基因工程菌E.coli BL21-NiCoT吸附镍的性能研究

以表达Staphylococcus aureus ATCC6538镍钴转运酶NiCoT基因的基因工程菌E.coli BL21-NiCoT作为生物吸附剂处理含镍废水.结果表明:基因工程菌在pH为4～9时有比较好的吸附效果,30 min就达到了吸附平衡;基因工程菌对Ni2 的富集容量比原始宿主菌有很大的提高,最大平衡富集量从3.76 mg/g增加到11.33 mg/g,增幅达3倍多,溶液中Ni2 的最大去除率也从原来的35.62%增加到91.23%;Cu2 、Cr6 、Zn2 等的存在对吸附没有很大的影响.镍进入细胞内后与羟基和酰胺基团发生结合,蛋白类物质和含羟基类物质在细胞内富集镍的过程中起到重要作用;基因工程菌转接10、20、30、40、50次,重组质粒保持良好的结构稳定性,基因工程菌对镍的富集能力也具有较好的稳定性.

Study on the performance of genetic engineer strain E.coli BL21-NiCoT on nickel biosorption

The nickel-containing wastewater was treated by the genetic engineered strain E. coli BL21-NiCoT, which heterogeneously expressed the NiCoT gene of Staphylococcus aureus ATCC6538. The genetic engineered E. coli BL21-NiCoT had effective biosorption capability in range of pH value from 4 to 9, and achieved biosorption equilibrium in 30 min. The quantity of equilibrium accumulation of the genetic engineered E.coli BL21-NiCoT was 11.33 mg/g, which was 3 times more than the original E. coli BL21. The removal rate of nickel was improved distinctively from 35.62% to 91.23%, too. The existence of Cu 2+,Cr 6+,Zn 2+ ions had little influence on nickel biosorption. The hydroxyl and amido groups bind the nickel ion in the cell. Proteins and substance containing hydroxyl play an important role in the nickel accumulation at the inner cell. The structure of the recombined plasmid was stable and the genetic engineered strain had continuous effective biosorption capability after the strain had been transferred inoculation for 10, 20, 30, 40, 50 times.