Microbacterium ulmi sp. nov., a xylanolytic, phosphate-solubilizing bacterium isolated from sawdust of Ulmus nigra

A xylanolytic and phosphate-solubilizing bacterium isolated from sawdust of Ulmus nigra in Salamanca was characterized by a polyphasic approach. The novel strain, designated XIL02(T), was Gram-positive, aerobic, catalase- and oxidase-negative, rod-shaped and non-motile. Phylogenetically and chemotaxonomically, it was related to members of the genus Microbacterium. According to 16S rRNA gene sequence analysis, it is closely related to Microbacterium arborescens and Microbacterium imperiale; however, DNA-DNA hybridization showed reassociation values less than 70 % with the type strains of these species. In chemotaxonomic analyses, the major menaquinones detected were MK-12, MK-13 and MK-11 and the major fatty acids were anteiso-C(15 : 0), anteiso-C(17 : 0) and iso-C(16 : 0); the peptidoglycan was of the type B2beta. The G+C content determined was 69 mol%. Based on the present data, it is proposed that strain XIL02(T) (=LMG 20991(T)=CECT 5976(T)) be classified as the type strain of a novel Microbacterium species, for which the name Microbacterium ulmi sp. nov. is proposed.