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Black Yeast
“Black yeasts”, sometimes also black fungi, dematiaceous fungi, microcolonial fungi or meristematic fungi is a diverse group of slow-growing microfungi which reproduce mostly asexually (fungi imperfecti). Only few genera reproduce by budding cells, while in others hyphal or meristematic (isodiametric) reproduction is preponderant. Black yeasts share some distinctive characteristics, in particular a dark colouration ( melanisation) of their cell wall. Morphological plasticity, incrustation of the cell wall with melanins and presence of other protective substances like carotenoids and mycosporines represent passive physiological adaptations which enable black fungi to be highly resistant against environmental stresses. The term " polyextremotolerance" has been introduced to describe this phenotype, a good example of which is the species ''Aureobasidium pullulans''. Presence of 1,8-dihydroxynaphthalene melanin in the cell wall confers to the microfungi their characteristic oli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microfungi
Microfungi or micromycetes are fungi—eukaryotic organisms such as molds, mildews and rusts—which have microscopic spore-producing structures. They exhibit tube tip-growth and have cell walls composed of chitin, a polymer of ''N''-acetylglucosamine. Microfungi are a paraphyletic group, distinguished from macrofungi only by the absence of a large, multicellular fruiting body. They are ubiquitous in all terrestrial and freshwater and marine environments, and grow in plants, soil, water, insects, cattle rumens, hair, and skin. Most of the fungal body consists of microscopic threads, called hyphae, extending through the substrate in which it grows. The mycelia of microfungi produce spores that are carried by the air, spreading the fungus. Many microfungi species are benign, existing as soil saprotrophs, for example, largely unobserved by humans. Many thousands of microfungal species occur in lichens, forming symbiotic relationships with algae. Other microfungi, such as those of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dothideomycetes
Dothideomycetes is the largest and most diverse class of ascomycete fungi. It comprises 11 orders 90 families, 1300 genera and over 19,000 known species. Traditionally, most of its members were included in the loculoascomycetes, which is not part of the currently accepted classification. This indicates that several traditional morphological features in the class are not unique and DNA sequence comparisons are important to define the class. The designation loculoascomycetes was first proposed for all fungi which have ascolocular development. This type of development refers to the way in which the sexual structure, bearing the sexual spores (ascospores) forms. Dothideomycetes mostly produce flask-like structures referred to as pseudothecia, although other shape variations do exist (e.g. see structures found in Hysteriales). During ascolocular development pockets (locules) form first within the vegetative cells of the fungus and then all the subsequent structures form. These includ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Halotolerance
Halotolerance is the adaptation of living organisms to conditions of high salinity. Halotolerant species tend to live in areas such as hypersaline lakes, coastal dunes, saline deserts, salt marshes, and inland salt seas and springs. Halophiles are organisms that live in highly saline environments, and require the salinity to survive, while halotolerant organisms (belonging to different domains of life) can grow under saline conditions, but do not require elevated concentrations of salt for growth. Halophytes are salt-tolerant higher plants. Halotolerant microorganisms are of considerable biotechnological interest. Applications Fields of scientific research relevant to halotolerance include biochemistry, molecular biology, cell biology, physiology, ecology, and genetics. An understanding of halotolerance can be applicable to areas such as arid-zone agriculture, xeriscaping, aquaculture (of fish or algae), bioproduction of desirable compounds (such as phycobiliproteins or carotenoi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ionizing Radiation
Ionizing radiation (or ionising radiation), including nuclear radiation, consists of subatomic particles or electromagnetic waves that have sufficient energy to ionize atoms or molecules by detaching electrons from them. Some particles can travel up to 99% of the speed of light, and the electromagnetic waves are on the high-energy portion of the electromagnetic spectrum. Gamma rays, X-rays, and the higher energy ultraviolet part of the electromagnetic spectrum are ionizing radiation, whereas the lower energy ultraviolet, visible light, nearly all types of laser light, infrared, microwaves, and radio waves are non-ionizing radiation. The boundary between ionizing and non-ionizing radiation in the ultraviolet area is not sharply defined, as different molecules and atoms ionize at different energies. The energy of ionizing radiation starts between 10 electronvolts (eV) and 33 eV. Typical ionizing subatomic particles include alpha particles, beta particles, and neutrons. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biofiltration
Biofiltration is a pollution control technique using a bioreactor containing living material to capture and biologically degrade pollutants. Common uses include processing waste water, capturing harmful chemicals or silt from surface runoff, and microbiotic oxidation of contaminants in air. Industrial biofiltration can be classified as the process of utilizing biological oxidation to remove volatile organic compounds, odors, and hydrocarbons. Examples of biofiltration Examples of biofiltration include: * Bioswales, biostrips, biobags, bioscrubbers, Vermifilters and trickling filters * Constructed wetlands and natural wetlands * Slow sand filters * Treatment ponds * Green belts * Green walls * Riparian zones, riparian forests, bosques * Bivalve bioaccumulation Control of air pollution When applied to air filtration and purification, biofilters use microorganisms to remove air pollution. The air flows through a packed bed and the pollutant transfers into a thin biofilm on t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bioremediation
Bioremediation broadly refers to any process wherein a biological system (typically bacteria, microalgae, fungi, and plants), living or dead, is employed for removing environmental pollutants from air, water, soil, flue gasses, industrial effluents etc., in natural or artificial settings. The natural ability of organisms to adsorb, accumulate, and degrade common and emerging pollutants has attracted the use of biological resources in treatment of contaminated environment. In comparison to conventional physicochemical treatment methods bioremediation may offer considerable advantages as it aims to be sustainable, eco-friendly, cheap, and scalable. Most bioremediation is inadvertent, involving native organisms. Research on bioremediation is heavily focused on stimulating the process by inoculation of a polluted site with organisms or supplying nutrients to promote the growth. In principle, bioremediation could be used to reduce the impact of byproducts created from anthropogenic acti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astrobiology
Astrobiology, and the related field of exobiology, is an interdisciplinary scientific field that studies the origins, early evolution, distribution, and future of life in the universe. Astrobiology is the multidisciplinary field that investigates the deterministic conditions and contingent events with which life arises, distributes, and evolves in the universe. Astrobiology makes use of molecular biology, biophysics, biochemistry, chemistry, astronomy, physical cosmology, exoplanetology, geology, paleontology, and ichnology to investigate the possibility of life on other worlds and help recognize biospheres that might be different from that on Earth. The origin and early evolution of life is an inseparable part of the discipline of astrobiology. Astrobiology concerns itself with interpretation of existing scientific data, and although speculation is entertained to give context, astrobiology concerns itself primarily with hypotheses that fit firmly into existing scientific ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hortaea Werneckii
''Hortaea werneckii'' is a species of yeast in the family Teratosphaeriaceae. It is a black yeast that is investigated for its remarkable halotolerance. While the addition of salt to the medium is not required for its cultivation, ''H. werneckii'' can grow in close to saturated NaCl solutions. To emphasize this unusually wide adaptability, and to distinguish'' H. werneckii'' from other halotolerant fungi, which have lower maximum salinity limits, some authors describe ''H. werneckii'' as "extremely halotolerant". Several salt-tolerance mechanisms of ''H. werneckii ''have been studied on molecular level. For example, it is known that its major compatible solutes are glycerol, erythritol, arabitol, and mannitol; melanin accumulation of the cell wall aids in retention of at least glycerol inside of the cell. Several components of the high osmolarity glycerol (HOG) signalling pathway (which controls responses to osmotic shock) have been studied in detail and some seem t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phototrophs
Phototrophs () are organisms that carry out photon capture to produce complex organic compounds (e.g. carbohydrates) and acquire energy. They use the energy from light to carry out various cellular metabolic processes. It is a common misconception that phototrophs are obligatorily photosynthetic. Many, but not all, phototrophs often photosynthesize: they anabolically convert carbon dioxide into organic material to be utilized structurally, functionally, or as a source for later catabolic processes (e.g. in the form of starches, sugars and fats). All phototrophs either use electron transport chains or direct proton pumping to establish an electrochemical gradient which is utilized by ATP synthase, to provide the molecular energy currency for the cell. Phototrophs can be either autotrophs or heterotrophs. If their electron and hydrogen donors are inorganic compounds (e.g. , as in some purple sulfur bacteria, or , as in some green sulfur bacteria) they can be also called lithotrop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lichens
A lichen ( , ) is a composite organism that arises from algae or cyanobacteria living among hypha, filaments of multiple fungus, fungi species in a mutualism (biology), mutualistic relationship.Introduction to Lichens – An Alliance between Kingdoms . University of California Museum of Paleontology. Lichens have properties different from those of their component organisms. They come in many colors, sizes, and forms and are sometimes plant-like, but are not plants. They may have tiny, leafless branches (fruticose); flat leaf-like structures (foliose); grow crust-like, adhering tightly to a surface (substrate) like a thick coat of paint (crustose); have a powder-like appearance (Leprose lichen, leprose); or other growth forms. A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Exophiala Dermatitidis
''Exophiala dermatitidis'' is a thermophilic black yeast, and a member of the Herpotrichiellaceae. While the species is only found at low abundance in nature, metabolically active strains are commonly isolated in saunas, steam baths, and dish washers. ''Exophiala dermatitidis'' only rarely causes infection in humans, however cases have been reported around the world. In East Asia, the species has caused lethal brain infections in young and otherwise healthy individuals. The fungus has been known to cause cutaneous and subcutaneous phaeohyphomycosis, and as a lung colonist in people with cystic fibrosis in Europe. In 2002, an outbreak of systemic ''E. dermatitidis'' infection occurred in women who had received contaminated steroid injections at North Carolina hospitals. Appearance and general description ''Exophiala dermatitidis'' forms slow growing, brown or black colonies. As is common amongst black yeasts, ''E. dermatitidis'' is an anamorphic fungus with multiple conidial fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
