Methylibium fulvum sp. nov., a member of the Betaproteobacteria isolated from ginseng field soil, and emended description of the genus Methylibium
Two bacterial strains, designated Gsoil 322T and Gsoil 328, were isolated from soil of a ginseng field in Pocheon province (Republic of Korea). The strains were Gram-negative, motile, aerobic rods that showed nearly identical physiological profiles and similar chemotaxonomic profiles. The two strains were oxidase-positive but catalase-negative, reduced nitrate to nitrite and had fatty acid profiles in which C16 : 0, C17 : 0 cyclo and C16 : 1 ω7c/iso-C15 : 0 2-OH were predominant. The DNA G+C contents of Gsoil 322T and Gsoil 328 were 66.6 and 66.7 mol%, respectively. Q-8 was observed as the major quinone. Comparative 16S rRNA gene sequence analysis showed that strain Gsoil 322T belongs to the class Betaproteobacteria and was most closely related to Methylibium petroleiphilum ATCC BAA-1232T (97.5 % sequence similarity). On the basis of its phenotypic properties and phylogenetic distinctiveness, strain Gsoil 322T (=KCTC 12591T =LMG 23394T) was classified in the genus Methylibium as the type strain of a novel species, for which the name Methylibium fulvum sp. nov. is proposed.