Aquisalibacillus elongatus gen. nov., sp. nov., a moderately halophilic bacterium of the family Bacillaceae isolated from a saline lake M. C. Ma ´ rquez, 1 I. J. Carrasco, 1 Y. Xue, 2 Y. Ma, 2 D. A. Cowan, 3 B. E. Jones, 4 W. D. Grant 5 and A. Ventosa 1 Correspondence M. C. Ma ´ rquez cmarquez@us.es 1 Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Sevilla, 41012 Sevilla, Spain 2 State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, 100080 Beijing, PR China 3 Institute for Microbial Biotechnology and Metagenomics, University of the Western Cape, Bellville 7535, Cape Town, South Africa 4 Genencor International BV, 2333 CN Leiden, The Netherlands 5 Department of Infection, Immunity and Inflammation, University of Leicester, Leicester LE1 9HN, UK 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 SH4s T , 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 A4b 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-C 16 : 0 and iso-C 15 : 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 SH4s T 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 SH4s T and Filobacillus milosensis DSM 13259 T , the sole species of the genus. All of these data show that strain SH4s T 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 SH4s T (5CCM 7366 T 5CECT 7149 T 5DSM 18090 T ). Moderately halophilic bacteria that grow optimally in media containing 3–15 % NaCl are widely distributed in different saline environments such as salt lakes, salterns and salty foods (Ventosa et al., 1998). Moderately halophilic, aerobic, Gram-positive rods are taxonomically diverse and are represented in many genera within the family Bacillaceae. Three of these genera, namely Filobacillus (Schlesner et al., 2001), Tenuibacillus (Ren & Zhou, 2005) and Piscibacillus (Tanasupawat et al., 2007), form a coherent phylogenetic cluster within rRNA group I of Bacillus (Ash et al., 1991). To date, only a single species has been recognized for each of these genera, Filobacillus milosensis, Tenuibacillus multivorans and Piscibacillus salipiscarius. During an investigation of the presence of halophilic bacteria in saline lakes in China, we isolated a moderately halophilic organism, designated strain SH4s T , that shared many physiological and biochemical character- istics with species of the genera mentioned above, but was distinctive in terms of its peptidoglycan composition and DNA G+C content. Furthermore, 16S rRNA gene sequence analysis showed that this organism represents a novel subline within the family Bacillaceae. In this study, morphological, cultural, physiological, biochemical, che- motaxonomic and phylogenetic characteristics of strain SH4s T were determined. The GenBank/EMBL/DDBJ accession number for the 16S rRNA gene sequence of strain SH4s T is AM911047. Neighbour-joining and maximum-likelihood 16S rRNA gene sequence- based phylogenetic trees and a two-dimensional thin-layer chromato- gram of the polar lipids of SH4s T are available as supplementary material with the online version of this paper. International Journal of Systematic and Evolutionary Microbiology (2008), 58, 1922–1926 DOI 10.1099/ijs.0.65813-0 1922 65813 G 2008 IUMS Printed in Great Britain