Abstract
A marine methylotroph, designated strain MB2(T), was isolated for its ability to grow on methyl bromide as a sole carbon and energy source. Methyl chloride and methyl iodide also supported growth, as did methionine and glycine betaine. A limited amount of growth was observed with dimethyl sulfide. Growth was also noted with unidentified components of the complex media marine broth 2216, yeast extract and Casamino acids. No growth was observed on methylated amines, methanol, formate, acetate, glucose or a variety of other substrates. Growth on methyl bromide and methyl iodide resulted in their oxidation to CO(2) with stoichiometric release of bromide and iodide, respectively. Strain MB2(T) exhibited growth optima at NaCl and Mg(2+) concentrations similar to that of seawater. Phylogenetic analysis of the 16S rDNA sequence placed this strain in the alpha-Proteobacteria in proximity to the genera Ruegeria and Roseobacter. It is proposed that strain MB2(T) (=ATCC BAA-92(T)=DSM 14336(T)) be designated Leisingera methylohalidivorans gen. nov., sp. nov.