title: Enhanced chromate reduction by resting Escherichia coli cells in the presence of quinone redox mediators.
abstract: The reduction of Cr(VI) by resting Escherichia coli cells was significantly enhanced by the quinone redox mediators, lawsone, menadione, anthraquinone-2-sulfonate and anthraquinone-2,6-disulfonate. In the presence of 0.2 mM lawsone, over 97.5% Cr(VI) (100 mg l(-1)) was reduced in 4h. The mediated reduction occurred at initial Cr(VI) concentrations of 50-250 mg l(-1), and increased with increasing initial biomass concentrations from 0.05 to 1.2 g l(-1). The addition of glucose as electron donor promoted the reduction process. Cu(2+), Ni(2+) and Co(2+) inhibited, whereas Mn(2+) and Pb(2+) stimulated reduction. Four rounds of mediated reduction were completed in 19 h, suggesting its stability and persistence. The efficient mediated microbial reduction of Cr(VI) is promising for rapid anaerobic removal of chromate.
authors.affiliation: Key Laboratory of Industrial Ecology and Environmental Engineering, Ministry of Education, Dalian University of Technology, Dalian 116024, China.
authors.forename: Guangfei
authors.initials: G
authors.lastname: Liu
authors.forename: Hua
authors.initials: H
authors.lastname: Yang
authors.forename: Jing
authors.initials: J
authors.lastname: Wang
authors.forename: Ruofei
authors.initials: R
authors.lastname: Jin
authors.forename: Jiti
authors.initials: J
authors.lastname: Zhou
authors.forename: Hong
authors.initials: H
authors.lastname: Lv
mesh_terms: D001673:Biodegradation, Environmental / Q000187:drug effects; D018533:Biomass; D002840:Chromates / Q000378:metabolism*; D004926:Escherichia coli / Q000166:cytology* / Q000378:metabolism*; D005947:Glucose / Q000494:pharmacology; D008670:Metals / Q000494:pharmacology; D009285:Naphthoquinones / Q000494:pharmacology; D010084:Oxidation-Reduction / Q000187:drug effects; D011809:Quinones / Q000494:pharmacology*
chemical_list: D002840:Chromates; D008670:Metals; D009285:Naphthoquinones; D011809:Quinones; D005947:Glucose; C005090:lawsone