Microbacterium oleivorans sp. nov. and Microbacterium hydrocarbonoxydans sp. nov., novel crude-oil-degrading Gram-positive bacteria.

A taxonomic study of two crude-oil-degrading, Gram-positive bacterial strains, designated BAS69(T) and BNP48(T), revealed that they represent two novel Microbacterium species. 16S rRNA gene sequence similarity to their closest phylogenetic neighbours was 98.5 % for BAS69(T) (Microbacterium paraoxydans DSM 15019(T) and Microbacterium saperdae DSM 20169(T)) and 99 % for BNP48(T) (Microbacterium luteolum DSM 20143(T)). Levels of DNA-DNA relatedness to the closest phylogenetic neighbours of both strains were between 11 and 38 %. According to phylogenetic analysis, the two strains are distinguishable from all recognized species of Microbacterium. Morphological and physiological characteristics of strains BAS69(T) and BNP48(T) were different from those of phylogenetically closely related Microbacterium species. The diamino acid in the cell-wall peptidoglycan of BAS69(T) is lysine and of BNP48(T) is ornithine. The major menaquinones are MK-11 and MK-12 for both strains. Based on their ability to degrade crude oil, the name Microbacterium oleivorans sp. nov. is proposed for strain BAS69(T) (=DSM 16091(T)=NCIMB 14003(T)) and Microbacterium hydrocarbonoxydans is proposed for strain BNP48(T) (=DSM 16089(T)=NCIMB 14002(T)).