Lysinibacillus cavernae sp. nov., isolated from cave soil.

A Gram-staining positive, motile, rod-shaped and subterminal endospore-forming bacterium, designated strain SYSU K30005, was isolated from a soil sample collected from a karst cave in Libo county, Guizhou province, south-western China. Strain SYSU K30005 showed the highest 16S rRNA gene sequence similarity with Lysinibacillus fusiformis (98.6%) and Lysinibacillus sphaericus (98.2%). In phylogenetic tree, strain SYSU K30005 clade with the members of the genus Lysinibacillus. Based on the phylogenetic and 16S gene sequence result, strain SYSU K30005 was affiliated to the genus Lysinibacillus. The growth of SYSU K30005 was observed at 15-37 °C (optimum, 28 °C), pH 6.0-9.0 (optimum, pH 7.0) and in the presence of 0-4% (w/v) NaCl (optimum in 3.5% NaCl). Cell wall peptidoglycan type was A4α (Lys-Asp). The cell-wall sugars of SYSU K30005 were ribose, galactose and mannose and MK-7 was the only quinone. The fatty acids (> 5% of total fatty acids) were iso-C, anteiso-C, iso-C and iso-. The polar lipids profile included diphosphatidylglycerol, phosphatideylglycerol, phosphatidylethanolamine and an unidentified phospholipid. The genomic DNA G + C content was 37.2 mol%. The average nucleotide identity values between SYSU K30005 and its closest relatives were below the cut-off level (95-96%) for species delineation. The results support the conclusion that strain SYSU K30005 represents a novel species of the genus Lysinibacillus, for which we proposed the name Lysinibacillus cavernae sp. nov. The type strain is SYSU K30005 (= KCTC 43130 = CGMCC 1.17492).