Bacillus arsenicus sp. nov., an arsenic-resistant bacterium isolated from a siderite concretion in West Bengal, India

Abstract

Strain Con a/3^T is a Gram-positive, motile, endospore-forming, rod-shaped and arsenic-resistant bacterium, which was isolated from a concretion of arsenic ore obtained from a bore-hole. The bacterium grew in the presence of 20 mM arsenate and 0·5 mM arsenite. Diaminopimelic acid was present in the cell wall peptidoglycan, MK-7 was the major menaquinone, and iso-C_15:0, anteiso-C_15:0, iso-C_16:0 and C_16:1(δ7cis) were the major fatty acids. Based on its phenotypic, chemotaxonomic and phylogenetic characteristics, strain Con a/3^T was identified as a member of the genus Bacillus. It exhibited maximum similarity (97%) at the 16S rRNA gene level with Bacillus barbaricus (DSM 14730^T); however, the DNA-DNA relatedness value with B. barbaricus was 60%. Strain Con a/3^T also exhibited a number of phenotypic differences from B. barbaricus (DSM 14730^T). Strain Con a/3^T was therefore identified as representing a novel species of the genus Bacillus, for which the name Bacillus arsenicus sp. nov. is proposed. The type strain is Con a/3^T (=MTCC 4380^T=DSM 15822^T=JCM 12167^T).