Blastococcus montanus sp. nov., a multi-stress-resistant and bacteriostatic-producing bacterium isolated from the Flaming Mountain, Xinjiang,China

A bacterial strain designated HT6-4 T was isolated from soil samples collected from the Flaming Mountain, Xinjiang, PR China. The purpose of this study was to describe a novel species and its characteristics, through genome sequencing and analysis of the relationship between the members of the genus Blastococcus , and explore the antiradiation, antioxidation and antibacterial capabilities of strain HT6-4 T . The polyphasic study confirmed the affiliation of strain HT6-4 T with the genus Blastococcus . Strain HT6-4 T was aerobic, Gram-stain-positive, non-budding, non-motile, catalase-positive and oxidase-negative. It grew at 10–37 °C, pH 5.0–8.0 and 0–4% (w/v) NaCl. Colonies were circular, smooth and bright orange in colour. In addition, strain HT6-4 T was drought tolerant. The predominant menaquinone was MK-9, with MK-8 as the minor component. The polar lipids of strain HT6-4 T were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, phosphatidylinositol, phospholipids, an unidentified aminolipid and two unidentified phospholipids. Whole-cell hydrolysates contain meso -diaminopimelic acid as the diagnostic diamino acid and ribose and galactose as diagnostic sugars. Its major fatty acids were iso-C 16 : 0 , C 17 : 1 ω 8 c and C 18 : 1 ω 9 c . The genome of strain HT6-4 T was 4.30 Mb in the whole-genome shotgun project. The G+C content was 73.9 mol%. The phylogenetic analysis based on the 16S rRNA gene sequence showed that strain HT6-4 T was closely related to Blastococcus jejuensis KST3-10 T (97.9%), Blastococcus capsensis BMG 804 T (97.8%), Bl astococcus aggregatus DSM 4725 T (97.5%), Blastococcus saxobsidens BC 444 T (97.5%), Blastococcus xanthinilyticus BMG 862 T (97.5%) and Blastococcus litoris GP-S2-8 T (97.5%). The average nucleotide identity (OrthoANI) and digital DNA–DNA hybridization (dDDH) values among strain HT6-4 T and B. jejuensis KST3-10 T , B. capsensis BMG 804 T , B. aggregatus DSM 4725 T , B. saxobsidens BC 444 T , B. xanthinilyticus BMG 862 T and B. litoris GP-S2-8 T were below the species delimitation thresholds. The genome of strain HT6-4 T contained antiradiation genes, antioxidant genes and antibacterial genes. Based on its morphological, physiological and chemical taxonomic characteristics, strain HT6-4 T (=KCTC 59234 T =GDMCC 1.4386 T ) should be classified as a novel species of the genus Bl astococcus with the proposed name Blastococcus montanus sp. nov.