Heavy Metal Removal by Magnetospirillum Strains and Its Possible Use in the Treatment of Tannery Effluents

Abstract

Heavy metals are a threat to the sustainable environmental condition causing ecological imbalance. MTBs utilize iron via a metal transport system known as biomineralization Therefore, the strains MSR-1, RJS2, RJS5, RJS6, and RJS7 were exposed to (1,10 ppm) Cd, Mn, Pb, Ni, Zn, Cr, and Co as a sole electron donor, and time/days for efficient biosorption were optimized. The AAS analysis revealed that the RJS2 strain showed maximum biosorption (1 ppm) of Pb (96%). The strains MSR-1, RJS5, RJS6, and RJS7 produced biosorption of all metals. Biosorption by MSR-1 was more at 10 ppm. However, the RJS5 strain displayed better sorption properties against Pb (93.42%) at 50 ppm. Further exposure of strains against metal biosorption from tannery effluents yielded RJS6 [nickel (88%) and zinc (81%)] and RJS2 [manganese (82%) and cobalt (96%)] as potent strains. The heavy metal removal in MTBs can be further explored on an industrial scale.