Pseudomonadota is a major phylum of Gram-negative bacteria. The renaming of several prokaryote phyla in 2021, including Pseudomonadota, remains controversial among microbiologists, many of whom continue to use the earlier name Proteobacteria, 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. Others are free-living (non-parasitic) and include many of the bacteria responsible for nitrogen fixation.
Mycoplasma is a genus of bacteria that, like the other members of the class Mollicutes, lack a cell wall around their cell membranes. Peptidoglycan (murein) is absent. This characteristic makes them naturally resistant to antibiotics that target cell wall synthesis. They can be parasitic or saprotrophic. Several species are pathogenic in humans, including M. pneumoniae, which is an important cause of "walking" pneumonia and other respiratory disorders, and M. genitalium, which is believed to be involved in pelvic inflammatory diseases. Mycoplasma species are among the smallest organisms yet discovered, can survive without oxygen, and come in various shapes. For example, M. genitalium is flask-shaped, while M. pneumoniae is more elongated, many Mycoplasma species are coccoid. Hundreds of Mycoplasma species infect animals.
Nanoarchaeota is a proposed phylum in the domain Archaea that currently has only one representative, Nanoarchaeum equitans, which was discovered in a submarine hydrothermal vent and first described in 2002.
Acinetobacter is a genus of Gram-negative bacteria belonging to the wider class of Gammaproteobacteria. Acinetobacter species are oxidase-negative, exhibit twitching motility, and occur in pairs under magnification.
The Hyphomicrobiales are an order of Gram-negative Alphaproteobacteria.
In microbiology, genetics, cell biology, and molecular biology, competence is the ability of a cell to alter its genetics by taking up extracellular ("naked") DNA from its environment in the process called transformation. Competence may be differentiated between natural competence, a genetically specified ability of bacteria which is thought to occur under natural conditions as well as in the laboratory, and induced or artificial competence, which arises when cells in laboratory cultures are treated to make them transiently permeable to DNA. Competence allows for rapid adaptation and DNA repair of the cell. This article primarily deals with natural competence in bacteria, although information about artificial competence is also provided.
Alphaproteobacteria is a class of bacteria in the phylum Pseudomonadota. 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.
Pink-Pigmented Facultative Methylotrophs, commonly abbreviated to PPFMs, are bacteria that are members of the genus Methylobacterium and are commonly found in soil, dust, various fresh water supplies and on plant surfaces. Although Gram negative, Methylobacteria often stain gram variable and are easily isolated using methanol-based mineral medium. Their pigmentation, which is frequently pink but may also be yellow or orange, is thought to provide protection from solar UV radiation which damages the DNA of bacteria at low doses because of their small cell size. This color is present due to the carotenoid pigments within the cell.
Sulfolobales is an order of archaeans in the class Thermoprotei.
Streptococcus oralis is a Gram positive bacterium that grows characteristically in chains. It forms small white colonies on a Wilkins-Chalgren agar plate. It is found in high numbers in the oral cavity. It has been classified as a member of the Streptococcus mitis group. Members of this group are opportunistic pathogens. Strains of S. oralis produce neuraminidase and an IgA protease and cannot bind α-amylase.
Methylorubrum extorquens is a Gram-negative bacterium. Methylorubrum species often appear pink, and are classified as pink-pigmented facultative methylotrophs, or PPFMs. The wild type has been known to use both methane and multiple carbon compounds as energy sources. Specifically, M. extorquens has been observed to use primarily methanol and C1 compounds as substrates in their energy cycles. It has been also observed that use lanthanides as a cofactor to increase its methanol dehydrogenase activity
Deinococcus is in the monotypic family Deinococcaceae, and one genus of three in the order Deinococcales of the bacterial phylum Deinococcota highly resistant to environmental hazards. These bacteria have thick cell walls that give them Gram-positive stains, but they include a second membrane and so are closer in structure to Gram-negative bacteria. Deinococcus survive when their DNA is exposed to high doses of gamma and UV radiation. Whereas other bacteria change their structure in the presence of radiation, such as by forming endospores, Deinococcus tolerate it without changing their cellular form and do not retreat into a hardened structure. They are also characterized by the presence of the carotenoid pigment deinoxanthin that give them their pink color. They are usually isolated according to these two criteria. In August 2020, scientists reported that bacteria from Earth, particularly Deinococcus bacteria, were found to survive for three years in outer space, based on studies conducted on the International Space Station. These findings support the notion of panspermia, the hypothesis that life exists throughout the Universe, distributed in various ways, including space dust, meteoroids, asteroids, comets, planetoids or contaminated spacecraft.
Methylorubrum rhodesianum is a species of alphaproteobacteria. It has been found on the International Space Station (ISS) amongst others.
Methylorubrum zatmanii is a bacterium.
Methylobacterium oryzae is a facultatively methylotrophic and aerobic bacteria from the genus of Methylobacterium which has been isolated from tissues of the rice plant Oryza sativa in Cheongwon in Korea. Methylobacterium oryzae can utilize 1-aminocyclopropane 1-carboxylate. Methylobacterium oryzae can promote plant growth.
Methylorubrum pseudosasae is a Gram-negative, aerobic, facultatively methylotrophic bacteria from the genus Methylorubrum which has been isolated from bamboo leaves.
Streptomyces pini is a bacterium species from the genus of Streptomyces which has been isolated from the phylloplane of a pine in Coimbatore in India.
Chitinophagaceae is an aerobic or facultatively anaerobic and rod-shaped family of bacteria in the phylum Bacteroidota.
Riemerella columbina is a Gram-negative bacterium from the genus of Riemerella which can cause respiratory disease in pigeons.
Methylobacterium ajmalii is a species of Methylobacterium.
