Euryarchaeota is a kingdom of archaea. Euryarchaeota are highly diverse and include methanogens, which produce methane and are often found in intestines; halobacteria, which survive extreme concentrations of salt; and some extremely thermophilic aerobes and anaerobes, which generally live at temperatures between 41 and 122 °C. They are separated from the other archaeans based mainly on rRNA sequences and their unique DNA polymerase. The only validly published name for this group under the Prokaryotic Code is Methanobacteriati.
The Aquificota phylum is a diverse collection of bacteria that live in harsh environmental settings. The name Aquificota was given to this phylum based on an early genus identified within this group, Aquifex, which is able to produce water by oxidizing hydrogen. They have been found in springs, pools, and oceans. They are autotrophs, and are the primary carbon fixers in their environments. These bacteria are Gram-negative, non-spore-forming rods. They are true bacteria as opposed to the other inhabitants of extreme environments, the Archaea.
Desulfobacterales are an order of sulfate-reducing bacteria within the phylum Thermodesulfobacteria. The order contains three families; Desulfobacteraceae, Desulfobulbaceae, and Nitrospinaceae. The bacterium in this order are strict anaerobic respirators, using sulfate or nitrate as the terminal electron acceptor instead of oxygen. Desulfobacterales can degrade ethanol, molecular hydrogen, organic acids, and small hydrocarbons. The bacterium of this order have a wide ecological range and play important environmental roles in symbiotic relationships and nutrient cycling.
Desulfovibrionales are a taxonomic order of bacteria belonging to the phylum Thermodesulfobacteriota, with four families. They are Gram-negative. The majority are sulfate-reducing, with the exception of Lawsonia and Bilophila. All members of this order are obligately anaerobic. Most species are mesophilic, but some are moderate thermophiles.
The Syntrophobacterales are an order of Thermodesulfobacteriota. All genera are strictly anaerobic. Many of the family Syntrophobacteraceae are sulfate-reducing. Some species are motile by using one polar flagellum.
Desulfovibrionaceae is a family of bacteria belonging to the phylum Thermodesulfobacteriota.
Desulfohalobiaceae is a family of bacteria belonging to the phylum Thermodesulfobacteriota.
Chlorobium is a genus of green sulfur bacteria. They are photolithotrophic oxidizers of sulfur and most notably utilise a noncyclic electron transport chain to reduce NAD+. Photosynthesis is achieved using a Type 1 Reaction Centre using bacteriochlorophyll (BChl) a. Two photosynthetic antenna complexes aid in light absorption: the Fenna-Matthews-Olson complex, and the chlorosomes which employ mostly BChl c, d, or e. Hydrogen sulfide is used as an electron source and carbon dioxide its carbon source.
Fibrobacterota is a small bacterial phylum which includes many of the major rumen bacteria, allowing for the degradation of plant-based cellulose in ruminant animals. Members of this phylum were categorized in other phyla. The genus Fibrobacter was removed from the genus Bacteroides in 1988.
Campylobacterota are a phylum of Gram-negative bacteria. Until the 2021 revision of bacterial taxonomy by the ICSP, the entire phylum was classified within the Proteobacteria as the Epsilonproteobacteria and the Desulfurellales. The separation of this phylum from "Proteobacteria" was originally proposed in 2017, using GTDB-based methods.
The Myxococcota are a phylum of bacteria known as the fruiting gliding bacteria. All species of this group are Gram-negative. They are predominantly aerobic genera that release myxospores in unfavorable environments.
Chloracidobacterium is a genus of the Acidobacteriota. It is currently assigned to the family Acidobacteriaceae, but phylogenetic evidence suggests that it belongs in Blastocatellia.
Saccharibacteria, formerly known as TM7, is a major bacterial lineage. It was discovered through 16S rRNA sequencing.
Armatimonadota is a phylum of gram-negative bacteria.
Syntrophus is a Gram negative bacterial genus from the family of Syntrophaceae.
Atribacterota is a phylum of bacteria, which are common in anoxic sediments rich in methane. They are distributed worldwide and in some cases abundant in anaerobic marine sediments, geothermal springs, and oil deposits. Genetic analyzes suggest a heterotrophic metabolism that gives rise to fermentation products such as acetate, ethanol, and CO2. These products in turn can support methanogens within the sediment microbial community and explain the frequent occurrence of Atribacterota in methane-rich anoxic sediments. According to phylogenetic analysis, Atribacterota appears to be related to several thermophilic phyla within Terrabacteria or may be in the base of Gracilicutes. According to research, Atribacterota shows patterns of gene expressions which consists of fermentative, acetogenic metabolism. These expressions let Atribacterota to be able to create catabolic and anabolic functions which are necessary to generate cellular reproduction, even when the energy levels are limited due to the depletion of dissolved oxygen in the areas of sea waters, fresh waters, or ground waters.
Modulibacteria(Moduliflexota) is a bacterial phylum formerly known as KS3B3 or GN06. It is a candidate phylum, meaning there are no cultured representatives of this group. Members of the Modulibacteria phylum are known to cause fatal filament overgrowth (bulking) in high-rate industrial anaerobic wastewater treatment bioreactors.
NC10 is a bacterial phylum with candidate status, meaning its members remain uncultured to date. The difficulty in producing lab cultures may be linked to low growth rates and other limiting growth factors.
Nitrospinota is a bacterial phylum. Despite only few described species, members of this phylum are major nitrite-oxidizing bacteria in surface waters in oceans. By oxidation of nitrite to nitrate they are important in the process of nitrification in marine environments.
