文献类型：期刊文献

中文题名：短链硫酯酶缺失对大肠杆菌合成聚羟基丁酸乳酸酯的影响

英文题名：Effect of short-chain thioesterase deficiency on P(3HB-co-LA) biosynthesis in Escherichia coli

作者：魏香菊[1];吴榉[1];郭鹏业[1];周胜敏[1];吴辉[1]

机构：[1]华东理工大学生物反应器工程国家重点实验室,上海200237

年份：2021

卷号：37

期号：1

起止页码：196

中文期刊名：生物工程学报

外文期刊名：Chinese Journal of Biotechnology

收录：CSTPCD;;Scopus;北大核心:【北大核心2020】；CSCD:【CSCD2021_2022】；PubMed;

基金：国家自然科学基金(No.21776083);国家重点研发计划(No.2017YFB0309302);中央高校基本科研业务费项目(No.22221818014);“111”计划(No.B18022)资助

语种：中文

中文关键词：聚羟基脂肪酸酯;聚羟基丁酸乳酸酯;大肠杆菌;木糖发酵;硫酯酶

外文关键词：polyhydroxyalkanoates;P(3HB-co-LA);Escherichia coli;xylose fermentation;thioesterase

摘要：聚羟基脂肪酸酯(Polyhydroxyalkanoates,PHAs)是一种具有优质生物相容性的可降解生物基材料,其理化性质优越,具备替代石油基塑料的潜力。P(3HB-co-LA)是PHAs的一种,融合了聚乳酸(Polylactic acid,PLA)和聚3-羟基丁酸(poly(3-hydroxybutyrate),P(3HB))共同的优点,具有更好的韧性和透明度。文中首先在大肠杆菌MG1655中通过质粒表达外源基因phaA、phaB、phaCm和pctth,发酵生产出乳酸含量为23.8mol%的P(3HB-co-LA),在此基础上缺失dld基因得到菌株WXJ01-03,其合成的聚合物中乳酸组分含量提升至37.2 mol%。当硫酯酶基因ydiI和yciA基因继续被敲除后,生产的共聚物中乳酸组分进一步提升至42.3 mol%和41.1 mol%。最后将3个基因dld、yciA和ydiI同时缺失得到重组菌株WXJ03-03,并通过该重组菌株获得了乳酸组分含量为46.1 mol%的共聚物。通过比较不同碳源的发酵结果得知,木糖有利于提高共聚物中乳酸组分含量。上述实验结果表明,在木糖发酵中短链硫酯酶基因缺失阻碍了大肠杆菌胞内的LA-CoA被降解,可有效提高聚合物中乳酸组分的摩尔百分比。
Polyhydroxyalkanoates(PHAs)have obtained much attention in biomaterial fields due to their similar physicochemical properties to those of the petroleum-derived plastics.Poly(3-hydroxybutyrate-co-lactate)[P(3HB-co-LA)]is one member of the PHAs family,and has better toughness and transparency compared to existing polylactic acid(PLA)and poly[(R)-3-hydroxybutyrate][P(3HB)].First,we confirmed the one-step biosynthesis of P(LA-co-3HB)with the lactate fraction of 23.8 mol%by introducing P(3HB-co-LA)production module into Escherichia coli MG1655.Then,the lactate fraction was increased to 37.2 mol%in the dld deficient strain WXJ01-03.The genes encoding the thioesterases,ydiI and yciA,were further knocked out,and the lactate fraction in the P(3HB-co-LA)was improved to 42.3 mol%and 41.1 mol%respectively.Strain WXJ03-03 with dld,ydiI and yciA deficient was used for the production of the LA-enriched polymer,and the lactate fraction was improved to 46.1 mol%.Notably,the lactate fraction in P(3HB-co-LA)from xylose was remarkably higher than from glucose,indicating xylose as a potent carbon source for P(3HB-co-LA)production.Therefore,the deficiency of thioesterase may be considered as an effective strategy to improve the lactate fraction in P(3HB-co-LA)in xylose fermentation.