| Summary: | 碩士 === 元智大學 === 生物科技與工程研究所 === 98 === Heavy metals are common contaminants found in polluted area. We have identified a gene (heavy metal translocating P-type ATPase; hmtp) that might be involved in heavy metal resistant traits of Enterobacter sp. CD01(a heavy metal resistant strain isolated from heavy metal contaminated soil) in a previous study via fosmid library and in vitro transposon mutagenesis. The complete gene was then identified, cloned and expressed in a suitable Escherichia coli using pGEM-T as the vector. E. coli W3110, RW3110 (zntA::Km), GG48 (DzitB::Cm zntA::Km) and GG51 (DzitB::Cm] were used to study the possible effects of this gene to heavy metal resistance, cadmium and zinc in particular. Among these E. coli strains, RW3110 and GG48 showed more sensitive to cadmium and zinc compared to the wildtype E. coli W3110 and strain GG5, therefore were chosen for the reference hosts for further evaluation of the gene’s effect. The results showed that this heavy metal translocating P-type ATPase gene could increase the ability for zinc and cadmium resistance in the tested microorganisms. In addition to study on the genes involved in heavy metal resistance, we also examined the cadmium adsorption by Enterobacter sp. CD01 and another isolate (Stenotrophomonas sp. CD02). Moreover, the exopolysaccharide production and Transmission electron microscope of Stenotrophomonas sp. CD02 grown in medium containing cadmium were also examined in this study.
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