The Actinomycetota are a diverse phylum of Gram-positive bacteria with high G+C content. They can be terrestrial or aquatic. They are of great economic importance to humans because agriculture and forests depend on their contributions to soil systems. In soil they help to decompose the organic matter of dead organisms so the molecules can be taken up anew by plants. While this role is also played by fungi, Actinomycetota are much smaller and likely do not occupy the same ecological niche. In this role the colonies often grow extensive mycelia, like a fungus would, and the name of an important order of the phylum, Actinomycetales, reflects that they were long believed to be fungi. Some soil actinomycetota live symbiotically with the plants whose roots pervade the soil, fixing nitrogen for the plants in exchange for access to some of the plant's saccharides. Other species, such as many members of the genus Mycobacterium, are important pathogens.
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.
The Chloroflexia are a class of bacteria in the phylum Chloroflexota. Chloroflexia are typically filamentous, and can move about through bacterial gliding. It is named after the order Chloroflexales.
The phylum Bacteroidota is composed of three large classes of Gram-negative, nonsporeforming, anaerobic or aerobic, and rod-shaped bacteria that are widely distributed in the environment, including in soil, sediments, and sea water, as well as in the guts and on the skin of animals.
The Campylobacterales are an order of Campylobacterota which make up the epsilon subdivision, together with the small family Nautiliaceae. They are Gram-negative. Most of the species are microaerophilic.
The Actinomycetales is an order of Actinomycetota. A member of the order is often called an actinomycete. Actinomycetales are generally gram-positive and anaerobic and have mycelia in a filamentous and branching growth pattern. Some actinomycetes can form rod- or coccoid-shaped forms, while others can form spores on aerial hyphae. Actinomycetales bacteria can be infected by bacteriophages, which are called actinophages. Actinomycetales can range from harmless bacteria to pathogens with resistance to antibiotics.
The Thermotogota are a phylum of the domain Bacteria. The phylum contains a single class, Thermotogae. The phylum Thermotogota is composed of Gram-negative staining, anaerobic, and mostly thermophilic and hyperthermophilic bacteria.
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.
The Bifidobacteriaceae are the only family of bacteria in the order Bifidobacteriales. According to the 16S rRNA-based LTP release 106 published by 'The All-Species Living Tree' Project, the order Bifidobacteriales is a clade nested within the suborder Micrococcineae, also the genus Bifidobacterium is paraphyletic to the other genera within the family, i.e. the other genera are nested within Bifidobacterium.
The Coriobacteriales are an order of Actinomycetota.
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.
The order Flavobacteriales comprises several families of environmental bacteria.
The Pseudonocardiaceae are a family of bacteria in the order Actinomycetales and the only member of the suborder Pseudonocardineae.
The Synergistota is a phylum of anaerobic bacteria that show Gram-negative staining and have rod/vibrioid cell shape. Although Synergistota have a diderm cell envelope, the genes for various proteins involved in lipopolysaccharides biosynthesis have not yet been detected in Synergistota, indicating that they may have an atypical outer cell envelope. The Synergistota inhabit a majority of anaerobic environments including animal gastrointestinal tracts, soil, oil wells, and wastewater treatment plants and they are also present in sites of human diseases such as cysts, abscesses, and areas of periodontal disease. Due to their presence at illness related sites, the Synergistota are suggested to be opportunistic pathogens but they can also be found in healthy individuals in the microbiome of the umbilicus and in normal vaginal flora. Species within this phylum have also been implicated in periodontal disease, gastrointestinal infections and soft tissue infections. Other species from this phylum have been identified as significant contributors in the degradation of sludge for production of biogas in anaerobic digesters and are potential candidates for use in renewable energy production through their production of hydrogen gas. All of the known Synergistota species and genera are presently part of a single class (Synergistia), order (Synergistiales), and family (Synergistaceae).
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 also stain gram-negative, the proteins responsible for the unusual diderm structure of the Negativicutes may have actually been laterally acquired from Pseudomonadota. Additional research is required to confirm the origin of the diderm cell envelope in the Negativicutes.
Adlercreutzia is a genus in the phylum Actinomycetota (Bacteria).
The Cryptosporangiaceae are the only family of the order Cryptosporangiales, which is a part of the phylum Actinomycetota.
The Coriobacteriia are a class of Gram-positive bacteria within the Actinomycetota phylum. Species within this group are nonsporulating, strict or facultative anaerobes that are capable of thriving in a diverse set of ecological niches. Gordonibacter species are the only members capable of motility by means of flagella within the class. Several species within the Coriobacteriia class have been implicated with human diseases that range in severity. Atopobium, Olsenella, and Cryptobacterium species have responsible for human oral infections including periodontitis, halitosis, and other endodontic infections. Eggerthella species have been associated with severe blood bacteraemia and ulcerative colitis.
The Eggerthellaceae are a family of Gram-positive, rod- or coccus-shaped Actinomycetota. It is the sole family within the order Eggerthellales.
Natrialbales is an order of halophilic, chemoorganotrophic archaea within the class Haloarchaea. The type genus of this order is Natrialba.
