Characterization of indigenous bacteria from radon-rich groundwater and their tolerance to physicochemical stress
Radiation exposure and heavy metal (HM) exposure are serious health hazards causing DNA mutation, oxidative damage and may also be responsible for various life-threatening human diseases, while bacteria can withstand such toxicity easily. This study attempted to identify inhabitant bacterial isolates from radon-contaminated groundwater of Tantloi, India, and effort has also been made to characterize their response against radiation, oxidative stress as well as heavy metal tolerance and removal. Total sixteen (16) bacterial isolates were identified as Bacillus spp., Stenotrophomonas spp., Brevibacillus sp., Chryseobacterium sp., Escherichia sp. and Microbacterium sp., which showed less number of distinct carbohydrates utilization potential but high salinity tolerance properties. In addition, Gram-positive Bacillus spp. can tolerate 1 kGy of γ radiation, 10 mM H2O2, 7 days of desiccation and different heavy metals (Cu, Pb, Cr, Zn and As). Four Bacillus spp. and Microbacterium sp., which showed total maximum tolerable concentration (MTC) > 8 out of 5 heavy metals, were considered for their HM removal property analysis. Five multimetal resistance strains had strong removal capacity of Pb and Zn (89–94%) followed by Cr (49–56%) and Cu/As (0.4–22%). This investigation may provide baseline information of radon-contaminated groundwater microbiology, thus could be used to formulate an appropriate strategy for radon and radionuclides remediation.
KeywordsRadon contamination Groundwater γ-Radiation Heavy metal Maximum tolerable concentration (MTC)
The author acknowledges Department of Biotechnology, Govt. of India, for their financial assistance. Authors are thankful to Dr. Abhijit Saha, Centre Director of UGC-DAE Consortium for Scientific Research (Kolkata Centre) for providing Gamma radiation facility. Finally, the technical and experimental support rendered by laboratory members of the Department of Life Science and Biotechnology, Jadavpur University, is gratefully acknowledged with wholesome honesty.
Funding for the fellowship was provided by Department of Biotechnology, Ministry of Science and Technology (Grant No. DBT/2016/JU/732).
- Ashmaig A, Hasan A, El Gaali E (2009) Identification of lactic acid bacteria isolated from traditional Sudanese fermented camels milk (Gariss). Afr J Microbiol Res 3:451–457Google Scholar
- Darby S, Hill D, Auvinen A, Barros-Dios JM, Baysson H, Bochicchio F, Deo H, Falk R, Forastiere F, Hakama M, Heid I, Kreienbrock L, Kreuzer M, Lagarde F, Mäkeläinen I, Muirhead C, Oberaigner W, Pershagen G, Ruano-Ravina A, Ruosteenoja E, Schaffrath Rosario A, Tirmarche M, TomáBek L, Whitley E, Wichmann HE, Doll R (2005) Radon in homes and risk of lung cancer: collaborative analysis of individual data from 13 European case–control studies. BMJ 330:223CrossRefGoogle Scholar
- Rice EW, Baird RB, Eaton AD (2017) Standard Methods for the Examination of Water and Wastewater, 23rd edn. American Public Health Association, American Water Works Association, Water Environment Federation. ISBN: 9780875532875Google Scholar
- WHO (2011) Guidelines for drinking-water quality. Chapter 9. Radiological aspects. 4. World Health Organization, GenevaGoogle Scholar
- Wieben C, Baker RJ, Nicholson RS (2013) Nutrient concentrations in surface water and groundwater, and nitrate source identification using stable isotope analysis in the Barnegat Bay-Little Egg Harbor watershed, New Jersey, 2010–11. US Department of the Interior, US Geological Survey, RestonCrossRefGoogle Scholar