Bacillus ligniniphilus sp nov., an alkaliphilic and halotolerant bacterium isolated from sediments of the South China Sea

An alkaliphilic and halotolerant Gram-stain-positive bacterium, which was isolated from sediment samples from the South China Sea, was subjected to a taxonomic study. The isolate, strain L1(T), grew well at a wide range of temperatures and pH values, 10.0-45.0 degrees C and pH 6-11, with optima at 30 degrees C and pH 9.0, respectively. The growth of strain LIT occurred at total salt concentrations of 0-10% (w/v) with an optimum at 2% (w/v). Phylogenetic analysis based on 16S rRNA sequence comparison indicated that the isolate represented a member of the genus Bacillus. The strains most closely related to strain L1(T) were Bacillus nanhaiisediminis JCM 16507(T), Bacillus halodurans DSM 497(T) and Bacillus pseudofirmus DSM 8715(T), with 16S rRNA similarities of 96.5 %, 95.9% and 95.7%, respectively. DNA DNA hybridization of strain L1(T) with the type strains of the most closely related species, B. nanhaiisediminis JCM 16507(T), B. halodurans DSM 497(T) and B. pseudofirmus DSM 8715(T), showed reassociation values of about 21.7%, 14.3% and 13.9 %, respectively. The DNA G+C content of strain L1(T) was 40.76 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 L1(T) were iso-C-14:0, and anteiso-C-15:0. The major polar lipids were diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylglycerol. Based on the phenotypic and phylogenetic characteristics, it is proposed that strain L1(T) (=JCM 18543(T)=DSM 26145(T)) should be classified as the type strain of Bacillus ligniniphilus sp. nov.