Methylobacillus

Abstract

Me.thy.lo.ba.cil'lus. N.L. neut. n. methylum the methyl radica; L. dim. masc. n. bacillus a small rod; N.L. masc. n. Methylobacillus methyl rodlet. Proteobacteria / Betaproteobacteria / Methylophilales / Methylophilaceae / Methylobacillus The genus Methylobacillus accommodates obligate and restricted facultative methylotrophs. Cells of these methylotrophic bacteria are Gram‐stain‐negative, aerobic, and asporogenous rods that are nonmotile or motile with 1–4 flagella, multiply by binary fission, and occur singly or rarely in pairs. Cells do not possess intracellular membranes or poly‐β‐hydroxybutyrate granules. Most members of the genus produce exopolysaccharide. No vitamins or other growth factors are required. No growth occurs on rich media with peptone and under CH 4 + O 2 or H 2 + CO 2 + O 2 in the gas phase. These methylotrophs are mesophilic and neutrophilic bacteria. Most strains are obligate methylotrophs; some strains, however, can also use fructose. All Methylobacillus species are able to utilize methanol via the ribulose monophosphate (RuMP) pathway of C 1 assimilation. Some of the Methylobacillus strains also possess the ability to grow on methylamine, which is directly oxidized to formaldehyde or utilized via the N ‐methylglutamate pathway. These bacteria possess an incomplete tricarboxylic acid cycle because they lack α‐ketoglutarate dehydrogenase. Glyoxylate shunt enzymes are absent. Ammonia, nitrate, and methylamine are used as the nitrogen sources. Ammonia is assimilated via glutamate dehydrogenase. Indole is produced from l ‐tryptophan on mineral medium with methanol and KNO 3 . The prevailing cellular fatty acids are straight‐chain saturated C 16:0 and unsaturated C 16:1 ω7 c acids. The known habitats are wastewater, activated sludge, soil, phyllosphere, and rhizosphere of various plants. DNA G + C content (mol%) : 50–61.5 ( T m and genome sequence). Type species : Methylobacillus glycogenes Yordy and Weaver 1977 AL .