cadmium;
genetically engineered Escherichia coli;
bioaccumulation;
heavy metal wastewater;
D O I:
10.1016/j.jhazmat.2006.06.043
中图分类号:
X [环境科学、安全科学];
学科分类号:
08 ;
0830 ;
摘要:
The article extended the study on the bioaccumulation of cadmium by genetically engineered bacterium Escherichia coli (namely M4) simultaneously expressing a cadmium transport system and metallothionein (NIT). The growth of M4 showed resistance to the presence of cadmium. Compared with Cd2+ uptake capacity by original host bacterial cells, The Cd2+ accumulation of M4 was enhanced more than one-fold. M4 could effectively bind Cd2+ over a range of pH from 4 to 8. The presence of Ni2+ and Mn2+ did not influence Cd2+ uptake remarkably, but Cu2+, Pb2+ and Zn2+ posed serious adverse effects. EDTA could drastically decrease Cd2+ bioaccumulation by M4, whereas the effect of citrate was relatively slight. (c) 2006 Published by Elsevier B.V.