Isolation and characterization of arsenic-resistant bacteria from contaminated water-bodies in West Bengal, India

Bengal Basin is known for severe arsenic contamination. In the present study, we have isolated six bacteria from the arsenic contaminated surface water of Bengal Basin. 16S rDNA sequence analysis identified them as <i>Microbacterium oleivorans</i>, <i>Acinetobacter soli</i>, <i>Acinetobacter venetianus</i>, <i>Acinetobacter junii</i>, <i>Acinetobacter baumannii</i>, <i>Acinetobacter calcoaceticus</i>. All the isolates possess arsenic accumulation potential and high molecular weight plasmid (&gt;10 kb). PCR amplification indicated the presence of arsenic-resistance genes (<i>arsB</i> and <i>aoxB</i>) either in the genome or plasmid or in both in the isolated bacteria (except in <i>Acinetobacter venetianus</i>). Exposure to arsenic affected bacterial growth and induced alteration in cytoplasmic membrane integrity.