Management of chromium induced oxidative stress by marine Bacillus licheniformis

The present study describes management of oxidative stress induced by heavy metal chromium in marine Bacillus licheniformis (NCBI GenBank Accession NumberHM194725). It is identified that the isolate reduces 10-1500 mg/L of Cr (VI) within 24-72 h. Existence of chromium reductase in growth medium implies the possibility of enzymatic reduction of Cr (VI) to Cr (III). Nevertheless, no correlation was observed between the real concentration of Cr (III) and the predicted concentration upon reduction of Cr (VI). Extracellular surface-active agent (biosurfactant) of the isolate was found responsible for the reduced level of Cr (III) in the solution which eventually provides tolerance to the cells towards hexavalent chromium and protects the cells from oxidative stress.