Arsenic Bioremediation Potential of Arsenite-Oxidizing Micrococcus sp. KUMAs15 Isolated from Contaminated Soil

Environmental arsenic(As) contamination,considered as the largest mass poisoning of the human population,has become a serious health concern for the people of South East Asia,including those living in the Bengal delta.An As-resistant strain,KUMAs15,was isolated from the As-contaminated fields in Nadia Ddistrict in West Bengal,India and was evaluated for its possible use in environmental As bioremediation.Molecular identification based on 16S rDNA gene sequencing revealed that the strain belonged to the genus Micrococcus.The strain tolerated high levels of As and oxidized arsenite under the culture condition.The strain also accumulated large quantities of As when exposed to a wide range of environmentally relevant concentrations of inorganic As.Analysis of the aoxB,arsB,and arsC gene expression explained the underlying cause of arsenite oxidation and As accumulation by KUMAs15.The As-resistant strain KUMAs15 of Micrococcus sp.was suggested to be a potential environmental As decontaminant.