Lysinibacillus cavernae sp. nov., isolated from cave soil

Abstract

A Gram-staining positive, motile, rod-shaped and subterminal endospore-forming bacterium, designated strain SYSU K30005^T, was isolated from a soil sample collected from a karst cave in Libo county, Guizhou province, south-western China. Strain SYSU K30005^T showed the highest 16S rRNA gene sequence similarity with Lysinibacillus fusiformis (98.6%) and Lysinibacillus sphaericus (98.2%). In phylogenetic tree, strain SYSU K30005^T clade with the members of the genus Lysinibacillus. Based on the phylogenetic and 16S gene sequence result, strain SYSU K30005^T was affiliated to the genus Lysinibacillus. The growth of SYSU K30005^T 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^T were ribose, galactose and mannose and MK-7 was the only quinone. The fatty acids (> 5% of total fatty acids) were iso-C_15:0, anteiso-C_15:0, iso-C_16:0 and iso-_C17:0. 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^T and its closest relatives were below the cut-off level (95-96%) for species delineation. The results support the conclusion that strain SYSU K30005^T represents a novel species of the genus Lysinibacillus, for which we proposed the name Lysinibacillus cavernae sp. nov. The type strain is SYSU K30005^T (= KCTC 43130^T = CGMCC 1.17492^T).

Keywords: Genome analysis; Karst cave; Lysinibacillus cavernae; Polyphasic taxonomy.