Microbacterium sorbitolivorans sp. nov., a novel member of Microbacteriaceae isolated from fermentation bed in pigpen

Two bacterial strains SZDIS-1-1T and GZDIS-1-1 were isolated from fermentation bed of a pigpen in Fujian Province, China. Cells were Gram-stain-positive, facultatively anaerobic, short rods without flagellum. Their nearest phylogenetic neighbours were Microbacterium amylolyticum N5T (16S rRNA gene sequence similarity 98.2 %), Microbacterium indicum BBH6T (97.9 %) and Microbacterium gubbeenense DPC 5286T (97.8 %) with the DNA-DNA hybridization values to strain SZDIS-1-1T as 20.0±1.2, 14.3±5.8 and 19.1±1.6 %, respectively. The DNA G+C content of the new isolates was 67.6-71.1 mol% and anteiso-C15 : 0, anteiso-C17 : 0 and iso-C16 : 0 were their predominant cellular fatty acids. These results were consistent with classification into the genus Microbacterium. However, cell-wall sugars and characteristic amino acid were rhamnose, glucose, galactose and ornithine. Major menaquinones were MK-11 and MK-10. The polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol, glycolipids, unknown phospholipid and unknown lipids. These characteristics constructed a distinct profile of the two isolates. Therefore, based on polyphasic taxonomic characteristics, strains SZDIS-1-1T and GZDIS-1-1 represented a novel species of genus Microbacterium, for which the name Microbacterium sorbitolivorans sp. nov. is proposed, with strain SZDIS-1-1T (=CGMCC 1.15228T=DSM 103422T) as the type strain.