|
Bacillota
The Bacillota (synonym Firmicutes) are a phylum of bacteria, most of which have Gram-positive cell wall structure. They have round cells, called cocci (singular coccus), or rod-like forms (bacillus). A few Bacillota, such as '' Megasphaera'', '' Pectinatus'', '' Selenomonas'', and '' Zymophilus'' from the class Negativicutes, have a porous pseudo-outer membrane that causes them to stain Gram-negative. Many Bacillota produce endospores, which are resistant to desiccation and can survive extreme conditions. They are found in various environments, and the group includes some notable pathogens. Those in one family, the Heliobacteria, produce energy through anoxygenic photosynthesis. Bacillota play an important role in beer, wine, and cider spoilage. Taxonomy The renaming of phyla such as Firmicutes in 2021 remains controversial among microbiologists, many of whom continue to use the earlier names of long standing in the literature. The name "Firmicutes" was derived from the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clostridia
The Clostridia are a highly polyphyletic class of Bacillota, including '' Clostridium'' and other similar genera. They are distinguished from the Bacilli by lacking aerobic respiration. They are obligate anaerobes and oxygen is toxic to them. Species of the class Clostridia are often but not always Gram-positive (see '' Halanaerobium'') and have the ability to form spores. Studies show they are not a monophyletic group, and their relationships are not entirely certain. Currently, most are placed in a single order called Clostridiales, but this is not a natural group and is likely to be redefined in the future. Most species of the genus ''Clostridium'' are saprophytic organisms that ferment plant polysaccharides and are found in many places in the environment, most notably the soil. However, the genus does contain some human pathogens (outlined below). The toxins produced by certain members of the genus ''Clostridium'' are among the most dangerous known. Examples are tetan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gram-positive Bacteria
In bacteriology, gram-positive bacteria are bacteria that give a positive result in the Gram stain test, which is traditionally used to quickly classify bacteria into two broad categories according to their type of cell wall. The Gram stain is used by microbiologists to place bacteria into two main categories, gram-positive (+) and gram-negative (−). Gram-positive bacteria have a thick layer of peptidoglycan within the cell wall, and gram-negative bacteria have a thin layer of peptidoglycan. Gram-positive bacteria retain the crystal violet stain used in the test, resulting in a purple color when observed through an optical microscope. The thick layer of peptidoglycan in the bacterial cell wall retains the stain after it has been fixed in place by iodine. During the decolorization step, the decolorizer removes crystal violet from all other cells. Conversely, gram-negative bacteria cannot retain the violet stain after the decolorization step; alcohol used in this stage ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gram-negative Bacteria
Gram-negative bacteria are bacteria that, unlike gram-positive bacteria, do not retain the Crystal violet, crystal violet stain used in the Gram staining method of bacterial differentiation. Their defining characteristic is that their cell envelope consists of a thin peptidoglycan gram-negative cell wall, cell wall sandwiched between an inner (Cytoplasm, cytoplasmic) Cell membrane, membrane and an Bacterial outer membrane, outer membrane. These bacteria are found in all environments that support life on Earth. Within this category, notable species include the model organism ''Escherichia coli'', along with various pathogenic bacteria, such as ''Pseudomonas aeruginosa'', ''Chlamydia trachomatis'', and ''Yersinia pestis''. They pose significant challenges in the medical field due to their outer membrane, which acts as a protective barrier against numerous Antibiotic, antibiotics (including penicillin), Detergent, detergents that would normally damage the inner cell membrane, and the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Negativicutes
The Negativicutes are a class of bacteria in the phylum Bacillota, whose members have a peculiar cell wall with a lipopolysaccharide outer membrane which stains gram-negative, unlike most other members of the Bacillota. Although several neighbouring ''Clostridia'' species (firmicute bacteria) also stain gram-negative, the proteins responsible for the unusual diderm structure of the ''Negativicutes'' may have actually been laterally acquired from Pseudomonadota (formerly Proteobacteria). Additional research is required to confirm the origin of the diderm cell envelope in the Negativicutes. Most members of this class are obligate anaerobes, and occur in habitats such as rivers, lakes, and the intestines of vertebrates. They range from spherical forms, such as ''Megasphaera'' and '' Veillonella'', to curved rods, as typified by the selenomonads. '' Selenomonas'' has a characteristic crescent shape, with flagella inserted on the concave side, while ''Sporomusa'' is similar, but n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heliobacteria
Heliobacteria are a unique subset of prokaryotic bacteria that process light for energy. Distinguishable from other phototrophic bacteria, they utilize a unique photosynthetic pigment, bacteriochlorophyll ''g'' and are the only known Gram-positive phototroph. They are a key player in symbiotic nitrogen fixation alongside plants, and use a type I reaction center like green-sulfur bacteria. RNA trees place the heliobacteria among the Bacillota. They have no outer membrane and like certain other Bacillota (Clostridia), they form heat-resistant endospores, which contain high levels of calcium and dipicolinic acid. Heliobacteria are the only Bacillota known to be phototrophic. Metabolism The heliobacteria are phototrophic: they convert light energy into chemical energy using a type I reaction center. The primary pigment involved is bacteriochlorophyll ''g'', which is unique to the group and has a unique absorption spectrum; this gives the heliobacteria their own environme ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thermolithobacteria
Thermolithobacteria is a class of rod-shaped Gram-positive bacteria within phylum Bacillota. Species within this class are thermophilic lithotrophs isolated from sediment in Calcite Springs in Yellowstone National Park. '' Thermolithobacter ferrireducens'' strain JW/KA-2(T) metabolism consists of the oxidation of hydrogen gas and reduction of ferric oxide to magnetite. '' Thermolithobacter carboxydivorans'' strain R1(T) is hydrogenic and oxidizes carbon monoxide. Taxonomy * Order Thermolithobacterales Sokolova et al. 2007 ** Family Thermolithobacteraceae Sokolova et al. 2007 *** Genus '' Thermolithobacter'' Sokolova et al. 2007 **** Species ''T. carboxydivorans'' Sokolova et al. 2007 **** Species ''T. ferrireducens'' Sokolova et al. 2007 (type species) See also * List of bacterial orders * List of bacteria genera This article lists the genera of the bacteria Bacteria (; : bacterium) are ubiquitous, mostly free-living organisms often consisting of one Cell (biology) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bacteria
Bacteria (; : bacterium) are ubiquitous, mostly free-living organisms often consisting of one Cell (biology), biological cell. They constitute a large domain (biology), domain of Prokaryote, 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 the air, soil, water, Hot spring, acidic hot springs, radioactive waste, and the deep biosphere of Earth's crust. Bacteria play a vital role in many stages of the nutrient cycle by recycling nutrients and the nitrogen fixation, fixation of nitrogen from the Earth's atmosphere, atmosphere. The nutrient cycle includes the decomposition of cadaver, 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, suc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endospore
An endospore is a dormant, tough, and non-reproductive structure produced by some bacteria in the phylum Bacillota. The name "endospore" is suggestive of a spore or seed-like form (''endo'' means 'within'), but it is not a true spore (i.e., not an offspring). It is a stripped-down, dormant form to which the bacterium can reduce itself. Endospore formation is usually triggered by a lack of nutrients, and usually occurs in Gram-positive bacteria. In endospore formation, the bacterium divides within its cell wall, and one side then engulfs the other. Endospores enable bacteria to lie dormant for extended periods, even centuries. There are many reports of spores remaining viable over 10,000 years, and revival of spores millions of years old has been claimed. There is one report of viable spores of '' Bacillus marismortui'' in salt crystals approximately 25 million years old. When the environment becomes more favorable, the endospore can reactivate itself into a vegetative state. Mos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zymophilus
''Zymophilus'' is a genus of Bacillota bacteria classified within the class Negativicutes. See the NCBI The National Center for Biotechnology Information (NCBI) is part of the National Library of Medicine (NLM), a branch of the National Institutes of Health (NIH). It is approved and funded by the government of the United States. The NCBI is loca ...br>webpage on NegativicutesData extracted from References Negativicutes Gram-negative bacteria Bacteria genera {{Firmicutes-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bacilli
Bacilli is a Taxonomy (biology), taxonomic Class (biology), class of bacteria that includes two orders, Bacillales and Lactobacillales, which contain several well-known pathogens such as ''Bacillus anthracis'' (the cause of anthrax). ''Bacilli'' are almost exclusively gram-positive bacteria. The name ''Bacillus'', capitalized and Italics, italicized, refers to a specific genus of bacteria. The name Bacilli, capitalized but not italicized, can also refer to a less specific taxonomic group of bacteria that includes two orders, one of which contains the genus ''Bacillus''. When the word is formatted with lowercase and not italicized, 'bacillus', it will most likely be referring to shape and not to the genus at all. Ambiguity Several related concepts make use of similar words, and the ambiguity can create considerable confusion. The term "''Bacillus''" (capitalized and italicized) is also the name of a genus (''Bacillus anthracis'') that, among many other genera, falls within the cl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pectinatus
''Pectinatus'' is a genus of Bacillota bacteria classified within the class Negativicutes. Phylogeny The currently accepted taxonomy is based on the List of Prokaryotic names with Standing in Nomenclature (LPSN) and National Center for Biotechnology Information (NCBI). See also * List of bacterial orders * List of bacteria genera This article lists the genera of the bacteria Bacteria (; : bacterium) are ubiquitous, mostly free-living organisms often consisting of one Cell (biology), biological cell. They constitute a large domain (biology), domain of Prokaryote, ... References Veillonellaceae Gram-negative bacteria Bacteria genera {{firmicutes-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Megasphaera
''Megasphaera'' is a genus of Bacillota bacteria classified within the class Negativicutes. This classification has been reexamined.Yutin N, Galperin MY (2013) A genomic update on Clostridial phylogeny: Gram-negative spore formers and other misplaced ''Clostridia''. Environ Microbiol doi: 10.1111/1462-2920.12173 It appears that this genus is a member of the ''Clostridia''. Phylogeny The currently accepted taxonomy is based on the List of Prokaryotic names with Standing in Nomenclature (LPSN) and National Center for Biotechnology Information (NCBI). Unassigned species: * "''M. intestinihominis''" Hitch et al. 2024 See also * List of bacterial vaginosis microbiota * List of bacterial orders * List of bacteria genera This article lists the genera of the bacteria Bacteria (; : bacterium) are ubiquitous, mostly free-living organisms often consisting of one Cell (biology), biological cell. They constitute a large domain (biology), domain of Prokaryote, ... Reference ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
