Metabacillus harenarius sp. nov., an alginate lyase-producing bacterium, and reclassification of 'Bacillus weihaiensis'.

A Gram-stain-negative, motile, rod-shaped, alginate lyase-producing bacterium, designated HB246100T, was isolated from coastal sand sample collected from Luhuitou Scenic Area, Sanya, China. The strain grew at 15-50 ℃ (optimum, 35 ℃), pH 6.0-11.0 (optimal, pH 8.0) and 0-10% (w/v) NaCl (optimum, 3%). The predominant isoprenoid quinone was found to be menaquinone 7, and the major fatty acids were anteiso-C15 : 0, iso-C15 : 0, iso-C14 : 0 and iso-C16 : 0. The polar lipids contained diphosphatidylglycerol, phosphatidylglycerol, an unidentified aminophospholipid, an unidentified lipid, three unidentified phospholipids and three unidentified glycolipids. The size of the genome was 4.29 Mbp, with a G+C content of 36.5 mol%. Phylogenetic analysis of 16S rRNA gene sequences indicated that strain HB246100T belonged to the genus Metabacillus, and the closest phylogenetically related type species were Metabacillus crassostreae JSM 100118T, Metabacillus schmidteae Marseille-P9898T, Metabacillus halosaccharovorans E33T and Metabacillus litoralis SW-211T with the identities of 98.9, 98.1, 98.0 and 98.0%, respectively. The phylogenetic tree based on 16S rRNA gene sequences and the phylogenomic tree based on core genome sequences indicated that the novel strain was most closely related to M. crassostreae and M. litoralis, with average nucleotide identity of 74.8-75.6% and digital DNA-DNA hybridization value of 22.1-22.4%. Comprehensive phenotypic, phylogenetic and genomic characteristics demonstrate that strain HB246100T is distinct from the species with validly published names in the genus Metabacillus, suggesting that it represents a novel species of the genus Metabacillus and proposing the name Metabacillus harenarius sp. nov. The type strain is HB246100T (=MCCC 1K09923T=JCM 38130T). Furthermore, 'Bacillus weihaiensis' Alg07, which only publicly disclosed its genome sequence, was emended and reclassified as M. harenarius.