Microbacterium rhizomatis sp. nov., a β-glucosidase-producing bacterium isolated from rhizome of Korean mountain ginseng.

A novel Gram-staining-positive, rod-shaped bacterium, designated DCY100(T), was isolated from rhizome of mountain ginseng root in Hwacheon mountain, Gangwon province, Republic of Korea. The 16S rRNA gene sequence analysis showed that strain DCY100(T) belonged to the genus Microbacterium and was most closely related to Microbacterium ginsengisoli KCTC 19189(T) (97.9%), Microbacterium lacus JCM 15575(T) (97.2%) and Microbacterium invictum DSM 19600(T) (97.1%). The major menaquinones were MK-11 and MK-12. The major polar lipids were found to be diphosphatidylglycerol, phosphatidylglycerol and one unidentified glycolipid. The major fatty acids (>10.0%) were anteiso-C15 : 0, anteiso-C17 : 0 and iso-C16 : 0. The cell-wall peptidoglycan contained the amino acids ornithine, alanine, glutamic acid and glycine; whole-cell sugars consisted of glucose, galactose, rhamnose and ribose. The DNA G+C content was 63.6 ± 0.7 mol%. The DNA-DNA hybridization relatedness values between strain DCY100(T) and Microbacterium ginsengisoli KCTC 19189(T), Microbacterium lacus JCM 15575(T) and Microbacterium invictum DSM 19600(T) were 36.2 ± 0.4, 22.0 ± 3.0 and 15.3 ± 1.8%, respectively. On the basis of phenotypic, chemotaxonomic and genotypic analyses, the isolate is classified as a representative of a novel species in the genus Microbacterium, for which the name Microbacterium rhizomatis DCY100(T) is proposed. The type strain is DCY100(T) ( = KCTC 39529(T) = JCM 30598(T)).