Removal of Cadmium by <em>Halobacterium </em> strain R1 MTCC 3265 from saline and non-saline econiches

Abstract

Haloarchaeon <em>Halobacterium </em> strain R1 MTCC 3265 is an attractive candidate for use in bioremediation due to its resistance to 4 mM cadmium (Cd) in nutrient rich medium NTYE (25% NaCl Tryptone Yeast extract) and up to 2 mM Cd in synthetic medium NGSM (20% NaCl glucose synthetic medium) containing 0.2% glucose as sole source of carbon. The cells accumulated a maximum of 18 ppm of Cd on the 5^th day of growth. In line with its true haloarchaeal nature the cells of <em>Halobacterium </em> strain R1 lysed on suspension in distilled water or media containing low NaCl concentrations. As such this strain cannot be used for the removal of metal from non-saline environments. However to overcome this problem cells were immobilised in calcium alginate. The immobilized cells were viable and could efficiently remove up to 63% Cd from deionized water.