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Microbial Metabolism
Microbial metabolism is the means by which a microbe obtains the energy and nutrients (e.g. carbon) it needs to live and reproduce. Microbes use many different types of metabolic strategies and species can often be differentiated from each other based on metabolic characteristics. The specific metabolic properties of a microbe are the major factors in determining that microbe's ecological niche, and often allow for that microbe to be useful in industrial processes or responsible for biogeochemical cycles. Types All microbial metabolisms can be arranged according to three principles: 1. How the organism obtains carbon for synthesizing cell mass:Morris, J. et al. (2019). "Biology: How Life Works", 3rd edition, W. H. Freeman. * autotrophic – carbon is obtained from carbon dioxide () * heterotrophic – carbon is obtained from organic compounds * mixotrophic – carbon is obtained from both organic compounds and by fixing carbon dioxide 2. How the organism obtains reducing e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microorganism
A microorganism, or microbe,, ''mikros'', "small") and ''organism'' from the el, ὀργανισμός, ''organismós'', "organism"). It is usually written as a single word but is sometimes hyphenated (''micro-organism''), especially in older texts. The informal synonym ''microbe'' () comes from μικρός, mikrós, "small" and βίος, bíos, "life". is an organism of microscopic size, which may exist in its single-celled form or as a colony of cells. The possible existence of unseen microbial life was suspected from ancient times, such as in Jain scriptures from sixth century BC India. The scientific study of microorganisms began with their observation under the microscope in the 1670s by Anton van Leeuwenhoek. In the 1850s, Louis Pasteur found that microorganisms caused food spoilage, debunking the theory of spontaneous generation. In the 1880s, Robert Koch discovered that microorganisms caused the diseases tuberculosis, cholera, diphtheria, and anthrax. Because mi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemotroph
A Chemotroph is an organism that obtains energy by the oxidation of electron donors in their environments. These molecules can be organic ( chemoorganotrophs) or inorganic (chemolithotrophs). The chemotroph designation is in contrast to phototrophs, which use photons. Chemotrophs can be either autotrophic or heterotrophic. Chemotrophs can be found in areas where electron donors are present in high concentration, for instance around hydrothermal vents. Chemoautotroph Chemoautotrophs, in addition to deriving energy from chemical reactions, synthesize all necessary organic compounds from carbon dioxide. Chemoautotrophs can use inorganic energy sources such as hydrogen sulfide, elemental sulfur, ferrous iron, molecular hydrogen, and ammonia or organic sources to produce energy. Most chemoautotrophs are extremophiles, bacteria or archaea that live in hostile environments (such as deep sea vents) and are the primary producers in such ecosystems. Chemoautotrophs generally fall into s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sulfate-reducing Bacteria
Sulfate-reducing microorganisms (SRM) or sulfate-reducing prokaryotes (SRP) are a group composed of sulfate-reducing bacteria (SRB) and sulfate-reducing archaea (SRA), both of which can perform anaerobic respiration utilizing sulfate () as terminal electron acceptor, reducing it to hydrogen sulfide (H2S). Therefore, these sulfidogenic microorganisms "breathe" sulfate rather than molecular oxygen (O2), which is the terminal electron acceptor reduced to water (H2O) in aerobic respiration. Most sulfate-reducing microorganisms can also reduce some other oxidized inorganic sulfur compounds, such as sulfite (), dithionite (), thiosulfate (), trithionate (), tetrathionate (), elemental sulfur (S8), and polysulfides (). Depending on the context, "sulfate-reducing microorganisms" can be used in a broader sense (including all species that can reduce any of these sulfur compounds) or in a narrower sense (including only species that reduce sulfate, and excluding strict thiosulfate and sulfu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wolinella
The genus ''Wolinella'' is a member of the Campylobacterales order of Bacteria. The order Campylobacterales includes human pathogens such as ''Helicobacter pylori'' and ''Campylobacter jejuni''. Strains The only publicly available strain of ''Wolinella'' is '' Wolinella succinogenes'' DSM 1740 (ATCC 29543). The original isolation of this organism was done by M. J. Wolin, E. A. Wolin and N. J. Jacobs at the University of Illinois. This original isolation was done from bovine rumen fluid and was somewhat serendipitous as the researchers were intending to isolate methanogenic organisms. This bacterium was originally classified as ''Vibrio succinogenes'', but was reclassified in 1981 to ''Wolinella succinogenes'' by A. C. R. Tanner ''et al''. Strains of ''Wolinella'' have been isolated from feline and canine oral cavities. Only one strain is currently published with ''Candidatus'' status: ''Candidatus Wolinella africanus''. This strain was isolated from the upper digestive tracts of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nitrobacter
''Nitrobacter'' is a genus comprising rod-shaped, gram-negative, and chemoautotrophic bacteria. The name ''Nitrobacter'' derives from the Latin neuter gender noun ''nitrum, nitri'', alkalis; the Ancient Greek noun βακτηρία'','' βακτηρίᾱς'','' rod. They are non-motile and reproduce via budding or binary fission. ''Nitrobacter'' cells are obligate aerobes and have a doubling time of about 13 hours. ''Nitrobacter'' play an important role in the nitrogen cycle by oxidizing nitrite into nitrate in soil and marine systems. Unlike plants, where electron transfer in photosynthesis provides the energy for carbon fixation, ''Nitrobacter'' uses energy from the oxidation of nitrite ions, NO2−, into nitrate ions, NO3−, to fulfill their energy needs. ''Nitrobacter'' fix carbon dioxide via the Calvin cycle for their carbon requirements. ''Nitrobacter'' belongs to the Alphaproteobacteria class of the Pseudomonadota. Morphology and characteristics ''Nitrobacter'' are gr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beggiatoa
''Beggiatoa'' is a genus of ''Gammaproteobacteria'' belonging the order ''Thiotrichales,'' in the ''Pseudomonadota'' phylum. This genus was one of the first bacteria discovered by Ukrainian botanist Sergei Sergei Winogradsky, Winogradsky. During his research in Anton de Bary's laboratory of botany in 1887, he found that ''Beggiatoa'' oxidized hydrogen sulfide (H2S) as energy source, forming intracellular sulfur droplets, oxygen is the terminal electron acceptor and CO², CO2 is used as carbon source. Winogradsky named it in honor of the Italian doctor and botanist Francesco Secondo Beggiato (1806 - 1883), from Venice. Winogradsky referred to this form of metabolism as "inorgoxidation" (oxidation of inorganic compounds), today called chemolithotrophy. These organisms live in sulfur-rich environments such as soil, both marine and freshwater, in the deep sea hydrothermal vents and in polluted marine environments. The finding represented the first discovery of lithotr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrogenophilaceae
The Hydrogenophilaceae are a family of the Hydrogenophilalia, with two genera – '' Hydrogenophilus'' and '' Tepidiphilus''. Like all ''Pseudomonadota'', they are Gram-negative. All known species are thermophilic, growing around 50 °C and using molecular hydrogen or organic molecules as their source of electrons to support growth - some species are autotrophs. The genus ''Thiobacillus'' was previously considered to be a member in this family but was reclassified into the order ''Nitrosomonadales'' at the same time that the ''Hydrogenophilales'' were removed from the ''Betaproteobacteria'' and the class ''Hydrogenophilalia'' was formed. '' Hydrogenophilus thermoluteolus'' is a facultative chemolithoautotroph originally isolated from a hot spring; however, it was detected 2004 in ice core samples retrieved from a depth around 3 km within the ice covering Lake Vostok in Antarctica Antarctica () is Earth's southernmost and least-populated continent. Situated alm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chloroflexus
Chloroflexales is an order of bacteria in the class Chloroflexia. Taxonomy The currently accepted taxonomy is based on the List of Prokaryotic names with Standing in Nomenclature (LPSN) and National Center for Biotechnology Information (NCBI). * Suborder Roseiflexineae Gupta et al. 2013 ** Family Roseiflexaceae Gupta et al. 2013 Kouleotrichaceae" Mehrshad et al. 2018*** Genus "'' Kouleothrix''" Kohno et al. 2002 *** Genus '' Heliothrix'' Pierson et al. 1986 *** Genus ''Roseiflexus'' Hanada et al. 2002 * Suborder Chloroflexineae Gupta et al. 2013 ** Family Chloroflexaceae Gupta et al. 2013 *** Genus ''Candidatus'' Chloranaerofilum Thiel et al. 2016 *** Genus ''Chloroflexus'' Pierson & Castenholz 1974 ''Chlorocrinis''"">Chlorocrinis.html" ;"title="''Chlorocrinis">''Chlorocrinis''"** Family Oscillochloridaceae Gupta et al. 2013 *** Genus ''Candidatus'' Chloroploca Gorlenko et al. 2014 *** Genus ''Chloronema'' ♪ Dubinina & Gorlenko 1975 *** Genus ''Oscillochloris'' Gorlenko & ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chromatiaceae
The Chromatiaceae are one of the two families of purple sulfur bacteria, together with the Ectothiorhodospiraceae. They belong to the order Chromatiales of the class Gammaproteobacteria, which is composed by unicellular Gram-negative organisms. Most of the species are photolithoautotrophs and conduct an anoxygenic photosynthesis, but there are also representatives capable of growing under dark and/or microaerobic conditions as either chemolithoautotrophs or chemoorganoheterotrophs. Both Ectothiorhodospiraceae and Chromatiaceae bacteria produce elemental sulfur globules, the difference is that in the second case they are stored inside the cells rather than outside. Sulfur is an intermediate in the oxidization of sulfide, which is ultimately converted into sulfate, and may serve as a reserve. History of classification Although purple sulfur bacteria have been known for some time, the difficulty in cultivating these microorganisms in the laboratory has made that few scientific d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyanobacteria
Cyanobacteria (), also known as Cyanophyta, are a phylum of gram-negative bacteria that obtain energy via photosynthesis. The name ''cyanobacteria'' refers to their color (), which similarly forms the basis of cyanobacteria's common name, blue-green algae, although they are not usually scientifically classified as algae. They appear to have originated in a freshwater or terrestrial environment. Sericytochromatia, the proposed name of the paraphyletic and most basal group, is the ancestor of both the non-photosynthetic group Melainabacteria and the photosynthetic cyanobacteria, also called Oxyphotobacteria. Cyanobacteria use photosynthetic pigments, such as carotenoids, phycobilins, and various forms of chlorophyll, which absorb energy from light. Unlike heterotrophic prokaryotes, cyanobacteria have internal membranes. These are flattened sacs called thylakoids where photosynthesis is performed. Phototrophic eukaryotes such as green plants perform photosynthesis in plast ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Knallgas-bacteria
Hydrogen-oxidizing bacteria are a group of facultative Autotroph, autotrophs that can use hydrogen as an electron donor. They can be divided into Aerobic organism, aerobes and Anaerobic organism, anaerobes. The former use hydrogen as an electron donor and oxygen as an acceptor while the latter use sulphate or nitrogen dioxide as electron acceptors. Species of both types have been isolated from a variety of environments, including fresh waters, sediments, soils, activated sludge, hot springs, hydrothermal vents and percolating water. These bacteria are able to exploit the special properties of molecular hydrogen (for instance redox potential and diffusion coefficient) thanks to the presence of Hydrogenase, hydrogenases. The aerobic hydrogen-oxidizing bacteria are facultative autotrophs, but they can also have Mixotroph, mixotrophic or completely heterotrophic growth. Most of them show greater growth on organic substrates. The use of hydrogen as an electron donor coupled with the abili ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
