Cadmium removal from aqueous solution by gene-modified Escherichia coli JM109.
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 (MT). 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.
Deng
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College of Life Science, Shenzhen University, Shenzhen 518060, China. dengxu@szu.edu.cn
Yi
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XE
Liu
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D001692:Biological Transport / Q000187:drug effects / Q000235:genetics; D002104:Cadmium / Q000302:isolation & purification* / Q000378:metabolism; D002413:Cations, Divalent / Q000302:isolation & purification / Q000378:metabolism; D002614:Chelating Agents / Q000494:pharmacology; D024881:Drug Resistance, Bacterial / Q000235:genetics; D004492:Edetic Acid / Q000494:pharmacology; D004926:Escherichia coli / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D005818:Genetic Engineering; D006863:Hydrogen-Ion Concentration; D008668:Metallothionein / Q000235:genetics*; D019216:Metals, Heavy / Q000378:metabolism; D012996:Solutions / Q000737:chemistry; D014867:Water / Q000737:chemistry; D014877:Water Pollution, Chemical; D018508:Water Purification / Q000379:methods*
D002413:Cations, Divalent; D002614:Chelating Agents; D019216:Metals, Heavy; D012996:Solutions; C004203:cadmium-binding protein; D002104:Cadmium; D014867:Water; D008668:Metallothionein; D004492:Edetic Acid