乳酸乳球菌镉抗性菌株的鉴定及质粒消除的研究  

Studies on the Identification and Plasmid Curing of the Lactococcus Lactis Cadmium Resistance Strain

作　　者：范丽平[1] 刘丽波[1] 刘芳[1] 柳国霞[1] 霍贵成[1] 

机构地区：[1]乳品科学教育部重点实验室(东北农业大学)

出　　处：《中国食品学报》2008年第4期147-153,共7页Journal of Chinese Institute Of Food Science and Technology

基　　金：国家“863”计划项目(No.2002AA248041)

摘　　要：为构建乳酸菌食品级载体/受体系统,从分离自内蒙古传统乳制品103株乳源性乳酸菌中筛选出7株高浓度镉抗性菌株。特异性16SrDNA PCR扩增产物的序列测定结果表明,其中两株为乳酸乳球菌。PCR扩增镉抗性基因部分序列证实了这两株乳酸乳球菌含有镉抗性基因,为镉抗性阳性菌株。通过物理和化学方法消除乳酸乳球菌内源质粒,确定了镉抗性质粒,并获得一系列衍生菌株,包括无质粒菌株。为进一步研究各种质粒的功能及基因表达提供了理想的宿主,也为乳酸菌食品级载体/受体系统的构建奠定了基础。Seven cadmium resistance strains were screened from 103 strains in Inner Mongolia traditional dairy product. Results of specific 16SrDNA PCR amplification product sequence analysis revealed that two of them belong to Lactococcus lactis. They were confirmed to have the cadmium resistance determinant by PCR amplification. The cadmium resistance plasmid and the plasmid-free strain was identified following plasmid curing by using chemical curing agents or changing growth condition. Providing host for studying function of plasmid and gene expression, also providing basis for constructing lactic acid bacteria food-grade vector/host system.

关 键 词：乳酸乳球菌 镉抗性 质粒消除 

分 类 号：TS201.3[轻工技术与工程—食品科学]