摘要
以LacDNA片段为探针,筛选了pUCl9为载体构建的乳链球菌(S.1actis)6030菌株的质粒DNA文库,得到插入片段约5.0kb的阳性克隆,并对插入片段进行限制性酶切分析;用ONPG法测定了重组质粒在大肠杆菌细胞中乳糖酶的表达水平。
Lactose metabolism in Streptococcus lactis 6030 was associated with a large plasmid bank. The genes encoding β-galactase from the plasmid of S. lactis 6030 was cloned into the vector pUCl9 in Esherichia coli. The restriction endonuclease map of the 5.0kb PstI insert fragment was analyzed. The recombinant plasmid was expressed in E.coli by IPTG induction,and theβ-galactase production level and activity were determined by the ONPG method.
出处
《食品科学》
EI
CAS
CSCD
北大核心
2003年第2期26-28,共3页
Food Science
