一株耐铅菌株NY-3的分离鉴定及其吸附特性研究

Isolation, Identification and Biosorption Characteristics of a Lead Resistant Strain NY-3

目的:以天津滨海近岸沉积物为材料,进行耐铅优势菌株的分离鉴定,探讨影响菌株铅吸附的因素。方法:通过生理生化特征、16S rDNA序列相似性分析对菌株进行初步鉴定,考察pH值、吸附剂投加量、Pb^(2+)的初始浓度、吸附时间等不同条件下菌株对Pb^(2+)的吸附效果。结果:分离出一株耐铅菌株NY-3,鉴定为Oceanimonas sp.,菌株最大耐Pb^(2+)浓度为300 mg/L。在pH值为6、菌体投加量1 g/L、Pb^(2+)初始浓度为100 mg/L时,吸附时间为60 min,菌株对Pb^(2+)的吸附率达94.16%。NY-3对Pb^(2+)的吸附过程符合Langmuir等温模型(R^2=0.9978),动力学数据拟合准二级动力学模型(R^2=0.9997)。结论:菌株NY-3对铅具有较好的吸附效果,可用于重金属污染的微生物修复。

Objective:The lead resistant bacterium was isolated and identified from the sediments of Tianjin coastal area,and the factors influencing lead adsorption were discussed.Methods:The strain was preliminarily identified by physiological and biochemical tests and by phylogenetic analysis of the homoeologous16S rDNA gene sequences.The effects of Pb^2+adsorption by this strain under different conditions such as pH value,adsorbent dosage,initial concentration of Pb^2+,adsorption time were investigated.Results:A lead resistant strain NY-3was isolated and identified as Oceanimonas sp.,and the maximum tolerant Pb^2+concentration of the strain was300mg/L.Optimum conditions for maximum biosportion were found at pH of6.0with inoculation quantity of1g/L,initial Pb^2+concentration of100mg/L,and contact time of60min at25℃.Under such conditions,the adsorption rate reached94.16%.The Pb^2+adsorption data of NY-3was fitted well on Langmuir isothermal model(R^2=0.9978)and pseudo-second order kinetics model(R^2=0.9997).Conclusion:The isolated strain NY-3had significant tolerance to lead,and it could be used for microbial remediation of heavy metal pollution.