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.
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.
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 Rhodospirillaceae are a family of Pseudomonadota. The majority are purple nonsulfur bacteria, producing energy through photosynthesis; originally all purple nonsulfur bacteria were included here.
Enterobacterales is an order of Gram-negative, non-spore forming, facultatively anaerobic, rod-shaped bacteria with the class Gammaproteobacteria. The type genus of this order is Enterobacter.
Sphingomonadaceae are a gram-negative bacterial family of the Alphaproteobacteria. An important feature is the presence of sphingolipids in the outer membrane of the cell wall. The cells are ovoid or rod-shaped. Others are also pleomorphic, i.e. the cells change the shape over time. Some species from Sphingomonadaceae family are dominant components of biofilms.
The Brucellaceae are a family of the Gram-negative Hyphomicrobiales. They are named after Sir David Bruce, a Scottish microbiologist. They are aerobic chemoorganotrophes. The family comprises pathogen and soil bacteria
The Desulfuromonadales are an order within the Thermodesulfobacteriota. Various members of the Desulfomonadales are capable of anaerobic respiration utilizing a variety of compounds as electron acceptors, including sulfur, Mn(IV), Fe(III), nitrate, Co(III), Tc(VII), U(VI) and trichloroacetic acid
The International Code of Nomenclature of Prokaryotes (ICNP) or Prokaryotic Code, formerly the International Code of Nomenclature of Bacteria (ICNB) or Bacteriological Code (BC), governs the scientific names for Bacteria and Archaea. It denotes the rules for naming taxa of bacteria, according to their relative rank. As such it is one of the nomenclature codes of biology.
Spirillum is a genus of Gram-negative bacteria in the family Spirillaceae of the Nitrosomonadales of the Betaproteobacteria. There are two species of Spirillum with validly or effectively published names - Spirillum winogradskyi and Spirillum volutans.
Rikenellaceae is a family of Gram-negative bacteria described by Noel R. Krieg in 2015. It contains nine genera, five of which are validly published by the International Code of Nomenclature of Prokaryotes. Bacteria with 16S ribosomal RNA highly similar to the Rikenella genus, as compared to the larger taxonomic order Bacteroidales, are classified in this family.
The family Saprospiraceae is composed of environmental bacteria. The members of this family are important to the breakdown of complex organic compounds in the environment.
Monera is historically a biological kingdom that is made up of prokaryotes. As such, it is composed of single-celled organisms that lack a nucleus. It has been superseded by the three-domain system.
Porphyromonas is a Gram-negative, non-spore-forming, obligately anaerobic and non-motile genus from the family Porphyromonadaceae. There were 16 different Porphyromonas species documented as of 2015, which reside in both animal and human reservoirs. It was discovered more recently that Porphyromonas also exist in the environment, albeit to a lesser extent. This genus is notably implicated in the modulation of oral cavity, respiratory tract, and gastrointestinal tract disease states. It is suggested that Porphyromonas either operate as benign bacteria pertinent to host immunity or are potential pathobionts that opportunistically provoke diseased states when homeostasis is disrupted. Despite its characterization not being fully elucidated due to sparse research, various studies report the prevalence of this genus at 58.7% in healthy states compared with 41.3% in diseased states.
Pelobacter is a bacterial genus in the order Desulfuromonadales. The cells are rod-shaped with rounded ends and occur in single, pairs or chains. They have a fermentative metabolism.
Phenylobacterium is a Gram negative, strictly aerobic non-motile and bacterial genus from the family of Caulobacteraceae which can grow on chloridazon–mineral salts.
Kofleriaceae is an aerobic family of bacteria from the order of Myxococcales.
Marinococcus is a Gram-positive, strictly aerobic, chemolithoautotrophic and non-spore-forming genus of bacteria from the family of Bacillaceae.
The Dermatophilaceae is a Gram-positive family of bacteria placed within the order of Actinomycetales. Dermatophilaceae bacteria occur on animal and human skin and in fish guts.
The Hahellaceae are a family of Pseudomonadota in the order of Oceanospirillales.
