Tolerance and reduction of chromium by bacterial strains.

Bacteria have potential to tolerate and reduce metals. This study evaluated the potential of selected bacterial strains in tolerating and reducing chromium (Cr). Six bacterial strains (Rhizobium miluonense LCC01, LCC04, LCC05, and LCC69; Rhizobium pusense LCC43; and Agrobacterium deltaense LCC50) showed tolerance to Cr(VI) (16 and 32 µg mL-1), reduction potential of Cr(VI) (from 50 to 80%), and efficiency in producing exopolysaccharides. Rhizobium pusense LCC43 exhibited the highest tolerance (128 µg mL-1), reduction potential of Cr(VI) (from 80 to 100%), and efficiency in producing exopolysaccharides. These results suggested that this strain may have the potential to be used in the bioremediation of soils contaminated with Cr(VI).