Resistance and bioaccumulation of Cd 2+ , Cu 2+ , Co 2+ and Mn 2+ by thermophilic bacteria, Geobacillus thermantarcticus and Anoxybacillus amylolyticus

Abstract

In this study, bioaccumulation and heavy metal resistance of Cd 2+ , Cu 2+ , Co 2+ and Mn 2+ ions by thermophilic Geobacillus thermantarcticus and Anoxybacillus amylolyticus was investigated. The bacteria, in an order with respect to metal resistance from the most resistant to the most sensitive, was found to be Mn 2+ > Co 2+ > Cu 2+ > Cd 2+ for both G. thermantarcticus and A. amylolyticus. It was determined that the highest metal bioaccumulation was performed by A. amylolyticus in Mn 2+ (28,566 μg/g dry weight), and the lowest metal bioaccumulation was performed by A. amylolyticus in Co 2+ (327.3 μg/g dry weight). The highest Cd 2+ capacities of dried cell membrane was found to be 36.07 and 39.55 mg/g membrane for G. thermantarticus and A. amylolyticus, respectively, and the highest Cd 2+ capacities of wet cell membrane was found to be 14.36 and 12.39 mg/g membrane for G. thermantarcticus and A. amylolyticus, respectively. © Springer-Verlag Berlin Heidelberg and the University of Milan 2013.