Metal-Tolerating ability of some selected Rhizobia strains
Heavy-metal pollution from many industrial processes is a major threat to human health and the environment resulting in loss of farming and grazing land. Many bacterial strains have been reported to tolerate metals but there is a dearth of research on the metal-tolerating ability of rhizobia strains, hence the need for this study to screen selected Rhizobial strains for their ability to tolerate varying concentrations of selected heavy metals. Ten Rhizobia strains including Bradhyrhizobium japonicum strains FA3, UDSA136, USDA 9032, USDA110, RANI 22, USDA 4675, RAUG and Bradhyrhizobium sp. strains B574, R25B and USDA 3541 obtained from the culture collection of the International Institute of Tropical Agriculture (IITA) were used for this study. They were screened for their ability to tolerate varying concentrations (10-150 μg/mL) of six selected metals (Copper, Cobalt, Cadmium, Lead, Zinc and Iron) on metal-incorporated Congo-red medium. FA3 (Bradhyrhizobium japonicum) showed the highest tolerance to iron (100 μg/mL), while FA3, USDA110 and USDA 4675 showed highest resistance to zinc with Minimum Inhibitory Concentration (MIC) of 150 μg/mL. Strains USDA 3451, USDA 4675, B547 were unable to grow on the cobalt-incorporated medium, while strains RAUG 1, USDA 4675, USDA136 and R25B had the highest MIC of 150 μg/mL for lead. Copper was the most toxic to the Rhizobial strains as the MIC recorded was between 10-20 μg/mL, while all the strains were able to tolerate 150 μg/mL concentration of Cadmium. Rhizobial strains could find a use in the bioremediation and recovery of soils contaminated with heavy metals as shown by their potentials to tolerate certain degree of metal concentration in this study.
Arora, N. K., Khare, E., Singh, S., Maheshwari D. K. (2010). Effect of Al and heavy metals on enzymes of nitrogen metabolism of fast and slow growing rhizobia under explanta conditions. World Journal of Microbiology and Biotechnology. 26, 811–816.
Chasapis, T. C., Loutsidou, C. A., Spillopoulou A. C., Stefanidou, E. M. (2012). Zinc and human health: an update. Archives of Toxicology. 86, 521-534.
Czarnak K., Terpilowska S., Siwicki K. A. (2015). Selected aspects of the action of cobalt ions in the human body. Central European Journal of Immunology. 40: 236-242.
Cui, W. T., Gao, C. Y., Fang, P., Lin, G. Q., and Shen, W. B. (2013). Alleviation of Cadmium toxicity in Medicago sativa by hydrogen-rich water. Journal of Hazardous Materials. 260: 715–724.
El-Aziz, R., Angle, J. S., and Chaney, R. L. (1991). Metal tolerance of Rhizobium meliloti isolated from heavy-metal contaminated soils. Soil Biology and Biochemistry. 23, 795-798.
Godt, J., Scheidig, F., Groneberg, D. A., Grosse-Siestrup, C., Esche, V., Brandenburg, P., Reich Andrea, R., Groneberg, D. A. (2006). The toxicity of Cadmium and the resulting harzards for human health. Journal of Occupational Medicine and Toxicology. 22, 1-6.
Gupta, C. P. (2014). Role of Iron (Fe) in Body. Journal of Applied Chemistry.7, 38-46.
Jin, Q. J., Zhu, K. K., Cui, W. T., Xie, Y. J., Han, B., and Shen, W. B. (2013). Hydrogen gas acts as a novel bioactive molecule in enhancing plant tolerance to paraquat-induced oxidative stress via the modulation of heme oxygenase-1 signalling system. Plant Cell Environment. 36, 956–969.
Kulshresh, A., Agrawal, R., Barar, M., Saxena, S. (2014). A review on Bioremediation of heavy metal in contaminated water. Journal of Environmental Science, Toxicology and Food Technology. 8, 44-50.
Manju, M. (2015). Effect of heavy metals on human health. International Journal of Research granthaalayah. pp1-7.
Narasimhulu, K. and Setty Y. P. (2012). "Biosorption of copper from wastewater by Bacillus subtilis in packed bed bioreactor." Journal of Biodiversity and Environmental Science (JBES). 2, 23-30.
Pazirandeh, M, Wells, B. M and Ryan, R.,L (1998). Development of bacterial based heavy metal biosorbents: enhanced uptake of Cadmium and Mercury by E.Coil expressing a binding motiff. Applied Environmental Microbiology. 64, 4068
Pereira, L. B, Tabaldi, L. A, Lucena, J. J, Goncalves, J. F, Jucoski, G. O., Pauletto, M. M, Weis, S. N, Nicoloso, F. T., Borher, D., Rocha, J. B. T, Schetinger, M. R. C (2006). Effect of Aluminium on δ-aminolevulinc acid dehyratase (ALA-D) and the development of cucumber (Cucumis sativus). Environmental experimental Botany 57, 106-115.
Rajendra, P., Muthukrishan, J. and Gunasekaran, P. (2003). Microbes in heavy Metal remediation. Indian Journal of Experimental Biology 41, 935-944.
Strong, P. J. and Burgess, J. E., (2008). Treatment methods of wine-related and distillery wastewater: a review, Bioremediation Journal. 12, 70-87.
Singh, R.., Singh, P. and Sharma, R. (2014). Microorganism as a tool of bioremediation technology for cleaning environment: A review. International Academy of Ecology and Environmental Science, 4, 1-6.
Teng, Y., Wang, L., Li, Z. and Luo, Y. (2015). Rhizobia and their bio-partners as novel drivers for functional remediation in contaminated soils. Frontiers in plant science 6, 1-11.
Tiwari, S., Tripathi, I. P. and Tiwari, H. I. (2013). Effects of Lead on Environment. International journal of emerging research in management & technology. 2, 1-6.
Valentín, L., Nousiainen, A. and Mikkonen, A. (2013). “Introduction to organic contaminants in soil: concepts and risks,”in Emerging Organic Contaminants in Sludges: The Handbook of Environmental Chemistry, eds A.G.Kostianoy and D. Barceló (Berlin, Heidelberg: Springer-Verlag), 1–29.
Younis, M. (2007). Responses of Lablab purpureus-Rhizobium symbiosis to heavy metals in pot and field experiments. World Journal of Agricultural Science. 3, 111–122.