Methylophilus

Abstract

Abstract Me.thy.lo'phi.lus. N.L. pref. methylo‐ , pertaining to the methyl radical; N.L. masc. adj. philus , friend, loving; N.L. masc. n. Methylophilus , methyl radical loving. Proteobacteria / Betaproteobacteria / Methylophilales / Methylophilaceae / Methylophilus The genus Methylophilus is a group of restricted facultative methanol‐utilizing bacteria. Methanol is often used as a sole carbon source, while nitrate and ammonium salts are nitrogen sources. However, some species can also utilize other carbon sources, such as methylamines, glucose, fructose, dichloromethane, galactose, and formate. Metabolism of these substrates produces little to no acid. All species are aerobic, Gram‐negative rods that can occur singularly or in pairs. These cells can be motile or nonmotile and do not form endospores, cellular inclusions, sheaths, or prosthecae. Capsules are not observed. Some species may produce slime, mostly as viscous and nonviscous exopolysaccharides. Their colonies are circular with a complete edge and are translucent to opaque in opacity. Bacteria of this genus can grow on mineral salts agar plates with methanol, with optimum growth at 6.5–7.2 pH under aerobic conditions. Some members of the genus, that is, Methylophilus methylotrophus , display a high growth rate (up to 0.55 h −1 ), representing a prominent platform for biotechnological applications. Most species exhibit poor to no growth on nutritionally rich media, such as nutrient broth and blood agar. No growth occurs at 4 or 45°C. The major fatty acids are C 16 and C 16:1 . Members of this genus can be found in activated sludge, mud, river and pond water, oligotrophic oceanic waters, phyllospheres, and rhizospheres. DNA G + C content (mol%) : 50–53. Type species : Methylophilus methylotrophus Jenkins et al. 1987 VP .