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Bacteria
Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among the first life forms to appear on Earth, and are present in most of its habitats. Bacteria inhabit soil, water, acidic hot springs, radioactive waste, and the deep biosphere of Earth's crust. Bacteria are vital in many stages of the nutrient cycle by recycling nutrients such as the fixation of nitrogen from the atmosphere. The nutrient cycle includes the decomposition of dead bodies; bacteria are responsible for the putrefaction stage in this process. In the biological communities surrounding hydrothermal vents and cold seeps, extremophile bacteria provide the nutrients needed to sustain life by converting dissolved compounds, such as hydrogen sulphide and methane, to energy. Bacteria also live in symbiotic and parasitic re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pseudomonadota
Pseudomonadota (synonym Proteobacteria) is a major phylum of Gram-negative bacteria. The renaming of phyla in 2021 remains controversial among microbiologists, many of whom continue to use the earlier names of long standing in the literature. The phylum Proteobacteria includes a wide variety of pathogenic genera, such as '' Escherichia'', '' Salmonella'', '' Vibrio'', '' Yersinia'', '' Legionella'', and many others.Slonczewski JL, Foster JW, Foster E. Microbiology: An Evolving Science 5th Ed. WW Norton & Company; 2020. Others are free-living (non parasitic) and include many of the bacteria responsible for nitrogen fixation. Carl Woese established this grouping in 1987, calling it informally the "purple bacteria and their relatives". Because of the great diversity of forms found in this group, it was later informally named Proteobacteria, after Proteus, a Greek god of the sea capable of assuming many different shapes (not after the Proteobacteria genus ''Proteus''). In 2021 the In ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alphaproteobacteria
Alphaproteobacteria is a class of bacteria in the phylum Pseudomonadota (formerly Proteobacteria). The Magnetococcales and Mariprofundales are considered basal or sister to the Alphaproteobacteria. The Alphaproteobacteria are highly diverse and possess few commonalities, but nevertheless share a common ancestor. Like all ''Proteobacteria'', its members are gram-negative and some of its intracellular parasitic members lack peptidoglycan and are consequently gram variable. Characteristics The Alphaproteobacteria are a diverse taxon and comprises several phototrophic genera, several genera metabolising C1-compounds (''e.g.'', ''Methylobacterium'' spp.), symbionts of plants (''e.g.'', '' Rhizobium'' spp.), endosymbionts of arthropods (''Wolbachia'') and intracellular pathogens (''e.g. Rickettsia''). Moreover, the class is sister to the protomitochondrion, the bacterium that was engulfed by the eukaryotic ancestor and gave rise to the mitochondria, which are organelles in eukaryoti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rickettsiales
The Rickettsiales, informally called rickettsias, are an order of small Alphaproteobacteria. They are obligate intracellular parasites, and some are notable pathogens, including '' Rickettsia'', which causes a variety of diseases in humans, and '' Ehrlichia'', which causes diseases in livestock. Another genus of well-known Rickettsiales is the '' Wolbachia'', which infect about two-thirds of all arthropods and nearly all filarial nematodes. Genetic studies support the endosymbiotic theory according to which mitochondria and related organelles developed from members of this group.Thomas S. (2016). Rickettsiales:Biology, Molecular Biology, Epidemiology, and Vaccine Development. pp.529. Springer• The Rickettsiales are difficult to culture, as they rely on living eukaryotic host cells for their survival. Rickettsiales phylogeny The Rickettsiales further consist of three known families, the Rickettsiaceae, the Midichloriaceae, and the Ehrlichiaceae. Most studies also support ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ehrlichiaceae
The Ehrlichiaceae are a family of bacteria, included in the order Rickettsiales The Rickettsiales, informally called rickettsias, are an order of small Alphaproteobacteria. They are obligate intracellular parasites, and some are notable pathogens, including '' Rickettsia'', which causes a variety of diseases in humans, and .... References External links * Rickettsiales Bacteria families {{alphaproteobacteria-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anaplasma
''Anaplasma'' is a genus of bacteria of the alphaproteobacterial order Rickettsiales, family Anaplasmataceae. ''Anaplasma'' species reside in host blood cells and lead to the disease anaplasmosis. The disease most commonly occurs in areas where competent tick vectors are indigenous, including tropical and semitropical areas of the world for intraerythrocytic ''Anaplasma'' spp.Anaplasmas reviewed and published by , accessed 10 October 2011. ''Anaplasma'' species are biologically transmitted by Ixodes deer-tick vectors, and the prototypical species, ''A. marginale,'' can be mechanically transmitted by biting flies and iatrogenically with blood-contam ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
