Heavy metal resistant bacteria associated with the black clam Villorita cyprinoides var cochinensis (Hanley) and water collected from Cochin backwater

Abstract

A total of 147 strains of heterotrophic bacteria, isolated from water and the black clam Villorlia cyprinoides var conchinensis from Cochin backwater were subjected to heavy metal sensitivity tests for five heavy metals viz. mercury. zinc, cadmium, copper and lead. In general, the isolates from water showed higher resistance towards the heavy metals. Members of all the genera except Coryneform group showed similar trend of resistance. The strains of Coryneform group isolated from animals were more resistant than their counterparts isolated from water. Minimum inhibitory concentration (MIC) of the metals varied. It may be concluded from the results that the habitat of the organisms plays a unique role in the ecology of heavy metal resistant bacteria.