Bacterial interactions with chromate.

Hexavalent chromium compounds (chromates and dichromates) are highly toxic and are considered as mutagens and carcinogens. These compounds are discharged frequently to the environment as a result of diverse industrial processes. Some microorganisms are able to reduce hexavalent chromium to the less toxic trivalent form. Chromate pollution has promoted the selection of bacterial strains possessing chromate resistance determinants, usually carried by plasmids. Strains combining both abilities, i.e. resistance to and reduction of chromate, are potentially useful for detoxifying chromate polluted waste waters.