Identification and Characterization of the Effectively Arsenic Tolerant Bacterial Strains from the Potential Arsenic Contaminated Site in 24-Parganas (North) District of West Bengal, India

Arsenic is a common menace in the state of West Bengal particularly in the district of 24-Parganas (North) and (South). The major source of arsenic being geologic in nature. Soil samples collected from one such particular location Baduria were tested for the presence of arsenic (As), and on an average the As content of the soil was 2.18mg/kg. Different bacteria were isolated by serial dilution and were also tested for As tolerance. On the basis of their tolerance, three organisms (viz. C-7, A-2, A-1) have shown remarkable percentage uptake of As 43%, 22.17% and 14% respectively, which was highest for C-7 strain. Azithromycin and Streptomycin were found to be more effective to control C-7 with an inhibition zone of 4.5 cm, but for A- 2 and A-1 it was Azithromycin with inhibition zone of 3.8cm and 3.5cm respectively. These organisms were characterized and identified by 16S rDNA technique, BLAST results and the cluster analysis by NTSYSpc ver. 2.02e program, and found to be Bacillus sp. strain CCBAU 51490 (C-7) (GenBank Accession Number EF377314.1), Bacillus subtilis sub sp. subtilis strain DSM 10 (Genbank Accession Number NR_027552.1) (A-2) and Pseudomonas otidis strain MCC 10330 (Genbank Accession Number NR_043289.1) (A-1). They can be used in the treatment of As contaminated sludge generated industrially from As treatment plant. This can give a new insight in microbial arsenic trapping with minimum toxic implications in the nature.