Bacillus indicus sp. nov., an arsenic-resistant bacterium isolated from an aquifer in West Bengal, India

Abstract

Strain Sd/3^T (=MTCC 4374^T=DSM 15820^T), an arsenic-resistant bacterium, was isolated from a sand sample obtained from an arsenic-contaminated aquifer in Chakdah district in West Bengal, India (23° 3' N 88° 35' E). The bacterium was Gram-positive, rod-shaped, non-motile, endospore-forming and yellowish-orange pigmented. It possessed all the characteristics that conform to the genus Bacillus, such as it had A₄β murein type (L-orn-D-Asp) peptidoglycan variant, MK-7 as the major menaquinone and iso-C_15:0 and anteiso-C_15:0 as the major fatty acids. Based on its chemotaxonomic and phylogenetic characteristics, strain Sd/3^T was identified as a species of the genus Bacillus. It exhibited maximum similarity (95%) at the 16S rRNA gene level with Bacillus cohnii; however, DNA-DNA similarity with B. cohnii was 60·7%. Strain Sd/3^T also exhibited a number of phenotypic differences from B. cohnii (DSM 6307^T). These data suggest that Sd/3^T represents a novel species of the genus Bacillus. The name Bacillus indicus sp. nov. is proposed.