球形红细菌去除和转化铅的机理研究  

Studies on removal and transformation mechanism of lead by Rhodobacter sphaeroides

作　　者：白红娟[1] 张肇铭[1] 贠妮[2] 王玉芬[3] 杨官娥[1] 

机构地区：[1]山西大学生命科学与技术学院,太原030006 [2]中北大学化工与环境学院,太原030051 [3]东北大学环境与土木工程学院,沈阳110004

出　　处：《环境科学学报》2007年第4期608-614,共7页Acta Scientiae Circumstantiae

基　　金：国家科技攻关计划项目(No2001BA540C)~~

摘　　要：通过X-射线衍射光谱分析，球形红细菌（Rhodobacter sphaeroides）H菌株对铅离子的转化产物为硫化铅．H菌株在不同浓度Pb^2＋中培养后，研究了该菌株生长细胞对Ph^2＋去除的动力学和该菌体产生半胱氨酸脱巯基酶活性的变化，用聚丙烯酰胺凝胶电泳法分析了其同工酶谱．结果表明，Pb^2＋浓度为25—150mg·L^-1时，去除速率常数k较大，半衰期T1／2较短，去除率较高；Pb^2＋浓度为75、100和150mg·L^-1时，对H菌株产生半胱氨酸脱巯基酶活力有明显的促进作用，Ph^2＋浓度为200mg·L^-1时，对该酶活力有抑制作用．该菌体细胞及亚细胞组分中铅含量测定结果显示。94％的Ph^2＋分布于细胞壁和细胞质内，仅少量存在于细胞膜上，并结合透射电镜观察和红外光谱分析，证明了该H菌株对船离子去除和转化是在细胞质内进行的．The product which Pb^2 ＋ was transformed into by Rhodobacter sphaeroides H strain proves to be lead sulfides through X-ray diffraction diagram analysis. After H strain was cultivated in medium containing different concentrations of Pb^2 ＋ , the removal kinetics by H stain growth cells and the change of activity of cysteine desulthydrase of H strain producing were studied, and the pattern of isoenzymes of the kind of enzyme was further analyzed using PAGE methods. The results demonstrated that the removal rate constants （k） were high, half lives （ T1/2 ） were short and the removal efflciencies were great in the presence of 25 - 150 mg· L^- 1 of Pb^2 ＋ . The activities of cysteine desulthydrase of H strain producing were obviously stimulated in the presence of 75,100 and 150 mg· L^ - 1 of Pb^2 ＋ , respectively, whereas the activity of the kind of enzyme was inhibited in the presence of 200 mg· L ^-1 of Pb^2 ＋ . The measure of cellular subfractions showed that cell wall and cytoplasm fraction concenirated 94% of the lead taken up by cells, but cell membrane only concentrated a fewof the lead. The analysis of TEM and IR spectrum indicated that the removal and transformation of Pb^2 ＋ by H strain were completed inside cytoplasm.

关 键 词：球形红细菌 铅 转化机理 半胱氨酸脱巯基酶 

分 类 号：X172[环境科学与工程—环境科学]