Pseudomonadota in the context of "Gammaproteobacteria"

Stromatolites (/stroʊˈmætəˌlaɪts, strə-/ stroh-MAT-ə-lytes, strə-) or stromatoliths (from Ancient Greek στρῶμα (strôma), GEN στρώματος (strṓmatos) 'layer, stratum' and λίθος (líthos) 'rock') are layered sedimentary formations (microbialite) that are created mainly by photosynthetic microorganisms such as cyanobacteria, sulfate-reducing bacteria, and Pseudomonadota (formerly proteobacteria). These microorganisms produce adhesive compounds that cement sand and other rocky materials to form mineral "microbial mats". In turn, these mats build up layer by layer, growing gradually over time.

This process generates the characteristic lamination of stromatolites, a feature that is hard to interpret, in terms of its temporal and environmental significance. Different styles of stromatolite lamination have been described, which can be studied through microscopic and mathematical methods. A stromatolite may grow to a meter or more. Fossilized stromatolites provide important records of some of the most ancient life. As of the Holocene, living forms are rare.

Enterobacteriaceae is a large family of Gram-negative bacteria. It includes over 30 genera and more than 100 species. Its classification above the level of family is still a subject of debate, but one classification places it in the order Enterobacterales of the class Gammaproteobacteria in the phylum Pseudomonadota. In 2016, the description and members of this family were emended based on comparative genomic analyses by Adeolu et al.

Enterobacteriaceae includes, along with many harmless symbionts, many of the more familiar pathogens, such as Salmonella, Escherichia coli, Klebsiella, and Shigella. Other disease-causing bacteria in this family include Enterobacter and Citrobacter. Members of the Enterobacteriaceae can be trivially referred to as enterobacteria or "enteric bacteria", as several members live in the intestines of animals. In fact, the etymology of the family is enterobacterium with the suffix to designate a family (aceae)—not after the genus Enterobacter (which would be "Enterobacteraceae")—and the type genus is Escherichia.

Alphaproteobacteria or α-proteobacteria, also called α-Purple bacteria in earlier literature, is a class of bacteria in the phylum Pseudomonadota (also called "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, although some of its intracellular parasitic members lack peptidoglycan and are consequently gram variable.

The Rhodospirillaceae are a family of bacteria within the Pseudomonadota. The family is metabolically diverse, though it is known for its purple nonsulfur bacteria, which produce energy through photosynthesis. Originally, all purple nonsulfur bacteria were classified in this family.

Members of this family are often found in anaerobic aquatic environments, such as mud and stagnant water, though they are capable of surviving in the presence of air. A notable genus, Magnetospirillum, exhibits magnetotaxis. These bacteria contain internal chains of magnetite that allow them to orient themselves along the Earth's magnetic field lines, aiding their movement toward the sediment of ponds where they live. The discovery of similar magnetite structures in Martian meteorites has led to speculation about the possibility of ancient life on Mars.

Beggiatoa is a genus of Gammaproteobacteria belonging to the order Thiotrichales, in the Pseudomonadota phylum. These bacteria form colorless filaments composed of cells that can be up to 200 μm in diameter, and are one of the largest prokaryotes on Earth. Beggiatoa are chemolithotrophic sulfur-oxidizers, using reduced sulfur species as an energy source. They live in sulfur-rich environments such as soil, both marine and freshwater, in the deep sea hydrothermal vents, and in polluted marine environments. In association with other sulfur bacteria, e.g. Thiothrix, they can form biofilms that are visible to the naked eye as mats of long white filaments; the white color is due to sulfur globules stored inside the cells.

Acidithiobacillia is a class of the phylum Pseudomonadota ("Proteobacteria"). Its type order, the Acidithiobacillales, was formerly classified within the Gammaproteobacteria, and comprises two families of sulfur-oxidising autotrophs, the Acidithiobacillaceae and the Thermithiobacillaceae, which in turn include the genera Acidithiobacillus and Thermithiobacillus. The Acidithiobacillales are an order of bacteria within the class Acidithiobacillia and comprises the genera Acidithiobacillus and Thermithiobacillus. Originally, both were included in the genus Thiobacillus, but they are not related to the type species, which belongs to the Betaproteobacteria.

Acidithiobacilia is part of the acidophilic bacteria family. Acidithiobacilia's metabolic activity is important because it is relied on for an approach for metal recovery from ores, called microorganism-mediated biohydrometallurgy. Acidithiobacilia and family of bacteria are active players in the sulfur and iron biogeochemical cycles in extremely acidic environments and drivers of the leaching of mineral ores contributing to acid rock/mine drainage and industrial bioleaching.

Betaproteobacteria are a class of Gram-negative bacteria, and one of the six classes of the phylum Pseudomonadota (synonym Proteobacteria).