Gamma irradiation in modulating arsenic bioremediation potential of Pseudomonas sp. AK1 and AK9

Abstract

Purpose

Present study deals with the role of gamma irradiation in modulating arsenic bioremediation of Pseudomonas sp. AK1 and AK9 strains

Materials and methods

The bacterial strains AK1 and AK9 of Pseudomonas sp. were irradiated at different doses (5 Gy, 10 Gy, 15 Gy and 20 Gy) of gamma irradiation. The effect of γ-irradiation on the growth and arsenic modulating ability of AK1 and AK9 strains was determined in the presence and absence of arsenic along with non-irradiated strains. Further, a comparative study of non-irradiated and irradiated strains by protein profiling in absence and presence of arsenic was carried out to confirm of the increased expression ofarsenite oxidase.

Results

Both strains were able to transform AsIII to AsV. Both strains AK1 and AK9 decrease the arsenic concentration by 626.68 ppb (13.36%) and 686.40 ppb (14.71%) after an incubation period of 96 h in presence of arsenic. Gamma irradiated AK9 strains showed doubled growth in presence of arsenic as compared to non-irradiated strains at 10 Gy treatment whereas no changes in growth was observed in irradiated AK1 strains. Gamma irradiated AK9 strain decrease 378.65 ppb (7.27%) more arsenic concentration from natural water sample supplemented with AsIII than non-irradiated AK9 strain. Further, in the protein profile, increased expression of arsenite oxidase (∼85 kDa) was observed in irradiated AK9 strains in presence of arsenic.

Conclusions

Overall, the results suggested that the gamma irradiated AK9 strain having potential for arsenic accumulation and increased arsenite tolerance may play a great role in the bioremediation of the arsenite at arsenic contaminated sites.

Keywords:

• Arsenic
• arsenite
• arsenic transforming bacteria
• γ-irradiation
• bioremediation
• bioaccumulation

Acknowledgments

The authors would like to thank the Department of Biotechnology, Central University of South Bihar, Gaya, for providing the laboratory facilities. The authors are also thanks to Dr. Vinita Trivedi and Dr. Arun Kumar for providing facilities for the irradiation with Cobalt-60 machine at Mahavir Cancer Sansthan, Phulwari sharif, Patna, Bihar. The authors also thank Dr. Pradhan Parth Sarthi for facilitating the use AAS at Dept. of Environmental Sciences of Central University of South Bihar, Gaya, Bihar, India.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

The author(s) reported there is no funding associated with the work featured in this article.

Notes on contributors

Ghanshyam K Satyapal

Dr. Ghanshyam K Satyapal is an Assistant Professor at the Department of Zoology, Veer Knar Singh University, Ara, Bihar, India. He has published more than five research articles in leading international and national journals. He has a wide area of research experience in the field of microbiology and bioremediation.

Rizwanul Haque

Prof (Dr.) Rizwanul Haque is a Senior Professor at the Department of Biotechnology, Central University of South Bihar, Gaya, India. He has published more than 50 research articles in leading international and national journals. He has a wide area of research experience in the field of immunology particularly on stem cells to treat immune-mediated diseases.

Nitish Kumar

Dr. Nitish Kumar is a Senior Assistant Professor at the Department of Biotechnology, Central University of South Bihar, Gaya, India. He has published more than 70 research articles in leading international and national journals. He has a wide area of research experience in the field of agricultural biotechnology and bioremediation.