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[en] Heavy metal pollution affects environment adversely and leads to severe implications for both flora and fauna. In the present work, bacterial strain JS-1 was isolated with tolerance for different metals such as mercury (Hg), lead (Pb), cadmium (Cd), nickel (Ni), arsenic (As), tin (Sn), selenium (Se), zinc (Zn), chromium (Cr) and copper (Cu). JS-1 showed a significant tolerance for mercuric chloride (up to 5,000 lg/g) along with an efficient metal uptake and transformation. Growth of JS-1 was marginally affected on exposure to high mercury concentration due to acclimatization of the culture towards mercury. No mercury was found in cell-free supernatant after 96 h of incubation with 500 µg/g and 1,000 lg/g of mercury as an active ingredient. Almost all the mercury was found associated with cell biomass as determined by hydride generation atomic absorption spectroscopy. Only 60 % of mercury was sequestered in bacterial biomass on exposure to 2,000 and 5,000 µg/g mercury. As a detoxification mechanism, nearly 5 % of sequestered mercury was volatilized by the selected isolate (JS-1). Further X-ray diffraction analysis of deposited silvery grey biomass confirmed biotransformation of sequestered mercuric ions into monovalent mercury (Hg2Cl2), a non-bioavailable form of mercury. Culture was characterized morphologically, physiologically and biochemically. 16S rRNA gene sequence of JS-1 revealed its phylogenetic relationship and 98 % homology with Alcaligenes faecalis, a Gram-negative rod-shaped bacterium.