Bacillus ectoiniformans sp. nov., a halotolerant bacterium isolated from deep-sea sediments.

Abstract

A halotolerant, Gram-positive bacterium (strain NE-14T), which was isolated from sediment samples of the South China Sea, was subjected to a taxonomic study. Strain NE-14T grew well at wide temperature and pH ranges, 10.0-45.0 °C and pH 6-10, with an optimum at 30 °C and pH 8.0, respectively. Growth of strain NE-14T was observed at total salt concentrations of 0-10 % (w/v) with optimum at 2 % (w/v). Phylogenetic analysis based on 16S rRNA gene sequence comparison indicated that the isolate belongs to the genus Bacillus. Strain NE-14T was related most closely to Bacillus shackletonii LMG 18435T, Bacillus bataviensis LMG 21833T, Bacillus idriensis SMC 4352-2T and Bacillus drentensis LMG 21831T with 16S rRNA gene sequence similarities of 96.2, 95.9, 95.8 and 95.7 %, respectively. DNA-DNA hybridization between strain NE-14T and B. shackletonii LMG 18435T, B. bataviensis LMG 21833T, B. idriensis SMC 4352-2T and B. drentensis LMG 21831T gave reassociation values of about 27.4, 22.4, 16.4 and 15.9 %, respectively. The DNA G+C content of strain NE-14T was 39.2 mol%. The predominant isoprenoid quinone was menaquinone 7 (MK-7). The cell-wall peptidoglycan contained meso-diaminopimelic acid as the diagnostic diamino acid. The predominant cellular fatty acids of strain NE-14T were iso-C15 : 0 and anteiso-C15 : 0. The major polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol and phospholipid. Based on the phenotypic and phylogenetic characteristics, it is proposed that strain NE-14T be classified as representing a novel species of the genus Bacillus, for which the name Bacillus ectoiniformans sp. nov. is proposed. The type strain is NE-14T ( = DSM 28970T = JCM 30397T).