Ornithinimicrobium cavernae sp. nov., an actinobacterium isolated from a karst cave.

A novel actinobacterium, designated strain CFH 30183, was isolated from a soil sample collected from a karst cave in Luoyang, Henan Province. The taxonomic position of the strain was investigated using a polyphasic approach. Cells of strain CFH 30183 were observed to be Gram-stain positive, motile, asporogenous and coccoid to rod shaped. The strain was found to be aerobic and oxidase positive. On the basis of 16S rRNA gene sequence analysis, strain CFH 30183 was found to be closely related to Ornithinimicrobium murale 01-Gi-040 (97.8% sequence identity). The ANIb/ANIm values between strain CFH 30183 and O. murale DSM 22056 were found to be 80.3%/85.9%. Strain CFH 30183 was found to grow optimally at 28-32 °C, at pH 8.0-9.0 and in the presence of up to 7% NaCl (w/v). Whole cell hydrolysates of strain CFH 30183 contained L-ornithine as the diagnostic diamino acid, and arabinose, glucose, mannose and rhamnose as whole cell sugars. The respiratory quinone was determined to be MK-8(H), while the major fatty acids were found to consist of iso-C and iso-C. The polar lipids profile was found to include diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, an unidentified phospholipid, an unidentified phosphoglycolipid and four unidentified lipids. The DNA G + C content of strain CFH 30183 was calculated to be 70.9%. Based on the phenotypic, genotypic and phylogenetic data obtained, strain CFH 30183 is considered to represent a novel species of the genus Ornithinimicrobium, for which the name Ornithinimicrobium cavernae sp. nov. is proposed. The type strain is CFH 30183 (= KCTC 49018 = CGMCC 1.16393).