Biotransformation of Hexavalent Chromium by Acinetobacter iwofii

In the present study, bio reduction of hexavalent Chromium, a transition metal, known for its high solubility and carcinogenicity, using a sewage isolate was tested under controlled laboratory conditions. The objective of the study included determination of the extent of bio degradation of Cr[VI] by the isolate, characterization of the isolate and testing the degradation potential of the isolate under variable conditions of PH and temperature.The bacterial isolate was identified to be a Gram negative coccobacillus, Acinetobacter iwofii which shows the capacity to reduce Cr[VI]at concentration as high as 60 ppm at a temperature of 550 C and PH ranging from 6-8 in aerobic conditions. Confluent growth was observed along with reduction of Cr[VI]at 370 C ; however, reduction was greater at 550 C Due to its ability to reduce Cr[VI] the organism shows a considerable potential for use in biotransformation studies involving Cr[VI] contamination.The reduction potential of the isolate was comparable to the reduction potential of the consortia reported previously. However, the relatively low potential to detoxify the environment of Cr[VI] by the isolate, may be enhanced by using it in a consortium with other potential chromate reducers.