Bio-remediation of acephate-Pb(II) compound contaminants by Bacillus subtilis FZUL-33

Removal of Pb2+ and biodegradation of organophosphorus have been both widely investigated respectively. However, bio-remediation of both Pb2+ and organophosphorus still remains largely unexplored. Bacillus subtilis FZUL-33, which was isolated from the sediment of a lake, possesses the capability for both biomineralization of Pb2+ and biodegradation of acephate. In the present study, both Pb2+ and acephate were simultaneously removed via biodegradation and biomineralization in aqueous solutions. Batch experiments were conducted to study the influence of pH, interaction time and Pb2+ concentration on the process of removal of Pb2+. At the temperature of 25`degrees C, the maximum removal of Pb2+ by B. subtilis FZUL-33 was 381.31 11.46 mg/g under the conditions of pH 5.5, initial Pb2+ concentration of 1300 mg/L, and contact time of 10 min. Batch experiments were conducted to study the influence of acephate on removal of Pb2+ and the influence of Pb?* on biodegradation of acephate by B. subtilis FZUL-33. In the mixed system of acephate-Pb2+, the results show that biodegradation of acephate by B. subtilis FZUL-33 released POI', which promotes mineralization of Pb2+. The process of biodegradation of acephate was affected slightly when the concentration of Pb2+ was below 100 mg/L. Based on the results, it can be inferred that the B. subtilis FZUL-33 plays a significant role in bio-remediation of organophosphorus-heavy metal compound contamination. (C) 2016 The Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V.