Mercury Resistant Bacterial Population and Characterization of Bacillus sp., Isolated From Sediment of Solid Waste Discharged Point of Steel Industry

摘要

Most of the soil bacteria which are continuously exposed to mercury present in soil and sediments of lakes and rivers have genetically adapted to resist its toxicity. In the present study, mercury resistant bacterial population was enumerated from sediment samples of Rourkela Steel Plant, Odisha and a highly mercury resistant strain (MIC = 100 ppm), identified as Bacillus sp., was characterized by various biochemical tests. Mercury levels in the collected sediments were in the range of 0.054-0.079 ppm. Percentages of mercury resistant bacteria in sediments at four sites were 42, 26.32, 67.56, 83.93 % respectively. The highly resistant strain Bacillus sp. could grow well with 7 and 8 pH, 45 A degrees C temperature and 6 ppt NaCl concentration. MIC of Zn, Cu, Fe and Cd are 40, 40, 40 and 20 ppm respectively. The isolate Bacillus sp. SD-43 which has shown greater tolerance of mercury besides volatilizing 60.06 % of mercury as HgCl2 is attributed to the adaptation towards various stress conditions and may be potentially utilized in the process of bioremediation of mercury in contaminated area.