|
Aspergillus Versicolor
''Aspergillus versicolor'' is a slow-growing filamentous fungus commonly found in damp indoor environments and on food products. It has a characteristic musty odor associated with moldy homes and is a major producer of the hepatotoxic and carcinogenic mycotoxin sterigmatocystin. Like other ''Aspergillus'' species, ''A. versicolor'' is an eye, nose, and throat irritant. Taxonomy The fungus was first described by Jean-Paul Vuillemin in 1903 under the name ''Sterigmatocystis versicolor'', and was later moved to the genus ''Aspergillus'' by Carlo Tiraboschi in 1908. Presently, the genus ''Sterigmatocystis'' is obsolete. Ecology ''Aspergillus versicolor'' is a highly ubiquitous species commonly isolated from soil, plant debris, marine environments, and indoor air environments. It is among the most common of indoor Mold (fungus), molds, often reported in dust and in water-damaged building materials, such as wallboards, insulation, textiles, ceiling tiles, and manufactured wood. ''Asp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fungus
A fungus ( : 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 a kingdom, separately from the other eukaryotic kingdoms, which by one traditional classification include Plantae, Animalia, 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 f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hemicellulose
A hemicellulose (also known as polyose) is one of a number of heteropolymer, heteropolymers (matrix polysaccharides), such as arabinoxylans, present along with cellulose in almost all embryophyte, terrestrial plant cell walls.Scheller HV, Ulvskov Hemicelluloses.// Annu Rev Plant Biol. 2010;61:263-89. doi: 10.1146/annurev-arplant-042809-112315. Cellulose is crystalline, strong, and resistant to hydrolysis. Hemicelluloses are branched, shorter in length than cellulose, and also show a propensity to crystallize. They can be hydrolyzed by dilute acid or Base (chemistry), base as well as a myriad of Cellulase, hemicellulase enzymes. Composition Diverse kinds of hemicelluloses are known. Important examples include xylan, glucuronoxylan, arabinoxylan, glucomannan, and xyloglucan. Hemicelluloses are polysaccharides often associated with cellulose, but with distinct compositions and structures. Whereas cellulose is derived exclusively from glucose, hemicelluloses are composed of diverse ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Onychomycosis
Onychomycosis, also known as tinea unguium, is a fungal infection of the nail. Symptoms may include white or yellow nail discoloration, thickening of the nail, and separation of the nail from the nail bed. Toenails or fingernails may be affected, but it is more common for toenails. Complications may include cellulitis of the lower leg. A number of different types of fungus can cause onychomycosis, including dermatophytes and ''Fusarium''. Risk factors include athlete's foot, other nail diseases, exposure to someone with the condition, peripheral vascular disease, and poor immune function. The diagnosis is generally suspected based on the appearance and confirmed by laboratory testing. Onychomycosis does not necessarily require treatment. The antifungal medication terbinafine taken by mouth appears to be the most effective but is associated with liver problems. Trimming the affected nails when on treatment also appears useful. There is a ciclopirox-containing nail polish, but t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aspergillosis
Aspergillosis is a fungal infection of usually the lungs, caused by the genus ''Aspergillus'', a common mould that is breathed in frequently from the air around, but does not usually affect most people. It generally occurs in people with lung diseases such as asthma, cystic fibrosis or tuberculosis, or those who have had a stem cell or organ transplant, and those who cannot fight infection because of medications they take such as steroids and some cancer treatments. Rarely, it can affect skin. Aspergillosis occurs in humans, birds and other animals. Aspergillosis occurs in chronic or acute forms which are clinically very distinct. Most cases of acute aspergillosis occur in people with severely compromised immune systems, e.g. those undergoing bone marrow transplantation. Chronic colonization or infection can cause complications in people with underlying respiratory illnesses, such as asthma, cystic fibrosis, sarcoidosis, tuberculosis, or chronic obstructive pulmonary disease. Most ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aflatoxin B1
Aflatoxin B1 is an aflatoxin produced by ''Aspergillus flavus'' and '' A. parasiticus''. It is a very potent carcinogen with a TD50 3.2 μg/kg/day in rats. This carcinogenic potency varies across species with some, such as rats and monkeys, seemingly much more susceptible than others. Aflatoxin B1 is a common contaminant in a variety of foods including peanuts, cottonseed meal, corn, and other grains; as well as animal feeds. Aflatoxin B1 is considered the most toxic aflatoxin and it is highly implicated in hepatocellular carcinoma (HCC) in humans. In animals, aflatoxin B1 has also been shown to be mutagenic, teratogenic, and to cause immunosuppression. Several sampling and analytical methods including thin-layer chromatography (TLC), high-performance liquid chromatography (HPLC), mass spectrometry, and enzyme-linked immunosorbent assay (ELISA), among others, have been used to test for aflatoxin B1 contamination in foods. According to the Food and Agriculture Organization (FAO), t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbapenemase
Beta-lactamases, (β-lactamases) are enzymes () produced by bacteria that provide multi-resistance to beta-lactam antibiotics such as penicillins, cephalosporins, cephamycins, monobactams and carbapenems (ertapenem), although carbapenems are relatively resistant to beta-lactamase. Beta-lactamase provides antibiotic resistance by breaking the antibiotics' structure. These antibiotics all have a common element in their molecular structure: a four-atom ring known as a beta-lactam (β-lactam) ring. Through hydrolysis, the enzyme lactamase breaks the β-lactam ring open, deactivating the molecule's antibacterial properties. Beta-lactam antibiotics are typically used to target a broad spectrum of gram-positive and gram-negative bacteria. Beta-lactamases produced by gram-negative bacteria are usually secreted, especially when antibiotics are present in the environment. Structure The structure of a ''Streptomyces'' serine β-lactamase (SBLs) is given by . The alpha-beta fold ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antibiotic Resistance
Antimicrobial resistance (AMR) occurs when microbes evolve mechanisms that protect them from the effects of antimicrobials. All classes of microbes can evolve resistance. Fungi evolve antifungal resistance. Viruses evolve antiviral resistance. Protozoa evolve antiprotozoal resistance, and bacteria evolve antibiotic resistance. Those bacteria that are considered extensively drug resistant (XDR) or totally drug-resistant (TDR) are sometimes called "superbugs".A.-P. Magiorakos, A. Srinivasan, R. B. Carey, Y. Carmeli, M. E. Falagas, C. G. Giske, S. Harbarth, J. F. Hinndler ''et al''Multidrug-resistant, extensively drug-resistant and pandrug-resistant bacteria... Clinical Microbiology and Infection, Vol 8, Iss. 3 first published 27 July 2011 ia Wiley Online Library Retrieved 28 August 2020 Although antimicrobial resistance is a naturally-occurring process, it is often the result of improper usage of the drugs and management of the infections. Antibiotic resistance is a major subset ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aspergillomarasmine A
Aspergillomarasmine A is an polyamino acid naturally produced by the mold ''Aspergillus versicolor''. The substance has been reported to inhibit two antibiotic resistance carbapenemase proteins in bacteria, New Delhi metallo-beta-lactamase 1 (NDM-1) and Verona integron-encoded metallo-beta-lactamase (VIM-2), and make those antibiotic-resistant bacteria susceptible to antibiotics. Aspergillomarasmine A is toxic to leaves of barley and other plants, being termed as "Toxin C" when produced by ''Pyrenophora teres''. The molecule is a tetracarboxylic acid with four -COOH groups. One section of the molecule is the amino acid aspartic acid. This has two alanine molecules attached by substituting a hydrogen on the methyl group with a link to the amine group. Aspergillomarasmine B differs in that the last alanine is replaced by glycine. The crystalline substance was first isolated in 1956, but its name was given until 1965. In addition to ''Aspergillus versicolor'', aspergillomarasmine A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anthraquinones
''For the parent molecule 9,10-anthraquinone, see anthraquinone'' Anthraquinones (also known as anthraquinonoids) are a class of naturally occurring phenolic compounds based on the 9,10-anthraquinone skeleton. They are widely used industrially and occur naturally. Occurrence in plants : Natural pigments that are derivatives of anthraquinone are found, inter alia, in aloe latex, senna, rhubarb, and cascara buckthorn, fungi A fungus ( : 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 a kingdom, separately from ..., lichens, and some insects. A type II polyketide synthase is responsible for anthraquinone biosynthesis in the bacterium ''Photorhabdus luminescens''. Chorismate, formed by isochorismate synthase in the shikimate pathway, is a precursor of anthraquinones in ''Morinda citrifolia''. Tests for anthraquinones in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fellutamide
Fellutamides are tripeptide derivatives from '' Penicillium fellutanum'' and other fungi. They are potent proteasome inhibitor that stimulates nerve growth factor synthesis ''in vitro''. Fellutamides A and F were first isolated from ''Aspergillus versicolor''. Fellutamides C and D were first isolated from an undescribed '' Metulocladosporiella'' (Chaetothyriales). Fellutamide B strongly inhibits the growth of the tuberculosis-causing bacterium ''Mycobacterium tuberculosis''. Its biosynthetic pathway has been determined in the filamentous fungus ''Aspergillus nidulans ''Aspergillus nidulans'' (also called ''Emericella nidulans'' when referring to its sexual form, or teleomorph) is one of many species of filamentous fungi in the phylum Ascomycota. It has been an important research organism for studying eukaryo ...''. References Penicillium Tripeptides {{Protein-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sesquiterpenoid
Sesquiterpenes are a class of terpenes that consist of three isoprene units and often have the molecular formula C15H24. Like monoterpenes, sesquiterpenes may be cyclic or contain rings, including many unique combinations. Biochemical modifications such as oxidation or rearrangement produce the related sesquiterpenoids. Sesquiterpenes are found naturally in plants and insects, as semiochemicals, e.g. defensive agents or pheromones. Biosynthesis and examples The reaction of geranyl pyrophosphate with isopentenyl pyrophosphate results in the 15-carbon farnesyl pyrophosphate (FPP), which is an intermediate in the biosynthesis of sesquiterpenes such as farnesene. Cyclic sesquiterpenes are more common than cyclic monoterpenes because of the increased chain length and additional double bond in the sesquiterpene precursors. In addition to common six-membered ring systems such as the ones found in zingiberene and bisacurone, cyclization of one end of the chain to the other end can ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbon Catabolite Repression
Carbon catabolite repression, or simply catabolite repression, is an important part of global control system of various bacteria and other microorganisms. Catabolite repression allows microorganisms to adapt quickly to a preferred (rapidly metabolizable) carbon and energy source first. This is usually achieved through inhibition of synthesis of enzymes involved in catabolism of carbon sources other than the preferred one. The catabolite repression was first shown to be initiated by glucose and therefore sometimes referred to as the glucose effect. However, the term "glucose effect" is actually a misnomer since other carbon sources are known to induce catabolite repression. ''Escherichia coli'' Catabolite repression was extensively studied in ''Escherichia coli''. ''E. coli'' grows faster on glucose than on any other carbon source. For example, if ''E. coli'' is placed on an agar plate containing only glucose and lactose, the bacteria will use glucose first and lactose second. When g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
