Characterization of Arsenic Resistant Bacteria from Shallow Tubewell and Evaluation of their Remediation Capacity

The present study was conducted to characterize arsenic resistant bacteria and to evaluate their arsenic remediation capacity. Water samples were collected from the shallow tubewell of Deganga, West Bengal. The arsenic content of shallow tubewell water was 45.07 μg/L. 16S rDNA analysis characterized the isolated arsenic resistant bacteria from the shallow tubewell water to be under the genus Pseudomonas and Acinetobacter. Minimum inhibition concentration (MIC) of arsenic for the selected bacterial isolates Pseudomonas sp. and Acinetobacter sp. was found to be 7 and 17.5 mM As(III), respectively. The selected bacterial isolates were capable of removing arsenic in the range of 1.54-5.95% from the nutrient broth supplemented with 25, 50, 75 and 100 mg/L As(III). Analysis of variance (ANOVA) indicated a significant difference (P<0.05) in arsenic removal between the arsenic concentrations, but there was no significant difference (P>0.05) between the selected bacterial isolates. The selected bacterial isolates could thus be useful for developing a technology for biological removal of arsenic by standardizing certain parameters for the optimum removal of arsenic by the selected bacterial isolates.