Effect of heavy metals on marine Bacillus sp. and Flavobacterium sp.

: Responses to varying concentrations of Hg, Cd, and Zn were studied in two strains of bacterial isolates (Flavobacterium sp. and Bacillus sp.) from Indian coastal waters. Growth responses showed inhibition (in terms of percentage reduction with respect to control) and the order of inhibition was Hg>Zn>Cd in the case of Bacillus sp. and Hg>Cd>Zn in the case of Flavobacterium sp. With prolonged incubation Bacillus sp. overcame the inhibitory effect whereas Flavobacterium sp. did not. Higher concentrations of glucose in the growth medium increased the inhibitory effect of the metal. At lower concentrations (15μg ml(-1)) there was a stimulatory effect on [(14)C] glucose uptake on Flavobacterium sp. Our studies showed that the Gram positive isolate was less adaptable to metals than the Gram negative.