Screening and Characterization of Chromium Tolerant Bacterial Strains from Electroplating Effluent Contaminated Soil

摘要

The activities of electroplating and metal processing industries are regarded as one of the major sources of heavy metal pollution. Removal of heavy metals from contaminated sites using microorganisms is a cheaper alternative technology. This present study is focused on screening and characterization of chromium tolerant bacterial strains from the electroplating effluent contaminated soil sample. The chromium containing electroplating effluent sample was collected and analyzed for various physicochemical parameters. Sixteen bacterial strains were isolated and identified based on morphological and biochemical characteristics. All the sixteen bacterial strains were screened for metal tolerance using nutrient agar medium incorporated with chromium metal (100 mg/L). Based on the screening study, only six bacterial strains were selected as potential metal tolerant strains and they were characterized with the various environmental conditions viz., pH (pH 5, pH 7 and pH 9), temperatures (5°C 28°C, 37°C and 45°C) and with different metal concentrations (100 mg/L, 200 mg/L, 300 mg/L and 400 mg/L). Among the six bacterial isolates characterized, Pseudomonas spp strain 1 was found to be better chromium resistant organism.