Reduction of hexavalent chromium by Pannonibacter phragmitetus LSSE-09 stimulated with external electron donors under alkaline conditions.
A novel Cr (VI) resistant bacterial strain LSSE-09, identified as Pannonibacter phragmitetus, was isolated from industrial sludge. It has strong aerobic and anaerobic Cr (VI)-reduction potential under alkaline conditions. At 37 °C and pH 9.0, growing cells of strain LSSE-09 could completely reduce 100 and 1000 mg L(-1) Cr (VI)-Cr (III) within 9 and 24h, respectively under aerobic condition. Resting cells showed higher anaerobic reduction potential with the rate of 1.46 mg g(-1)((dry weight))min(-1), comparing with their aerobic reduction rate, 0.21 mg g(-1)min(-1). External electron donors, such as lactate, acetate, formate, pyruvate, citrate and glucose could highly increase the reduction rate, especially for aerobic reduction. The presence of 3000 mg L(-1) acetate enhanced anaerobic and aerobic Cr (VI)-reduction rates up to 9.47 mg g(-1)min(-1) and 4.42 mg g(-1)min(-1), respectively, which were 5 and 20 times faster than those without it. Strain LSSE-09 retained high activities over six batch cycles and NO(3)(-) and SO(4)(2-) had slightly negative effects on Cr (VI)-reduction rates. The results suggest that strain LSSE-09 has potential application for Cr (VI) detoxification in alkaline wastewater.
Key Laboratory of Green Process and Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China.
Lin
L
Xu
Mingfang
M
Luo
Wangliang
W
Li
Xuetuan
X
Wei
Keng
K
Xie
Lijun
L
Liu
Chengying
C
Jiang
Huizhou
H
Liu
D000468:Alkalies / Q000378:metabolism*; D002857:Chromium / Q000378:metabolism*; D004583:Electrons; D006863:Hydrogen-Ion Concentration; D010084:Oxidation-Reduction; D020560:Proteobacteria / Q000378:metabolism*
D000468:Alkalies; D002857:Chromium