提高大肠杆菌脂多糖产量的类脂A合成途径优化  

Optimizing Synthetic Pathways of Lipid A to Improve Lipopolysaccharide Production in Escherichia coli

作　　者：董笑飞 王小元 DONG Xiaofei;WANG Xiaoyuan(State Key Laboratory of Food Science and Resources,Jiangnan University,Wuxi 214122,China;International Joint Laboratory on Food Safety,Jiangnan University,Wuxi 214122,China;Key Laboratory of Industrial Biotechnology,Ministry of Education,Jiangnan University,Wuxi 214122,China)

机构地区：[1]江南大学食品科学与资源挖掘全国重点实验室,江苏无锡214122 [2]江南大学食品安全国际联合实验室,江苏无锡214122 [3]江南大学工业生物技术教育部重点实验室,江苏无锡214122

出　　处：《食品与生物技术学报》2024年第8期58-67,共10页Journal of Food Science and Biotechnology

基　　金：国家“十三五”重点研发计划项目(2017YFC1600102)。

摘　　要：脂多糖(lipopolysaccharide,LPS)是大肠杆菌细胞外膜的主要成分,因其具有免疫原性,在医学上具有广泛的应用前景。脂多糖分子通常由类脂A、核心糖及O抗原三部分组成。分别敲除大肠杆菌MG1655中的rapZ、fabF和ptsO基因,大肠杆菌中脂多糖产量分别提高了25.0%、27.6%和14.6%。通过联合敲除3个基因并构建菌株MWD001,脂多糖产量提高了30.6%,每克MWD001干细胞(dry cell weight,DCW)中脂多糖合成质量也从出发菌株MG1655的7.73 mg提升至10.10 mg。最后在MWD001基因组中类脂A合成关键基因簇lpxD-fabZ-lpxAlpxB前插入阿拉伯糖诱导的启动子PBAD,脂多糖产量进一步提升至12.24 mg。以上结果表明,在大肠杆菌中敲除rapZ、fabF和ptsO基因,并过表达lpxD-fabZ-lpxA-lpxB基因簇,能够显著提高脂多糖的产量。Lipopolysaccharide(LPS),a major component in the outer membrane of Escherichia coli,possesses immunogenic properties and holds significant potential for medical applications.The LPS molecule typically consists of three parts:lipid A,a core oligosaccharide and O-antigen.Individual deletion of rapZ、fabF or ptsO gene in E.coli MG1655 increased LPS production by 25.0%,27.6%or 14.6%,respectively.MWD001 was constructed by simultaneously deleting all the three genes in MG1655,and a 30.6%increase in LPS production was achieved,with LPS yield per gram of dry cell weight(DCW)rising from 7.73 mg in the parental strain MG1655 to 10.10 mg in MWD001.Finally,an arabinose-induced promoter PBAD was inserted upstream of the key gene cluster lpxD-fabZ-lpxA-lpxB in MWD001 genome,further increasing LPS production to 12.24 mg.These findings demonstrate that deletion of rapZ、fabF and ptsO genes,combined with overexpressing of the gene cluster lpxD-fabZ-lpxA-lpxB,significantly improves LPS production in E.coli.

关 键 词：大肠杆菌 脂多糖 类脂A rapZ fabF ptsO 

分 类 号：Q78[生物学—分子生物学]