Studies on bioremoval of copper and zinc by Desulfovibrio desulfuricans isolated from Chitradurga mine sites, India

This paper reports the study on the feasibility of bioremoval of copper and zinc using sulphate reducing bacteria (Desulfovibrio desulfuricans) grown on low cost carbon sources like rice husk, saw dust and manure. Efficient growth of wild strain was achieved with all the low-cost carbon substrates. The inhibition effect of copper and zinc sulphate on the growth of D. desulfuricans cells was established and was found to be concentration dependent. 25 ppm Cu(II) and 30 ppm Zn(II) ions were able to completely inhibit the growth of cells. Strains tolerant to higher metal ion concentrations were obtained by serial subculturing and used for bioremoval studies. Direct bioremoval of copper and zinc during the growth was achieved for all the strains. Strains grown in presence of rice husk had higher bioremoval efficiency with percent removal of nearly 72% and 86% for 500 ppm of initial copper and zinc concentration respectively.