食品与发酵工业2025，Vol.51Issue(22)：1-9,9.DOI:10.13995/j.cnki.11-1802/ts.042436
大肠杆菌K4无抗生素表达系统的构建与果糖软骨素合成途径优化
Construction of an antibiotic-free expression system in Escherichia coli K4 and optimization of fructosylated chondroitin biosynthesis pathway
摘要
Abstract
Fructosylated chondroitin serves as a crucial precursor for the enzymatic synthesis of chondroitin sulfate(CS).However,its current biosynthesis faces significant challenges,such as low synthesis efficiency,complex extraction processes,and reliance on antibi-otics during production,which hinder its large-scale production and application.To overcome these limitations,Escherichia coli K4,a strain capable of naturally synthesizing and transporting fructosylated chondroitin,was employed as the chassis cell.A plasmid expression vector,pMUT2 △Hyp3,was developed,demonstrating genetic stability for up to 9 days without antibiotic pressure.By recombinantly over-expressing the UDP-glucose dehydrogenase gene(ugdA2)from Coryne bacterium glutamicum and the UDP-N-acetylglucosamine pyrophos-phorylase gene(glmU)from Bacillus subtilis,the precursor synthesis pathway was enhanced,increasing fructosylated chondroitin produc-tion in shake-flask cultures to 0.95 g/L.Further optimization of the fermentation medium components elevated the yield to 1.35 g/L.Fi-nally,antibiotic-free fermentation in a 3 L bioreactor achieved a production level of 7.5 g/L within 48 hours,with a yield of 4.4％.This study not only achieved the biosynthesis of fructosylated chondroitin and eliminated antibiotic dependency in recombinant E.coli K4 fer-mentation systems but also laid the groundwork for scalable,environmentally friendly enzymatic production of chondroitin sulfate.关键词
无抗生素表达系统/果糖软骨素/硫酸软骨素/多糖/大肠杆菌K4Key words
antibiotic-free expression system/fructosylated chondroitin/chondroitin sulfate/polysaccharide/Escherichia coli K4引用本文复制引用
孙婕妤,朱雨豪,石智诚,肖森,黄子洋,徐志兵,堵国成,陈坚,康振..大肠杆菌K4无抗生素表达系统的构建与果糖软骨素合成途径优化[J].食品与发酵工业,2025,51(22):1-9,9.基金项目
国家自然科学基金项目(32400056) （32400056）
江苏省合成生物基础研究中心资助(BK20233003) （BK20233003）
无锡市产业创新研究院先导技术预研项目(XD24006) （XD24006）
