Bacillus litorisediminis sp. nov., a Thermophilic Bacterium Isolated from Mangrove Sediment

Abstract

Two aerobic, Gram-staining-positive, rod-shaped, endospore-forming, thermophilic bacterial strains, designated FJAT-47801^T and FJAT-47835, were isolated from the sediment collected from Zhangjiang Estuary Mangrove National Nature Reserve in Fujian Province, China. Growth was observed at 25-55 °C (optimum, 50 °C) and pH 7.0-9.0 (optimum, pH 7.0), with up to 4.0% (w/v) NaCl (optimum, without NaCl). Strains FJAT-47801^T and FJAT-47835 showed the highest 16S rRNA gene sequence similarity to Bacillus oleivorans (98.5%). The 16S rRNA gene sequence similarity between FJAT-47801^T and FJAT-47835 was 99.9% indicating they were the same species. Phylogenetic (based on 16S rRNA gene sequences) and phylogenomic (based on 120 conserved bacterial single-copy genes) trees showed that strains FJAT-47801^T and FJAT-47835 should be affiliated to the genus Bacillus. The of menaquinone of strain FJAT-47801^T was MK-7. The major fatty acids of strain FJAT-47801^T were iso-C_15:0, anteiso-C_15:0, iso-C_17:0, and C_16:0. The major polar lipids strain FJAT-47801^T were phosphatidylethanolamine (PE), diphosphatidylglycerol (DPG), and phosphatidylglycerol (PG). The genomic DNA G+C content of strain FJAT-47801^T was 39.3%. The average nucleotide identity (84.3%) and the digital DNA-DNA hybridization value (28.1%) between strain FJAT-47801^T and B. oleivorans CCTCC AB 2013353^T were below the cut-off level for species delineation. Based on the above results, strain FJAT-47801^T represents a novel species of the genus Bacillus, for which the name Bacillus litorisediminis sp. nov., is proposed. The type strain is FJAT-47801^T (=GDMCC 1.2712^T = JCM 34875^T).