Microbacterium wangchenii sp. nov., isolated from faeces of Tibetan gazelles (Procapra picticaudata) on the Qinghai-Tibet Plateau

Abstract

Two strains of Gram-stain-positive, aerobic, non-spore-forming, non-motile, rod-shaped bacteria (designated dk512T and dk508) were isolated from the faeces of Tibetan gazelle (Procapra picticaudata) collected from the Qinghai-Tibet Plateau, PR China. The 16S rRNA gene sequences of the strains showed the highest identity to Microbacterium saccharophilum K-1T (98.0 and 97.9 % similarity, respectively). The phylogenetic analysis based on 16S rRNA gene sequences revealed that dk512T and dk508 were members of the genus Microbacterium , and most closely related to strains Microbacterium mitrae M4-8T and Microbacterium hatanonis FCC-01T. The strains grew optimally on brain-heart infusion (BHI) agar with 5.0 % (v/v) sheep blood at 30 °C, pH 7.0 and with 1.0 % (w/v) NaCl. The genome of type strain dk512T was 3.8 Mb with a G+C content of 70.6 mol%. The average nucleotide identity and digital DNA–DNA hybridization values between strain dk512T and previously characterized Microbacterium species were <95 and <70 %, respectively. In strain dk512T, the detected primary cellular fatty acids were anteiso-C15 : 0 and anteiso-C17 : 0, the main respiratory quinones were MK-9 (37.9 %) and MK-10 (35.7 %), and the polar lipids included diphosphatidylglycerol, phosphatidylglycerol and three unidentified glycolipids. The major cell-wall sugars were rhamnose, ribose and galactose. Alanine, glutamic acid, glycine and ornithine were in the cell-wall peptidoglycan. Based on phenotypic data and phylogenetic inference, these two strains represent a novel species of the genus Microbacterium , named here as Microbacterium wangchenii sp. nov, where dk512T is designated the type strain (=CGMCC 1.16590T=JCM 33494T=KCTC 49313T).