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.
A spirochaete or spirochete is a member of the phylum Spirochaetota, which contains distinctive diderm (double-membrane) Gram-negative bacteria, most of which have long, helically coiled cells. Spirochaetes are chemoheterotrophic in nature, with lengths between 3 and 500 μm and diameters around 0.09 to at least 3 μm.
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.
Verrucomicrobiota is a phylum of Gram-negative bacteria that contains only a few described species. The species identified have been isolated from fresh water, marine and soil environments and human faeces. A number of as-yet uncultivated species have been identified in association with eukaryotic hosts including extrusive explosive ectosymbionts of protists and endosymbionts of nematodes from genus Xiphinema, residing in their gametes. The verrucomicrobial bacterium Akkermansia muciniphila is a human intestinal symbiotic bacterium that is considered as a promising probiotic.
The Thermomicrobia is a group of thermophilic green non-sulfur bacteria. Based on species Thermomicrobium roseum and Sphaerobacter thermophilus, this bacteria class has the following description:
The Chlamydiota are a bacterial phylum and class whose members are remarkably diverse, including pathogens of humans and animals, symbionts of ubiquitous protozoa, and marine sediment forms not yet well understood. All of the Chlamydiota that humans have known about for many decades are obligate intracellular bacteria; in 2020 many additional Chlamydiota were discovered in ocean-floor environments, and it is not yet known whether they all have hosts. Historically it was believed that all Chlamydiota had a peptidoglycan-free cell wall, but studies in the 2010s demonstrated a detectable presence of peptidoglycan, as well as other important proteins.
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.
Nitrospirota is a phylum of bacteria. It includes multiple genera, such as Nitrospira, the largest. The first member of this phylum, Nitrospira marina, was discovered in 1985. The second member, Nitrospira moscoviensis, was discovered in 1995.
Armatimonadota is a phylum of gram-negative bacteria.
Dehalococcoidia is a class of Chloroflexota, a phylum of Bacteria. It is also known as the DHC group.
There are several models of the Branching order of bacterial phyla, one of these was proposed in 1987 paper by Carl Woese.
Chloroflexales is an order of bacteria in the class Chloroflexia. The clade is also known as filamentous anoxygenic phototrophic bacteria (FAP), as the order contains phototrophs that do not produce oxygen. These bacteria are facultative aerobic. They generally use chemotrophy when oxygen is present and switch to light-derived energy when otherwise. Most species are heterotrophs, but a few are capable of photoautotrophy.
Anaerolineaceae is a family of bacteria from the order of Anaerolineales. Anaerolineaceae bacteria occur in marine sediments. There are a total of twelve genera in this family, most of which only encompass one species. All known members of the family are Gram-negative and non-motile. They also do not form bacterial spores and are either mesophilic or thermophilic obligate anaerobes. It is also known that all species in this family are chemoheterotrophs.
Bellilinea is a thermophilic bacteria genus from the family of Anaerolineaceae with one known species. Bellilinea caldifistulae has been isolated from thermophilic digester sludge from Niigata in Japan.
Flexilinea is a bacterial genus from the family of Anaerolineaceae with one known species. Flexilinea flocculi has been isolated from methanogenic granular sludge.
Leptolinea is a bacteria genus from the family of Anaerolineaceae with one known species.
Levilinea is a bacteria genus from the family of Anaerolineaceae with one known species.
Longilinea is a bacteria genus from the family of Anaerolineaceae with one known species.
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.
