''Elusimicrobium minutum'' is an ultramicrobacterium and first accepted member to be cultured of a major bacterial lineage previously known only as

candidate phylum A candidate division, candidate phylum or candidate division-level is a lineage of prokaryotic organisms for which until recently no cultured representatives have been found, but evidence of the existence of the clade has been obtained by 16S rRN ...

Termite Gut 1 (TG1), which has accordingly been renamed phylum

Elusimicrobiota The phylum Elusimicrobiota, previously known as "Termite Group 1", has been shown to be widespread in different ecosystems like marine environment, sewage sludge, contaminated sites and soils, and toxic wastes. The high abundance of Elusimicrobio ...

. It was isolated in the laboratory of Andreas Brune at the

Max Planck Institute for Terrestrial Microbiology Max or MAX may refer to: Animals * Max (American dog) (1983–2013), at one time purported to be the world's oldest living dog * Max (British dog), the first pet dog to win the PDSA Order of Merit (animal equivalent of the OBE) * Max (gorilla) ( ...

, from the scarab beetle. It is a

mesophilic A mesophile is an organism that grows best in moderate temperature, neither too hot nor too cold, with an optimum growth range from . The optimum growth temperature for these organisms is 37 °C (about 99 °F). The term is mainly applied ...

, obligately anaerobic ultramicrobacterium with a

gram-negative Gram-negative bacteria are bacteria that, unlike gram-positive bacteria, do not retain the crystal violet stain used in the Gram staining method of bacterial differentiation. Their defining characteristic is that their cell envelope consists ...

cell envelope The cell envelope comprises the inner cell membrane and the cell wall of a bacterium. In Gram-negative bacteria an bacterial outer membrane, outer membrane is also included. This envelope is not present in the Mollicutes where the cell wall is abse ...

. Cells are typically rod shaped, but cultures are pleomorphic in all growth phases (0.3 to 2.5 μm long and 0.17 to 0.3 μm wide). The isolate grows heterotrophically on sugars and ferments D-galactose, D-glucose, D-fructose, D-glucosamine, and N-acetyl-D-glucosamine to acetate, ethanol, hydrogen, and alanine as major products but only if amino acids are present in the medium

The genome of ''Elusimicrobium minutum''

Th
1.64 Mbp genome
of ''E. minutum'' reveals the presences of several genes required for uptake and fermentation of sugars via the Embden–Meyerhof pathway, including several

hydrogenase A hydrogenase is an enzyme that Catalysis, catalyses the reversible Redox, oxidation of molecular hydrogen (H2), as shown below: Hydrogen oxidation () is coupled to the reduction of electron acceptors such as oxygen, nitrate, Ferric, ferric i ...

s, and an unusual peptide degradation pathway comprising transamination reactions. It also reveals the presence of genes coding for

peptidoglycan Peptidoglycan or murein is a unique large macromolecule, a polysaccharide, consisting of sugars and amino acids that forms a mesh-like layer (sacculus) that surrounds the bacterial cytoplasmic membrane. The sugar component consists of alternating ...

and

lipopolysaccharide Lipopolysaccharide (LPS), now more commonly known as endotoxin, is a collective term for components of the outermost membrane of the cell envelope of gram-negative bacteria, such as '' E. coli'' and ''Salmonella'' with a common structural archit ...

biosynthesis. The genome also seems to encode 60 PilE genes putatively involved in pilus assembly, polyketide synthesis, non-ribosomal peptide synthesis and many other still undiscovered metabolic traits.

References

{{Taxonbar, from=Q5360333 Bacteria by classification Bacteria described in 2010