Aquisalibacillus elongatus gen. nov., sp. nov., a moderately halophilic bacterium of the family Bacillaceae isolated from a saline lake

Abstract

A novel moderately halophilic, non-motile, rod-shaped bacterium was isolated from a saline lake, Lake Shangmatala, in the Inner Mongolia Autonomous Region, China. This bacterium, designated SH4sT, was strictly aerobic, catalase-positive and oxidase-negative. It grew at salinities of 3-20% (w/v) NaCl, with an optimum at 10% (w/v) NaCl. The cell-wall peptidoglycan was of the A4β type, based on L-Orn-D-Asp, and the major quinone was a menaquinone with seven isoprene units (MK-7). The major fatty acids were iso-C16:0 and iso-C15:0. The polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, a glycolipid and four different unidentified phospholipids. The DNA G+C content was 45.9 mol%. In a maximum-parsimony phylogenetic tree based on 16S rRNA gene sequences, strain SH4sT was found to belong to the family Bacillaceae and to be most closely related to members of the genera Filobacillus (95.9% sequence similarity), Piscibacillus (95.7 %) and Tenuibacillus (95.4 %). DNA-DNA hybridization experiments revealed 10% relatedness (12 %, reciprocally) between strain SH4sT and Filobacillus milosensis DSM 13259T, the sole species of the genus. All of these data show that strain SH4sT represents a novel genus and species in the family Bacillaceae, for which the name Aquisalibacillus elongatus gen. nov., sp. nov. is proposed. The type strain of Aquisalibacillus elongatus is SH4sT (=CCM 7366T =CECT 7149T =DSM 18090T). © 2008 IUMS.