1株耐Cd细菌的分离、鉴定及其吸附特性研究  

Isolation,Identification and Adsorption Characteristics of a Cd-tolerant Bacterium

作　　者：徐淑霞[1] 杜文涛[1] 王晓雅[1] 张继冉[1] 张世敏[1] 吴坤[1] 

机构地区：[1]河南农业大学生命科学学院/农业部农业微生物酶工程重点实验室,河南郑州450002

出　　处：《河南农业科学》2017年第5期71-76,83,共7页Journal of Henan Agricultural Sciences

基　　金：河南省重点科技攻关项目(152102110054);河南省高等学校重点科研项目(15A180005)

摘　　要：从长期受农药污染的土壤中分离筛选到1株可耐受重金属Cd的菌株,经形态观察、生理生化特性、16S rRNA基因序列和系统发育分析确定该菌株为路德维希肠杆菌(Enterobacter ludwigii),命名为EM1,为Cd污染水体及土壤的修复提供微生物菌株。在无机盐培养基中菌株EM1对Cd^(2+)的最适耐受质量浓度为50 mg/L,吸附Cd^(2+)的最适生长温度为35℃,最适pH值为6.0,在此条件下,其对Cd^(2+)的吸附率最大,为92%。电镜扫描结果表明,在吸附Cd^(2+)的过程中菌体表面分泌大量的胞外多聚物且菌体形态发生变化。红外光谱分析显示,Cd^(2+)胁迫条件下,菌体细胞壁结构并未发生变化,菌株吸附Cd^(2+)的过程主要与菌体表面的羟基、N-H、C-H、多糖中的C-O-C及酰胺基团有关。A Cd-tolerant strain was isolated from the pesticide polluted soil,on the basis of morphological observation,physiological and biochemical characteristics,16 S rRNA gene sequence and phylogenetic analysis,the strain was identified as Enterobacter ludwigii,and named as EM1,so as to provide strain for remediation of Cd polluted water and soil. The optimal Cd^(2+)concentration of strain EM1 against Cd^(2+)was50 mg/L,the optimum growth temperature of strain EM1 against Cd^(2+)was 35 ℃,and the optimum pH value of strain EM1 against Cd^(2+)was about 6. 0. Under this condition,the Cd^(2+)adsorption rate of EM1 was the highest,reached 92%. The SEM results showed that in the process of adsorption of Cd^(2+),the morphology of the strains was changed,and a large number of extracellular polymeric substances were secreted on the strain surface. Infrared scanning analysis showed that under the Cd^(2+)stress condition,the cell walls structure had not changed,and hydroxy,N-H,C-H,C-O-C and aminoacyl were confirmed to be the key functional groups for the strain to adsorb Cd^(2+).

关 键 词：耐镉细菌 路德维希肠杆菌 生物吸附 电镜观察 红外光谱分析 

分 类 号：X172[环境科学与工程—环境科学] X53