Bioremediation of cadmium by growing Rhodobacter sphaeroides: kinetic characteristic and mechanism studies.
The removal kinetic characteristic and mechanism of cadmium by growing Rhodobacter sphaeroides were investigated. The removal data were fitted to the second-order equation, with a correlation coefficient, R2=0.9790-0.9916. Furthermore, it was found that the removal mechanism of cadmium was predominantly governed by bioprecipitation as cadmium sulfide with biosorption contributing to a minor extent. Also, the results revealed that the activities of cysteine desulfhydrase in strains grown in the presence of 10 and 20 mg/l of cadmium were higher than in the control, while the activities in the presence of 30 and 40 mg/l of cadmium were lower than in the control. Content analysis of subcellular fractionation showed that cadmium was mostly removed and transformed by precipitation on the cell wall.
Bai
Hong-Juan
HJ
School of Chemical Engineering and Environment, North University of China, Taiyuan 030051, PR China. bhj44871@163.com
Zhang
Zhao-Ming
ZM
Yang
Guan-E
GE
Li
Bao-Zhen
BZ
D000327:Adsorption; D000332:Aerobiosis; D001673:Biodegradation, Environmental; D019149:Bioreactors / Q000382:microbiology; D002104:Cadmium / Q000032:analysis / Q000378:metabolism*; D002473:Cell Wall / Q000378:metabolism; D011232:Chemical Precipitation; D003542:Cystathionine gamma-Lyase / Q000032:analysis / Q000378:metabolism; D007700:Kinetics; D012242:Rhodobacter sphaeroides / Q000201:enzymology / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D012995:Solubility; D013347:Subcellular Fractions / Q000378:metabolism; D013440:Sulfides / Q000378:metabolism; D014961:X-Ray Diffraction
D013440:Sulfides; D002104:Cadmium; D003542:Cystathionine gamma-Lyase