Enhanced chromate reduction by resting Escherichia coli cells in the presence of quinone redox mediators.
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.
Liu
Guangfei
G
Key Laboratory of Industrial Ecology and Environmental Engineering, Ministry of Education, Dalian University of Technology, Dalian 116024, China.
Yang
Hua
H
Wang
Jing
J
Jin
Ruofei
R
Zhou
Jiti
J
Lv
Hong
H
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*
D002840:Chromates; D008670:Metals; D009285:Naphthoquinones; D011809:Quinones; D005947:Glucose; C005090:lawsone