副干酪乳酪杆菌ZY-1内源性质粒分析及其表达系统的构建与应用  

Analysis of endogenous plasmids in Lacticaseibacillus paracasei ZY-1 and development of expression vectors

作　　者：肖路遥 石婷婷 王苏滢 赵庆尧 李伟[1] XIAO Luyao;SHI Tingting;WANG Suying;ZHAO Qingyao;LI Wei(College of Food Science and Technology,Nanjing Agricultural University,Nanjing 210095,Jiangsu,China)

机构地区：[1]南京农业大学食品科技学院,江苏南京210095

出　　处：《生物工程学报》2023年第3期1217-1231,共15页Chinese Journal of Biotechnology

基　　金：国家自然科学基金(31871771,U1903108);江苏省自然科学基金(BK20201320)。

摘　　要：高效稳定的乳杆菌表达载体的构建是实现其菌种改良和个性化菌株开发的关键。本研究从副干酪乳酪杆菌(Lacticaseibacillus paracasei) ZY-1中分离出4个内源性质粒并进行功能分析。通过将pLPZ3与pLPZ4的复制子rep,与pNZ5319质粒的氯霉素乙酰转移酶报告基因cat、pUC19的复制子ori构建大肠杆菌-乳酸菌穿梭载体pLPZ3N与pLPZ4N,进一步加上启动子Pldh3和mCherry红色荧光蛋白,获得表达载体pLPZ3E与pLPZ4E。pLPZ3与pLPZ4质粒大小分别为6 289 bp和5 087 bp,GC含量分别为40.94%和39.51%。2个穿梭载体可成功转化至乳酪杆菌属中,pLPZ4N的转化效率(5.23×10^(2)-8.93×10^(2)CFU/μg)略高于pLPZ3N。乳酸菌表达载体pLPZ3E与pLPZ4E转化至副干酪乳酪杆菌S-NB后,成功获得了mCherry红色荧光蛋白的表达。以P_(ldh3)为启动子构建的重组表达载体pLPZ4E-lacG转化得到的重组菌,其β-半乳糖苷酶酶活性高于野生型菌株。本研究成功构建了大肠杆菌-乳酪杆菌穿梭载体和表达载体,为乳酪杆菌基因工程菌株的研发提供了新的工具。The construction of efficient and stable Lactobacillus expression vector is critical for strain improvement and development of customized strains. In this study, four endogenous plasmids were isolated from Lacticaseibacillus paracasei ZY-1 and subjected to functional analysis. The Escherichia coli-Lactobacillus shuttle vectors pLPZ3N and pLPZ4N were constructed by combining the replicon rep from pLPZ3 or pLPZ4, the chloramphenicol acetyltransferase gene cat from pNZ5319 and the replicon ori from pUC19. Moreover, the expression vectors pLPZ3E and pLPZ4E with the promoter P_(ldh3) of lactic acid dehydrogenase and the mCherry red fluorescent protein as a reporter gene were obtained. The size of pLPZ3 and pLPZ4 were 6 289 bp and 5 087 bp, respectively, and its GC content, 40.94% and 39.51%,were similar. Both shuttle vectors were successfully transformed into Lacticaseibacillus, and the transformation efficiency of pLPZ4N(5.23×10^(2)-8.93×10^(2) CFU/μg) was slightly higher than that of pLPZ3N. Furthermore, the mCherry fluorescent protein was successfully expressed after transforming the expression plasmids pLPZ3E and pLPZ4E into L. paracasei S-NB. The β-galactosidase activity of the recombinant strain obtained from the plasmid pLPZ4E-lacG constructed with P_(ldh3) as promoter was higher than that of the wild-type strain. The construction of shuttle vectors and expression vectors provide novel molecular tools for the genetic engineering of Lacticaseibacillus strains.

关 键 词：副干酪乳酪杆菌 内源性质粒 穿梭载体 表达载体 

分 类 号：Q78[生物学—分子生物学]