''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 rR ...

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 The Max Planck Institute for Terrestrial Microbiology (german: Max-Planck-Institut für terrestrische Mikrobiologie, links=https://de.wikipedia.org/wiki/Max-Planck-Institut_f%C3%BCr_terrestrische_Mikrobiologie) is a research institute for terrestr ...

, 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. The term is mainly applied to microorganisms. Org ...

, obligately anaerobic ultramicrobacterium with a

gram-negative Gram-negative bacteria are bacteria that do not retain the crystal violet stain used in the Gram staining method of bacterial differentiation. They are characterized by their cell envelopes, which are composed of a thin peptidoglycan cell wa ...

cell envelope The cell envelope comprises the inner cell membrane and the cell wall of a bacterium. In gram-negative bacteria an outer membrane is also included. This envelope is not present in the Mollicutes where the cell wall is absent. Bacterial cell env ...

. 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 Glycolysis is the metabolic pathway that converts glucose () into pyruvate (). The free energy released in this process is used to form the high-energy molecules adenosine triphosphate (ATP) and reduced nicotinamide adenine dinucleotide (NADH) ...

, including several hydrogenases, and an unusual peptide degradation pathway comprising

transamination reaction Transamination is a chemical reaction that transfers an amino group to a ketoacid to form new amino acids. This pathway is responsible for the deamination of most amino acids. This is one of the major degradation pathways which convert essential a ...

s. 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 peptidoglycan layer outside the plasma membrane, the rigid cell wall (murein sacculus) characteristic of most ba ...

and

lipopolysaccharide Lipopolysaccharides (LPS) are large molecules consisting of a lipid and a polysaccharide that are bacterial toxins. They are composed of an O- antigen, an outer core, and an inner core all joined by a covalent bond, and are found in the out ...

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