Bacillus silvicola sp. nov., a new species within the Bacillus cereus group isolated from hardwood forest soil in Maryland, USA

Abstract

Abstract A single bacterial strain, IBL03679 T , from forest soil in Maryland, USA in 2009 was originally identified as belonging to the Bacillus cereus senso lato group through multi-locus sequence analysis. Here, further identification efforts with genomic and phenotypic methods demonstrate that this strain belongs to a new species. Phylogenetic analysis using whole-genome sequencing suggested the most closely related species is Bacillus proteolyticus . ANIb and dDDH values confirmed species differentiation with values below conventional 95–96% and 70% thresholds, respectively. Genomic comparisons with five other Bacillus strains with the same sequence type also group into the proposed species nov. It is a gram-stain positive, facultative anaerobe, endospore and parasporal crystal forming rod-shaped bacterium. Physiological characteristics, such as casein hydrolysis and lecithinase production, and major fatty acids identified (C 16:0 , iso-C 15:0 , and iso-C 17:0 ), support affiliation with other Bacillus species. The polar lipid profile was primarily diphosphatidylglycerol (DPG), phosphatidylethanolamine (PE), and phosphatidylglyercol (PG); the peptidoglycan type was A1γ meso-Dpm – direct (A31); and the sole respiratory quinone was menaquinone-7. Biochemical testing revealed distinguishing test results for strain IBL03679 T through inability to metabolize D-cellobiose and D-saccharose, and utilization of potassium gluconate. Collectively, the genotypic and phenotypic data demonstrate that IBL03679 T belongs to a novel species. We propose the name Bacillus silvicola sp. nov. for this taxon with the type strain IBL03679 T (= NRRL B-65743 T , = CCUG 78293 T ).