The biosorption mechanism of Cr （Ⅳ） ions on Synechococcus sp. biosorbent was studied by analyzing the biosorption kinetics as well as speciation change and bond formation during the biosorption process. The kinetic...The biosorption mechanism of Cr （Ⅳ） ions on Synechococcus sp. biosorbent was studied by analyzing the biosorption kinetics as well as speciation change and bond formation during the biosorption process. The kinetics study shows that the adsorption process of Cr （Ⅳ） consists of a very fast stage in the first several minutes, in which more than half of the saturation adsorption is attained, and a slower stage that approximately follows the first order kinetic model, basically Freundlich isotherm models were observed. Comparative studies of FT-LR spectra of K2Cr2O7, free cells of Synechococcus sp., and Cr-bound cells of Synechococcus sp show that the speciation of chromium that binds to the cells ofSynechococcus sp. is Cr （Ⅲ）, instead of Cr （Ⅳ）, and the carboxylic, alcoholic, amido and amino groups may be involved in the binding of Cr （Ⅲ）. Integrative analyses of the surface electric potential, the effect of pH value on adsorption behavior of Cr （Ⅵ）, and the results of FT-IR show that the biosorption of Cr （Ⅵ） follows two subsequent steps, biosorption of Cr2O7 ^2- by electrostatical force at the protonated active sites and reduction of Cr2O7^2- to Cr^3＋ by the reductive groups on the surface of the biosorbents.展开更多
蓝藻Synechococcussp.PCC7942 HCO3-高亲和转运蛋白操纵子基因cmpABCD是其CO2浓缩机制中的调控基因之一.本研究用携带潮霉素B磷酸转移酶基因(hygromyc in B pho transferase,hpt)筛选标记的同源双臂整合载体pUC-HATH转化蓝藻Synechococc...蓝藻Synechococcussp.PCC7942 HCO3-高亲和转运蛋白操纵子基因cmpABCD是其CO2浓缩机制中的调控基因之一.本研究用携带潮霉素B磷酸转移酶基因(hygromyc in B pho transferase,hpt)筛选标记的同源双臂整合载体pUC-HATH转化蓝藻Synechococcussp.PCC7942,以潮霉素B作为筛选试剂筛选出具潮霉素B抗性的转化藻,运用引物PCR方法证实潮霉素B磷酸转移酶基因表达盒通过质粒pUC-HATH的介导已定点插入蓝藻Synechococcussp.PCC7942基因组中,成功地构建了具有潮霉素B抗性的cmpBCD基因插入失活突变藻株.并最终通过比较野生藻Synechococcussp.PCC7942和突变藻Synechococcussp.PCC7942在不同Na2CO3浓度的改良BG-11培养基中生长特性,探讨了HCO3-高亲和转运蛋白操纵子cmpABCD基因失活对藻体生长的影响.展开更多
美国Cyanotech公司从美国Memphis大学获得了生产销售用基因工程制造的杀死蚊子幼虫的蓝藻植物的世界性独占权。该大学的Edward Stevens,Jr.使用编码来自Bacillus thuringiensis var. israelensis(BTi)的杀虫蛋白的基因性状转化蓝藻植物S...美国Cyanotech公司从美国Memphis大学获得了生产销售用基因工程制造的杀死蚊子幼虫的蓝藻植物的世界性独占权。该大学的Edward Stevens,Jr.使用编码来自Bacillus thuringiensis var. israelensis(BTi)的杀虫蛋白的基因性状转化蓝藻植物Synechococcus。BTi是特异地作用于蚊虫及黑色昆虫(等)。蓝藻植物将成为蚊子幼虫的食物源,将包被来自BTi基因的藻类喷洒在池内。展开更多
基金Project(50321402) supported by the National Natural Science Foundation of China
文摘The biosorption mechanism of Cr （Ⅳ） ions on Synechococcus sp. biosorbent was studied by analyzing the biosorption kinetics as well as speciation change and bond formation during the biosorption process. The kinetics study shows that the adsorption process of Cr （Ⅳ） consists of a very fast stage in the first several minutes, in which more than half of the saturation adsorption is attained, and a slower stage that approximately follows the first order kinetic model, basically Freundlich isotherm models were observed. Comparative studies of FT-LR spectra of K2Cr2O7, free cells of Synechococcus sp., and Cr-bound cells of Synechococcus sp show that the speciation of chromium that binds to the cells ofSynechococcus sp. is Cr （Ⅲ）, instead of Cr （Ⅳ）, and the carboxylic, alcoholic, amido and amino groups may be involved in the binding of Cr （Ⅲ）. Integrative analyses of the surface electric potential, the effect of pH value on adsorption behavior of Cr （Ⅵ）, and the results of FT-IR show that the biosorption of Cr （Ⅵ） follows two subsequent steps, biosorption of Cr2O7 ^2- by electrostatical force at the protonated active sites and reduction of Cr2O7^2- to Cr^3＋ by the reductive groups on the surface of the biosorbents.
文摘蓝藻Synechococcussp.PCC7942 HCO3-高亲和转运蛋白操纵子基因cmpABCD是其CO2浓缩机制中的调控基因之一.本研究用携带潮霉素B磷酸转移酶基因(hygromyc in B pho transferase,hpt)筛选标记的同源双臂整合载体pUC-HATH转化蓝藻Synechococcussp.PCC7942,以潮霉素B作为筛选试剂筛选出具潮霉素B抗性的转化藻,运用引物PCR方法证实潮霉素B磷酸转移酶基因表达盒通过质粒pUC-HATH的介导已定点插入蓝藻Synechococcussp.PCC7942基因组中,成功地构建了具有潮霉素B抗性的cmpBCD基因插入失活突变藻株.并最终通过比较野生藻Synechococcussp.PCC7942和突变藻Synechococcussp.PCC7942在不同Na2CO3浓度的改良BG-11培养基中生长特性,探讨了HCO3-高亲和转运蛋白操纵子cmpABCD基因失活对藻体生长的影响.
文摘美国Cyanotech公司从美国Memphis大学获得了生产销售用基因工程制造的杀死蚊子幼虫的蓝藻植物的世界性独占权。该大学的Edward Stevens,Jr.使用编码来自Bacillus thuringiensis var. israelensis(BTi)的杀虫蛋白的基因性状转化蓝藻植物Synechococcus。BTi是特异地作用于蚊虫及黑色昆虫(等)。蓝藻植物将成为蚊子幼虫的食物源,将包被来自BTi基因的藻类喷洒在池内。
