. It has been hypothesized that a regular intake of probiotic foods might be helpful in correcting this change.

Human microflora functions as a barrier against antigens from microorganisms and food. Alterations in the microbiome composition have been reported in inflammatory bowel disease, inflammatory conditions, ulcerative colitis and more. Healthy immunophysiologic regulation in the gut has been hypothesized to depend on the establishment of indigenous microflora that create specific immune responses at the gut and system levels.

Furthermore, gut microflora has a role in induction and maintenance of oral tolerance in experimental animal models. Changes in the diversity and number of gut microflora have been linked to a deficient immune system as well as immunological dysregulation which is associated with many human noninfectious diseases such as autoimmunity, allergy and cancer.

Reinforcing this concept of health symbiosis, studies of germ-free animal showed wide-ranging defects in the development and maturation of gut-associated lymphoid tissues. Another way of viewing this health interaction comes from the data that ten Salmonella bacteria have been shown to induce infection in germ-free mice, while 109 bacteria are needed to induce infection in a conventional animal possessing intact intestinal microflora.

To maintain astronaut health on orbit, an awareness of the importance of a balanced gut microbiome to maintaining the immune homeostasis and resistance to infections is valuable.

Previous studies have shown that important immune parameters are decreased during spaceflight. Reductions in the number and proportion of lymphocytes and their cytokine production, depression of dendritic cells function and T-cell activation, and finally reduction in numbers of monocytes and precursors of macrophages, have been noted.

In one study, stresses associated with spaceflight were shown to alter important functions of neutrophils and monocytes. In another study, the astronauts' monocyte functions showed reductions in their ability to engulf E. coli, elicit an oxidative burst and degranulation. Non-MHC-restricted (CD56) killer cell cytotoxicity tends to decrease after short-term spaceflight.

In the latter study, the authors examined the age, gender (nine men and one woman), flight experience, mission factors and mission role (e.g., pilot, scientist or crew) of the astronauts and found no correlation between these variables and individual non-MHC killer cell function levels.

Therefore, other factors may contribute to the compromised immune system in space. Decreased natural killer cell cytotoxicity in cosmonauts after short- and long-term spaceflights have also been reported. Reductions in absolute numbers of lymphocytes, eosinophils and natural killer cells, reduced lymphocyte mitogenic response, diminished delayed-type hypersensitivity, changes in CD4+:CD8+ ratios and reduced production of IL-2 and IFN-γ have also been reported.

The immune system changes of astronauts as well as environmental stress may have been a factor in known incidents of infectious illness in crew members. During the Apollo 8 preflight period for instance, all crew members suffered viral gastroenteritis. During flight, the effects of mission duration on the neuroimmune responses in astronauts were studied and changes in plasma cortisol, epinephrine, norepinephrine, total IgE levels, number of white blood cells, polymorphonuclear leukocytes and CD4+ T cells were found at different times.

  

Upper respiratory problems, influenza, viral gastroenteritis, rhinitis, pharyngitis or mild dermatologic problems were among the illnesses that astronauts faced during Apollo spaceflights. Reactivation of varicellas zoster virus, herpes virus and shedding of Epstein–Barr virus was also found in space shuttle crew members.

  

In astronauts of the Mir station, analyses demonstrated a significant number of episodes of microbial infections, including conjunctivitis, acute respiratory events and dental infections. Future Perspective: Considering Probiotics as a Countermeasure

On Earth, probiotics have been shown to improve both innate and adaptive immune responses. Oral bacteriotherapy with probiotic bacterial strains is believed to improve the intestine's immunologic barrier, particularly through intestinal IgA responses and alleviation of inflammatory reactions. A gut-stabilizing effect seems to occur through a balance between proinflammatory and anti-inflammatory cytokines.

Lactobacillus rhamnosus GG has been shown to inhibit TNF-α-induced IL-8 secretion of human colon adenocarcinoma (HT29) cells and to reduce elevated fecal concentration of TNF-α in patients with atopic dermatitis and cow milk allergy. On the other hand, ingestion of lactobacilli in fermented milk products or as live-attenuated bacteria potentiated the IFN-γ production by peripheral blood mononuclear cells.

Oral administration of lactobacilli increased the systemic and mucosal IgA response to dietary antigens. Oral supplementation with Bifidobacterium bifidum and Bifidobacterium breve enhanced the antibody response to ovalbumin and stimulated the IgA response to cholera toxin in mice. An increase in the humoral immune response including an increase in rotavirus-specific antibody-secreting cells in the IgA class was also detected in children and individuals receiving L. rhamnosus GG.

Isolauri et al. reported that infants receiving a reassortant live oral rotavirus vaccine in conjunction with L. rhamnosus GG had a higher frequency of rotavirus-specific IgM class antibody-secreting cells. An increased incidence of rotavirus-specific IgA antibody class seroconversion compared with placebo subjects was also seen. IgA+ cells and IL-6-producing cells increased in number after 7 days of Lactobacillus casei administration.

In another study, administration of lactic acid bacteria stimulated the gut immune cells to release inflammatory cytokines such as TNF-α, IFN-γ and IL-12, and regulatory cytokines like IL-4 and IL- 10 in a dose- and strain-dependent manner. Several lactobacilli strains have been shown to promote the immunopotentiator capacity of cells of the innate immune system, including macrophages. Examples of probiotics that can modulate the gut immune system are abundant and have been reviewed extensively.

Buckley et al. have suggested that consumption of soy-based fermented products (containing lactic acid bacteria) can prevent the health problems of astronauts associated with long-term space travel. Assessment of soy-based fermented products by in vitro challenge system (using TNF-α) with human intestinal epithelial and macrophage cell lines has demonstrated the ability of the intervention to downregulate production of the proinflammatory cytokine IL-8.

Considering the importance of the human gut in healthy digestion, nutrient absorption and exposure to pathogens across its large surface area, a healthy digestive tract is important to a healthy human. Diet, lifestyle, antibiotic therapy, different kinds of stressful conditions and so on, can exert alterations in an astronaut's gut microbiome in space.

Considering potential immune system alterations from gut microflora changes, antibiotic use in orbit and changes of increased virulence and antibiotic resistance of bacteria in space, physicians who care for astronauts must remember the importance of the intestinal microbiome to their health status. From this perspective, an impaired digestive system might endanger the mission as well as the health of the astronaut. One countermeasure to be considered would be replenishing the astronaut's intestinal microflora by introducing immune-enhancing probiotic bacteria periodically during the mission.

Diet, lifestyle, antibiotic therapy and various environmental stresses, and so on, can exert alterations in an astronaut's gut microbiome in space and impair their immune system.

Although single probiotics have sometimes been shown to promote health, the human microbiome is composed of more than 400 microbial species, most of which remain uncultured and have as yet unknown functions. The Human Microbiome Project will certainly pave the way for us to increase our understanding of these microbial entities.[4] Thus, providing only a single probiotic might not be the answer.

Contrary to numerous previous investigations and clinical trials in which only effects of single or a couple of probiotics have been studied, we think multiprobiotic therapy and/or designing individualized probiotic kits seems a more reasonable option. A series of experiments need to be launched to confirm the efficacy and safety of using probiotics in space.

Safety studies are of equal importance as efficacy studies, since astronauts are immunocompromised (although as discussed above, much of this may return to washing out of microflora in space). These studies can be carried out initially in ground-based space analogs and further followed in actual space (first on animal models and then on humans). The lifestyle of astronauts can be simulated in these studies and after interventions; the composition of microbiota (including opportunistic pathogens) along with immunological markers should be determined.

Both short- and long-term confinement and actual spaceflight studies can be designed. The administration and/or consumption of probiotics is supposed to have immune-enhancing effects, hinder alterations in the human microbiome to a large extent and prevent colonization of potential pathogens. Upon observation of possible benefits, probiotics can be incorporated into astronauts' food or supplied periodically as a probiotic kit.

This line of research can be followed by NASA scientists and other space agencies to enhance the quality of life of astronauts and to contribute to human presence in space.

Surprisingly, this may bring a future where astronauts utilize probiotic bacteria to counteract the potential effect of pathogenic bacteria during spaceflight.

www.uber-nutra.com

This unidentified fungus was isolated from parasitized egg masses of Meloidogyne incognita, a species of root-knot nematode that was infecting roots of tomato ('Orange Pixie').

 

The fungus probably produces chitinase, an enzyme that degrades chitin, a principal component of the nematode's egg shells.

 

This fungus was also applied to a colony of living banana aphids (Pentalonia nigronervosa), where it killed and colonized individual aphids.

 

The exoskeletons of aphids and other insects also have chitin as a primary component.

 

Here the fungus grows on 10% V8 juice agar.

A small sample of tissue from a plant showing symptoms of fungal infection is placed on agar medium in order to isolate and identify the pathogen. CIMMYT staff demonstrated the techniques they use for isolation to participants in a weeklong seed health workshop. This was held during 29 November-03 December 2010 and based at CIMMYT's headquarters at El Batán, Mexico, with participants spending most of their time in CIMMYT's Seed Health Laboratory.

 

It was attended by 11 technicians from ten Mexican states, from State Committees of Plant Health and from the National Institute of Forestry, Agriculture, and Livestock Research (INIFAP). They explored various detection methods for seed borne fungi, bacteria, and viruses affecting maize and wheat, with the aim of promoting protocol consistency among Mexican seed technicians.

 

The workshop was the first of its kind, and due to resounding positive feedback, it is hoped that it will be continued annually.

 

For more about the workshop, see CIMMYT's blog story at: blog.cimmyt.org/?p=5965.

 

Photo credit: Xochiquetzal Fonseca/CIMMYT.

A Senecio vulgaris groundsel with powdery mildew and orange crown rust.

bug on mesh

F1K9 Canine Trainer / Handler Jessica Kohntopp with agricultural disease Detection Dog (in-training) Pepper (a Belgian Malinois dog) quickly and accurately inspect rows of pepper plants; part of their work with U.S. Department of Agriculture (USDA) Agricultural Research Service (ARS) scientists from the U.S. Horticultural Research Laboratory, in Fort Pierce, FL, to train dogs to detect huanglongbing (HLB; a.k.a. citrus greening) in citrus, squash vein yellowing virus (SqVYV; cause of viral watermelon vine decline) in squash, and tomato chlorotic spot virus (TCSV) in pepper plants at this training session in New Smyrna Beach, FL, on Feb. 25, 2021.

When a dog detects - smell - a diseased plant, its response is to sit or lie facing the plant until it is rewarded with a few seconds of play.

F1K9, a licensed canine detection service company.

 

Dogs can be trained to detect specific bacterial or viral pathogens in any part of a plant with greater than 99% accuracy, significantly faster than laboratory tests, and before visible symptoms are obvious. Conventional analysis typically uses only one leaf from a plant. At the early stages of infection, before the disease spreads throughout the plant, a healthy leaf may be taken from an infected plant resulting in a negative laboratory test. In contrast, dogs sample the entire plant while walking by and sniffing it. For more information, please go to ars.usda.gov/news-events/news/research-news/2020/trained-dogs-are-the-most-efficient-way-to-hunt-citrus-industrys-biggest-threat/. USDA Photo by Lance Cheung.

F1K9 Canine Trainer / Handler Jessica Kohntopp with agricultural disease Detection Dog (in-training) Pepper (a Belgian Malinois dog) quickly and accurately inspect rows of pepper plants; part of their work with U.S. Department of Agriculture (USDA) Agricultural Research Service (ARS) scientists from the U.S. Horticultural Research Laboratory, in Fort Pierce, FL, to train dogs to detect huanglongbing (HLB; a.k.a. citrus greening) in citrus, squash vein yellowing virus (SqVYV; cause of viral watermelon vine decline) in squash, and tomato chlorotic spot virus (TCSV) in pepper plants at this training session in New Smyrna Beach, FL, on Feb. 25, 2021.

When a dog detects - smell - a diseased plant, its response is to sit or lie facing the plant until it is rewarded with a few seconds of play.

F1K9, a licensed canine detection service company.

 

Dogs can be trained to detect specific bacterial or viral pathogens in any part of a plant with greater than 99% accuracy, significantly faster than laboratory tests, and before visible symptoms are obvious. Conventional analysis typically uses only one leaf from a plant. At the early stages of infection, before the disease spreads throughout the plant, a healthy leaf may be taken from an infected plant resulting in a negative laboratory test. In contrast, dogs sample the entire plant while walking by and sniffing it. For more information, please go to ars.usda.gov/news-events/news/research-news/2020/trained-dogs-are-the-most-efficient-way-to-hunt-citrus-industrys-biggest-threat/. USDA Photo by Lance Cheung.

F1K9 Canine Trainer / Handler Jessica Kohntopp with agricultural disease Detection Dog (in-training) Pepper (a Belgian Malinois dog) quickly and accurately inspect rows of pepper plants; part of their work with U.S. Department of Agriculture (USDA) Agricultural Research Service (ARS) scientists from the U.S. Horticultural Research Laboratory, in Fort Pierce, FL, to train dogs to detect huanglongbing (HLB; a.k.a. citrus greening) in citrus, squash vein yellowing virus (SqVYV; cause of viral watermelon vine decline) in squash, and tomato chlorotic spot virus (TCSV) in pepper plants at this training session in New Smyrna Beach, FL, on Feb. 25, 2021.

 

F1K9, a licensed canine detection service company. When the dogs detect - smell - a diseased plant, its response is to sit or lie facing the plant until it is rewarded with a few seconds of play.

 

Dogs include Belgian Malinois, German Shepherd, and a Vizsla. When a dog detects - smells - a diseased plant, its response is to sit facing the plant until it is rewarded with a few seconds of play.

 

Dogs can be trained to detect specific bacterial or viral pathogens in any part of a plant with greater than 99% accuracy, significantly faster than laboratory tests, and before visible symptoms are obvious. Conventional analysis typically uses only one leaf from a plant. At the early stages of infection, before the disease spreads throughout the plant, a healthy leaf may be taken from an infected plant resulting in a negative laboratory test. In contrast, dogs sample the entire plant while walking by and sniffing it. For more information, please go to ars.usda.gov/news-events/news/research-news/2020/trained-dogs-are-the-most-efficient-way-to-hunt-citrus-industrys-biggest-threat/. USDA Photo by Lance Cheung.

Beta Haemolytic Group G Streptococcus on Columbia Horse Blood Agar

The bright yellow infected pepper plants have been devastated the tomato chlorotic spot virus (TCSV), in Palm Beach County, Florida, on January 6, 2017.

 

U.S. Department of Agriculture (USDA) Agricultural Research Service (ARS) scientists from Fort Pierce, FL and F1 K9, a licensed canine detection service company, to train dogs to detect TCSV, in New Smyrna Beach, FL, on Feb. 25, 2021.

 

Dogs can be trained to detect specific bacterial or viral pathogens in any part of a plant with greater than 99% accuracy, significantly faster than laboratory tests, and before visible symptoms are obvious. Conventional analysis typically uses only one leaf from a plant. At the early stages of infection, before the disease spreads throughout the plant, a healthy leaf may be taken from an infected plant resulting in a negative laboratory test. In contrast, dogs sample the entire plant while walking by and sniffing it. For more information, please go to ars.usda.gov/news-events/news/research-news/2020/trained-dogs-are-the-most-efficient-way-to-hunt-citrus-industrys-biggest-threat/. USDA/ARS photo by Scott Atkins.

ant feast on home floor

The bright yellow infected pepper plants have been devastated the tomato chlorotic spot virus (TCSV), in Palm Beach County, Florida, on January 6, 2017.

 

U.S. Department of Agriculture (USDA) Agricultural Research Service (ARS) scientists from Fort Pierce, FL and F1 K9, a licensed canine detection service company, to train dogs to detect TCSV, in New Smyrna Beach, FL, on Feb. 25, 2021.

 

Dogs can be trained to detect specific bacterial or viral pathogens in any part of a plant with greater than 99% accuracy, significantly faster than laboratory tests, and before visible symptoms are obvious. Conventional analysis typically uses only one leaf from a plant. At the early stages of infection, before the disease spreads throughout the plant, a healthy leaf may be taken from an infected plant resulting in a negative laboratory test. In contrast, dogs sample the entire plant while walking by and sniffing it. For more information, please go to ars.usda.gov/news-events/news/research-news/2020/trained-dogs-are-the-most-efficient-way-to-hunt-citrus-industrys-biggest-threat/. USDA/ARS photo by Scott Atkins.

Pathogen: Undetermined

PNNL researchers are investigating individual viruses to better understand how they live and thrive on host cells. Pictured here is researcher Kristie Oxford harvesting a virus for global systems biology analyses (proteomics, metabolomics and lipidomics) after it has grown on host cells.

 

Terms of Use: Our images are freely and publicly available for use with the credit line, "Andrea Starr | Pacific Northwest National Laboratory"; Please use provided caption information for use in appropriate context.

Jerilyn Timlin serves as a principal investigator for the Algal Predator and Pathogen Signature Verification project. The project looks at exploring and exploiting the various detailed optical signatures that arise when the algae cultivation pond surface is monitored using Sandia’s optical spectroradiometric techniques. These techniques can differentiate algae growth and state of health and provide an early warning of the active presence of predators and pathogens in outdoor algal ponds.

 

In 2009, Jerilyn was presented by the National Institutes of Health (NIH) with a New Innovator Award to develop state-of-the-art imaging technology that can measure protein complex formation and protein networks.

 

Learn more at bit.ly/2n790Er.

 

Photo by Randy Montoya.

This image is excerpted from a U.S. GAO report:

www.gao.gov/products/GAO-21-426SP

 

Science & Tech Spotlight: Genomic Sequencing Of Infectious Pathogens

Pathogen: Undetermined

Pathogen: Cephaleuros parasiticus (green algae)

 

Read: www.ctahr.hawaii.edu/oc/freepubs/pdf/pd-43.pdf

Coagulase Negative Staphylococcus growing on ChromID CPS chromogenic agar. Isolate from a urine sample from a catheterised 45 year old male patient undergoing chemotherapy for leukaemia

Staphylococcus aureus on ChromID CPS chromogenic agar. Isolate from a urine sample from a 45 year old catheterised male awaiting surgery for a bladder stone.

Staphylococcus saprophyticus growing on ChromID CPS chromogenic agar. Isolate from a urine from a 21 year old pregnant female with proteinuria and a high urinary leucocyte count. Isolate appears very pale pink on this medium

Urine cultures on ChromID CPS - mixed culture, probably caused by a poorly taken specimen

 

Organism present Enterococcus species, Escherichia coli, Staphylococcus species, Streptococcus species (probable Viridans type)

Food safety pathogen Listeria monocytogenes isolated on agar from a food sample.

Pathogen: Coniothyrium concentricum

Pathogen: Undetermined

I had to move this ugly couch from the eighties to get a clear shot of this piece, but it was well worth the effort and possible exposure to pathogens.

Pathogen: Undetermined

Enterococcus faecalis on ChromID CPS chromogenic agar, Isolate from urine obtained from a 36 year old male diabetic patient with chronic renal failure.

Accession by Finland has triggered the entry into force of a key international measure for environmental protection that aims to stop the spread of potentially invasive aquatic species in ships’ ballast water.

 

The International Convention for the Control and Management of Ships' Ballast Water and Sediments (BWM Convention) will enter into force on 8 September 2017, marking a landmark step towards halting the spread of invasive aquatic species, which can cause havoc for local ecosystems, affect biodiversity and lead to substantial economic loss. Under the Convention’s terms, ships will be required to manage their ballast water to remove, render harmless, or avoid the uptake or discharge of aquatic organisms and pathogens within ballast water and sediments

 

“This is a truly significant milestone for the health of our planet,” said IMO Secretary-General Kitack Lim.

 

“The spread of invasive species has been recognized as one of the greatest threats to the ecological and the economic well-being of the planet. These species are causing enormous damage to biodiversity and the valuable natural riches of the earth upon which we depend. Invasive species also cause direct and indirect health effects and the damage to the environment is often irreversible,” he said.

 

He added, “The entry into force of the Ballast Water Management Convention will not only minimize the risk of invasions by alien species via ballast water, it will also provide a global level playing field for international shipping, providing clear and robust standards for the management of ballast water on ships.”

 

Her Excellency Mrs. Päivi Luostarinen Ambassador Extraordinary and Plenipotentiary, Permanent Representative of Finland to IMO, handed over the country’s instrument of acceptance to the Ballast Water Management Convention to IMO Secretary-General Lim on Thursday (8 September 2016).

 

The accession brings the combined tonnage of contracting States to the treaty to 35.1441%, with 52 contracting Parties. The convention stipulates that it will enter into force 12 months after ratification by a minimum of 30 States, representing 35% of world merchant shipping tonnage.

 

The BWM Convention was adopted in 2004 by the International Maritime Organization (IMO), the United Nations specialized agency with responsibility for developing global standards for ship safety and security and for the protection of the marine environment and the atmosphere from any harmful impacts of shipping.

 

The ballast water problem

Ballast water is routinely taken on by ships for stability and structural integrity. It can contain thousands of aquatic microbes, algae and animals, which are then carried across the world’s oceans and released into ecosystems where they are not native.

 

Untreated ballast water released at a ship’s destination could potentially introduce a new invasive aquatic species. Expanded ship trade and traffic volume over the last few decades has increased the likelihood of invasive species being released. Hundreds of invasions have already taken place, sometimes with devastating consequences for the local ecosystem.

 

The Ballast Water Management Convention will require all ships in international trade to manage their ballast water and sediments to certain standards, according to a ship-specific ballast water management plan. All ships will also have to carry a ballast water record book and an International Ballast Water Management Certificate. The ballast water performance standard will be phased in over a period of time. Most ships will need to install an on-board system to treat ballast water and eliminate unwanted organisms. More than 60 type-approved systems are already available.

 

IMO has been addressing the problem of invasive species in ships’ ballast water since the 1980s, when Member States experiencing particular problems brought their concerns to the attention of IMO's Marine Environment Protection Committee (MEPC). Guidelines to address the issue were adopted in 1991 and IMO then worked to develop the Ballast Water Management Convention, which was adopted in 2004.

 

IMO has worked extensively with the development of guidelines for the uniform implementation of the Convention and to address concerns of various stakeholders, such as with regards to the availability of ballast water management systems and their type approval and testing.

 

Shipboard ballast water management systems must be approved by national authorities, according to a process developed by IMO. Ballast water management systems have to be tested in a land-based facility and on board ships to prove that they meet the performance standard set out in the treaty. These could, for example, include systems which make use of filters and ultra violet light or electrochlorination.

 

Ballast water management systems which make use of active substances must undergo a strict approval procedure and be verified by IMO. There is a two-tier process, in order to ensure that the ballast water management system does not pose unreasonable risk to ship safety, human health and the aquatic environment.

 

GloBallast programme

Since 2000, the Global Environment Facility (GEF)-United Nations Development Program (UNDP)-IMO GloBallast Partnerships Project has been assisting developing countries to reduce the risk of aquatic bio-invasions through building the necessary capacity to implement the Convention. More than 70 countries have directly benefitted from the Project, which has received a number of international awards for its work.

 

GloBallast has recently been developing and running workshops on ballast water sampling and analysis to prepare States for the entry into force of the treaty. Free-to-access online learning tools have been made available, including an e-learning course on the operational aspects of ballast water management.

 

The GloBallast programme also engages with the private sector through the Global Industry Alliance (GIA) and GIA Fund, established with partners from major maritime companies.

 

Examples of invasive species

The North American comb jelly (Mnemiopsis leidyi) has travelled in ships' ballast water from the eastern seaboard of the Americas e.g. to the Black, Azov and Caspian Seas. It depletes zooplankton stocks; altering food web and ecosystem function. The species has contributed significantly to the collapse of Azov Sea, Black Sea and Caspian Sea fisheries in the 1990s and 2000s, with massive economic and social impact.

 

The Zebra mussel (Dreissena polymorpha) has been transported from the Black Sea to western and northern Europe, including Ireland and the Baltic Sea, and the eastern half of North America. Travelling in larval form in ballast water, on release it has rapid reproductive growth with no natural predators in North America. The mussel multiplies and fouls all available hard surfaces in mass numbers. Displacing native aquatic life, this species alters habitat, ecosystem and the food web and causes severe fouling problems on infrastructure and vessels. There have been high economic costs involved in unblocking water intake pipes, sluices and irrigation ditches.

 

The North Pacific seastar (Asterias amurensis) has been transported in ballast water from the northern Pacific to southern Australia. It reproduces in large numbers, reaching ‘plague’ proportions rapidly in invaded environments. This invasive species has caused significant economic loss as it feeds on shellfish, including commercially valuable scallop, oyster and clam species.

Pathogen: Undetermined

Pathogen: Asperisporium caricae (fungus)

U.S. Department of Agriculture (USDA) Agricultural Research Service (ARS) Research Entomologist Christopher (Chris) Geden, PhD., uses a vacuum device to gently collect adult flies for studies about the effect of artificial sweeteners and fungal pathogens on them at the ARS Center for Medical, Agricultural, and Veterinary Entomology, in Gainesville, FL, on February 24, 2021.

 

Geden works to find chemical insecticide alternatives to manage house fly populations. Here he is studying the use of fungal pathogens combined with artificial sweeteners. The sweetener attracts the flies and is lethal to them as well. Unlike sugar, the sweetener does not give them energy, just indigestion resulting in death by dehydration. At the same time, the fly is inoculated with fungal spores of a pathogen that will also kill them, and their cadavers will produce a new crop of spores that are spread by contact. Neither the sweetener nor the pathogen can harm humans.

House and stable flies are major pests of animal agriculture in the US and throughout the world. Management of these flies using insecticides can be problematic because the flies have developed resistance to many of the available products. The growing market for organic products creates additional demands for alternatives to chemical insecticides. Although their mode of action is not known, the artificial sweeteners xylitol and erythritol are toxic to adult flies of several species. Scientists at Northern Illinois University and ARS evaluated the effect of these sweeteners on the larvae of house flies and stable flies. These sweeteners appear to have potential as an inexpensive way to control flies without using conventional insecticides. Caption derived from ars.usda.gov/research/publications/publication/?seqNo115=356216

USDA Media by Lance Cheung.

Pathogen: Dasheen mosaic virus (DsMV)

 

Read: www.ctahr.hawaii.edu/oc/freepubs/pdf/PD-44.pdf

Introduction: Plants are a limitless gift of nature to humans and they possess very appreciative values and roles. They have stood the test of time in the life of man since creation. All over the world, they are hugely exploited for food, fuel, timber, medicine etc. The natural endowment of plants with numerous metabolites and bioactive compounds makes them good sources of therapeutic agents capable of replacing synthetic antibiotics; For example, Salversan and Penicillin are synthetic drugs formerly used for the treatment of Syphilis and Staphylococcus aureus infections, respectively, but which became less preferred because these pathogens developed resistance to the drugs.

 

Aim: This study was aimed at evaluating Euphorbia abyssinica (Desert Candle), a medicinal plant extensively used in folklore medicine among the Kendem people of South-west Cameroon for antibacterial activity and extracts analyzed for phytochemical composition.

 

Study Design: The completely randomized block design was used and data analyzed using of two way analysis of variance. Significant means were separated using Duncan’s New Multiple Range Test.

 

Place and Duration of Study: This study was carried out in the Department of Microbiology, University of Nigeria Nsukka, Enugu State, Nigeria, between April 2011 and August 2012.

 

Methodology: Extraction was done using absolute methanol, 50% methanol (in water) and water as solvents. Qualitative analysis methods were used to assay the phytochemical constituents. Agar-well diffusion, macro broth dilution and agar dilution and time-kill assay were the susceptibility test methods adapted.

 

Results: The phytochemical constituents detected were alkaloids, flavonoids, tannins, cardiac glycosides, carbohydrates and steroids, and saponins. The 50% methanol extract of the stem-bark was highly active against Staphyloccocus aureus, Escherichia coli, Salmonella typhi and Pseudomonas aeruginosa and compared favorably with the Gentamycin control drug. The inhibition zone diameters (IZDs) obtained with 50% methanol extract measured 23 mm for S. aureus and 19 mm for P. aeruginosa compared to 18 mm achieved with the absolute methanol extract for both S. aureus and P. aeniginosa. For the aqueous extract the overall IZD range of 10±1.60-13±2.16 mm. The susceptibility patterns obtained using both dilutions (agar and macro-broth) methods were similar to that obtained with the agar diffusion method above. S. aureus (with MIC, 10.93±1.00-; MBC, 25-mg/mL, agar dilution or MIC, 3.9±1.60 -, MBC, 12.5-mg/mL, macro broth dilution methods, respectively). It was considered to be the most significantly susceptible bacteria strain tested (significant mean value 3.933), while E. coli was the least susceptible (with MIC, 50±0.00-, MBC, 100-mg/mL, in the agar dilution; MIC, 25±0.00-, MBC, 50-mg/mL in the broth dilution and a significant mean value of 14.70). The stem-bark extracts was also significantly more active than the latex extracts P= .05 with significant mean values of 13.48 and 19.53 respectively. In the time-kill assay, all (100%) the organisms tested were killed by 50% methanol extract of E. abyssinica at concentrations equivalent to 1MIC- 4MIC.

 

Conclusion: E. abyssinica extracts showed considerable antibacterial activity against the bacterial species tested. These findings authenticate the folklore use of Euphorbia abyssinica for broad spectrum treatment of bacterial infections. The determination of the antimicrobial activity of Euphorbia abyssinica stem (bark and Latex extracts) extract included the 50% methanol, absolute methanol and aqueous extracts of these plant parts. The antimicrobial activity variously exhibited by the 50% methanol extracts of all the two plant parts tested, is significant. This is because it validates the popular traditional uses of dilute alcohol concoctions of medicinal plant preparations in ethno medicinal practice in south-West region of Cameroon. Secondly, the results indicated that these herbs used in traditional medicine have selective antimicrobial activities. Thus, the microorganisms which were susceptible to these extracts are those often associated with wound and ear infections, urinary and gastrointestinal tract infections as well as pyrexia of unknown origin. This explains the discriminate uses of these plants in the treatment of particular ailments. These findings provide evidence that E. abyssinica is a strong candidate in microgram concentrations while the plant extracts were effective in milligram concentrations. Therefore actual comparison between the control drugs and the extracts would await isolation, purification and determination of molar concentrations of the pure active ingredients of these plants extracts.

 

Author Details:

 

Jacqueline Ebob Tarh

Department of Biological Sciences, Cross River University of Technology, Calabar, Nigeria.

 

Christian Ukwuoma Iroegbu

Department of Biological Sciences, Cross River University of Technology, Calabar, Nigeria.

  

Read full article: bp.bookpi.org/index.php/bpi/catalog/view/50/405/435-1

View More: www.youtube.com/watch?v=43Q-A8UBkNM

U.S. Department of Agriculture (USDA) Agricultural Research Service (ARS) Research Entomologist Christopher (Chris) Geden, PhD., uses a vacuum device to gently collect adult flies for studies about the effect of artificial sweeteners and fungal pathogens on them at the ARS Center for Medical, Agricultural, and Veterinary Entomology, in Gainesville, FL, on February 24, 2021.

 

Geden works to find chemical insecticide alternatives to manage house fly populations. Here he is studying the use of fungal pathogens combined with artificial sweeteners. The sweetener attracts the flies and is lethal to them as well. Unlike sugar, the sweetener does not give them energy, just indigestion resulting in death by dehydration. At the same time, the fly is inoculated with fungal spores of a pathogen that will also kill them, and their cadavers will produce a new crop of spores that are spread by contact. Neither the sweetener nor the pathogen can harm humans.

House and stable flies are major pests of animal agriculture in the US and throughout the world. Management of these flies using insecticides can be problematic because the flies have developed resistance to many of the available products. The growing market for organic products creates additional demands for alternatives to chemical insecticides. Although their mode of action is not known, the artificial sweeteners xylitol and erythritol are toxic to adult flies of several species. Scientists at Northern Illinois University and ARS evaluated the effect of these sweeteners on the larvae of house flies and stable flies. These sweeteners appear to have potential as an inexpensive way to control flies without using conventional insecticides. Caption derived from ars.usda.gov/research/publications/publication/?seqNo115=356216

USDA Media by Lance Cheung.

Pathogen: Fig mosaic virus | Photograph by Ann Verga

Various fungal plant pathogen genera can rot strawberry fruit, including Penicillium, Botrytis and Rhizopus.

MSU Department of Microbiology and Molecular Genetics professor Chris Waters.

Photo caption: Freshman Sam Lemel looks for signs of hops downy mildew during a visit to the hops field at the Mountain Horticultural Crops Research and Extension Center in Mills River. Lemel and his partner Bryce Spradlin worked this semester to design a rapid test for the pathogen.

 

The TIME Honors Science Research Course is an intensive, inquiry-based school-day course. Students learn about the process of science as they conduct original scientific research into topics of their own choosing. They are supported by both teacher and scientist mentors as they choose a topic of interest, develop a testable question, design a procedure, collect and analyze data and present their findings.

 

All Transylvania County Schools high school students (rising 9-12 graders) are eligible to apply for the course. Participants will be chosen through an application process that began in January of 2015, with application deadlines beginning Jan. 30. Course enrollment will be limited. Students will be chosen by an independent selection committee based on their demonstrated interest in science, potential for success in scientific research, and commitment to all components of the course.

 

Students chosen in 2015 will attend a trip to observe state research competitions in March and a summer field study week prior to the course. The school-day portion of the course will be held during the fall of 2015 in Brevard High School's Science Research Laboratory. Students will enter their work in one or more science competitions during the winter of 2016.

 

Why apply for the TIME Honors Science Research Course? Students benefit from doing research projects because they see how science applies to their own lives and community. They learn more about the process of science and what scientists do as they act as co-learners with teachers, scientists and other students. They discover new careers in science. While conducting research projects, students develop independence-no one is telling them exactly what to do or how to do it. They learn how to break down a complex, long-term project into manageable pieces, develop a plan of action, and follow it through. As they conclude their projects, students learn how to communicate their results clearly and persuasively to a variety of audiences as they contribute to the bank of scientific knowledge with their findings.

 

Students who have conducted long-term research projects are more competitive as they apply for college and scholarships. Top colleges want students who can write as well as possess analytical skills, creativity and a multidisciplinary perspective. Most of all they want people with a capacity for continuous innovation. These are skills gained from conducting original research. Doing a science project and participating in a competition can give students the opportunity to meet and spend time with others from around the world who have similar interests while competing for significant scholarships, travel, monetary awards and other prizes.

 

Current TIME students have recently completed the following research projects: Testing for the presence of estrogen-like compounds In Stevia rebaudiana (Cameron McCathern, Erin Smith and Sam Farrar); Electroantennogram response of Megacopta cribraria to chemical components in its defensive secretion (Abby Williams and Carly Onnink); Evaluation of honeybee health in Transylvania County: An assessment of Varroa destructor and Nosema levels (Ingrid Findlay, Aaron Neumann, and Hannah Lemel); Isolation, identification and screening of local wood rot fungi for the production of lignin-degrading enzymes (Hannah Field and Ryan Holland); Agrobacterium-mediated stable transformation of Coleus X hybridus plants using the floral dip method and B-glucuronidase (GUS) gene as a reporter system (Carver Nichols); Adapting the LAMP assay and culturing methods for hops downy mildew, Pseudoronospora humuli (Sam Lemel and Bryce Spradlin); The effect of antibiotics on the mortality of the hemlock woolly adelgid, Adelges tsugae (Allison Reece and Lauren DuBreuil); Evaluation of VOC producing Diaporthe species for enzyme production (Joe Roberts, Lauren Tooley and Eliza Witherspoon); Identifica-tion and heavy metal remediation potential of fungi isolated from Duke Energy's 1964 Asheville coal ash pond (Ryulee Park and Aidan Spradlin); and studies on the walnut twig beetle (Pityophthorus juglandis) and its association with Geosmithia morbida (Crista Cali and Sarah Branagan).

 

Current TIME students would like to thank all who have helped with their research during the year including students, teachers, administration, parents and numerous scientists and community volunteers. Thanks go to 2014 TIME volunteers: Ken Chepenik, Don Wauchope, Paul Sisco, Jeanine Davis, Kelly Gaskill, Laurie Moorhead, Chuck McGrady, Page Lemel, Craig DeBrew, Ervin Kovacs, Chris Cali, Pat Montgomery, Tammy Bellefeuil, Adam DeWitt, Brian Heath, Amy Kinsella, Kelly Oten, Bryan Dubois, David Williams, Cindy Carpenter, Lisa Smith, Eric Caldwell, Jay Case, Andy VonCanon, Dan Harris, Danny Fender, Paul Sisco, Scott Pryor, Rene Timmons, Nancy Knights, Sheila and Marvin Holland, George Logsdon, Ed Burdette, Mary Ann Mickewitz, Crawford and Jeanette Lowe, Allen Frost, Ora Wells, Randy Oliver, Coby Schal, Bart Renner, Harriett Walls, Kaitlin McCreery, Gordon Riedesel, Summer Cortinas, Bruce Roberts, Roger Frisbee and Wes Freund. Special thanks go to Dr. Kent Wilcox and Mary Arnaudin, without whose help, guidance, and actions the class could not have been possible!

 

Funds for the TIME Science Research Course are provided in part by a grant from the Burroughs Wellcome Fund in addition to support from Transylvania County Schools and NC Cooperative Extension. Special thanks go to a growing group of community donors: the American Association of University Women, Pisgah Forest Rotary Club, PharmAgra, The Robertson Foundation, Merrill Well and Pump Company, Environmental Quality Institute, Roger Frisbee, June Litchfield, Peter Chaveas, Steve and Mary Beth Whitmire, Newell and Mary Witherspoon, Ed Buckbee, Kristine and John Candler, NC BioNetwork Labs, Kent Wilcox, Ken Chepenik, Ann Farash and Paul Onnink, Bee Cool Bee Supply and Pat Montgomery.

 

For more information, to apply for the research course, or to indicate an interest in volunteering or donating to the program, visit time4realscience.org.

 

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bug on the wall