Abstract
The hypothesis that mercury-resistant bacteria exposed to polluted environments such as coastal areas can tolerate, detoxify, or biotransform a variety of other toxicants was examined. Several mercury-resistant marine bacteria from the coastal waters of India were evaluated for their ability to biotransform the heavy metals mercury, cadmium and lead as well as xenobiotics like polychlorinated biphenyls and tributyltin. These salt-tolerant bacteria removed mercury by means of volatilization and were successfully used to detoxify mercury-amended growth medium for the culturing of mercury-sensitive Phormidium sp. Over 70% cadmium and 95% of the lead from the growth medium were either cell-bound (cadmium) or precipitated (lead) by some of these bacteria. A pseudomonad strain, CH07, aerobically degraded fourteen toxic polychlorinated biphenyls including congeners with five or more chlorine atoms on the biphenyl ring and was also equally efficient in degrading more than 54% of the tributyltin. These bacteria offer great biotechnological opportunities in the bioremediation of toxic chemicals.
