Phenotypic and genomic characteristics of Brevibacterium zhoupengii sp. nov., a novel halotolerant actinomycete isolated from bat feces.

Two strictly aerobic, Gram-staining-positive, non-spore-forming, regular rod-shaped (approximately 0.7 × 1.9 mm) bacteria (HY170 and HY001) were isolated from bat feces collected from Chongzuo city, Guangxi province (22°20'54″N, 106°49'20″E, July 2011) and Chuxiong Yi Autonomous Prefecture, Yunnan province (25°09'10″N, 102°04'39″E, October 2013) of South China, respectively. Optimal growth is obtained at 25-28°C (range, 4-32°C) on BHI-5% sheep blood plate with pH 7.5 (range, 5.0-10.0) in the presence of 0.5-1.0% NaCl (w/v) (range, 0-15% NaCl [w/v]). The phylogenetic and phylogenomic trees based respectively on the 16S rRNA gene and 845 core gene sequences revealed that the two strains formed a distinct lineage within the genus Brevibacterium, most closely related to B. aurantiacum NCDO 739 (16S rRNA similarity, both 98.5%; dDDH, 46.7-46.8%; ANI, 91.9-92.1%). Strain HY170 contained MK-8(H), diphosphatidylglycerol (DPG) and phosphatidylglycerol (PG), galactose and ribose as the predominant menaquinone, major polar lipids, and main sugars in the cell wall teichoic acids, respectively. The meso-diaminopimelic acid (meso-DAP) was the diagnostic diamino acid of the peptidoglycan found in strain HY170. Anteiso-C and anteiso-C were the major fatty acids (> 10%) of strains HY170 and HY001, with anteiso-CA predominant in strain HY170 but absent in strain HY001. Mining the genomes revealed the presence of secondary metabolite biosynthesis gene clusters encoding for non-alpha poly-amino acids (NAPAA), ectoine, siderophore, and terpene. Based on results from the phylogenetic, chemotaxonomic and phenotypic analyses, the two strains could be classified as a novel species of the genus Brevibacterium, for which the name Brevibacterium zhoupengii sp. nov. is proposed (type strain HY170 = CGMCC 1.18600 = JCM 34230).