Hexavalent Chromium Reduction by Microbacterium oleivorans A1: A Possible Mechanism of Chromate -Detoxification and -Bioremediation

Title:Hexavalent Chromium Reduction by Microbacterium oleivorans A1: A Possible Mechanism of Chromate -Detoxification and -Bioremediation

Volume: 9 Issue: 2

Author(s): Angana Sarkar, Pinaki Sar and Ekramul Islam

Affiliation:

Keywords: Bioremediation, bacteria, chromium, Cr⁶⁺ biotransformation, Microbacterium oleivorans, heavy metals.

Abstract: Background: Hexavalent chromium (Cr⁶⁺) contamination is one of the mejor problems of environmental protection for its carcinogenic effect on human health. Remediation of Cr⁶⁺ contaminated environment thus becomes highest priority.

Methods: A Gram positive tiny rod shaped chromate (Cr⁶⁺) reducing bacterium strain A1 was isolated from uranium ore collected from Jaduguda, East Singhbhum, Jharkhand. The strain was identified and characterized in terms of its potential to reduce more toxic Cr⁶⁺ to its less toxic form for its application in bioremediation of Cr⁶⁺ contaminated environments.

Results: 16S rRNA gene based phylogentic analysis identified the strain as Microbacterium oleivorans. Along with Cr⁶⁺, the strain showed resistance to other heavy metals including Ag, Cu, Co, Hg, Ni and Zn also. Complete reduction of Cr⁶⁺ (750 µM) was achieved within 84 h with optimum reduction at pH 9 and 30°C. Effect of different parameters including cell mass concentration, pH, induction with Cr⁶⁺, SO₄ ⁼ ion, heavy metals, etc. on Cr⁶⁺ reduction were studied thoroughly at resting cell condition to study its potential towards Cr⁶⁺ bioremediation. Chromate reductase gene (chrA) was detected within this strain.

Conclusion: Along with presence of appropriate genetic determinant, efficient Cr⁶⁺ reduction ability of the strain indicated its potential for developing redox based Cr⁶⁺ remediation system for varied concentrations of Cr6+ under a wide range of environmental conditions. Patent data have suggested the efficient application of Cr⁶⁺ reducing bacteria in cleaning up of Cr⁶⁺ contaminated environments..

Cite this article as:

Sarkar Angana, Sar Pinaki and Islam Ekramul, Hexavalent Chromium Reduction by Microbacterium oleivorans A1: A Possible Mechanism of Chromate -Detoxification and -Bioremediation, Recent Patents on Biotechnology 2015; 9 (2) . https://dx.doi.org/10.2174/187220830902160308192126