鼠李糖乳杆菌D-乳酸脱氢酶基因ldhD的敲除

发布时间：2017-12-28 02:33

本文关键词：鼠李糖乳杆菌D-乳酸脱氢酶基因ldhD的敲除　出处：《基因组学与应用生物学》2016年06期 　论文类型：期刊论文

【摘要】：聚乳酸由可再生原料L-乳酸合成,是目前应用的最环保的生物塑料之一。鼠李糖乳杆菌JCM1553中的L-乳酸和D-乳酸,它们是由代谢途径中的L-乳酸脱氢酶和D-乳酸脱氢酶分别催化丙酮酸而生成。L-乳酸的光学纯度对于L-乳酸的应用至关重要。因此,为了获取光学纯的L-乳酸,需要敲除该鼠李糖乳杆菌编码D-乳酸脱氢酶的基因ldhD以阻断相关的D-乳酸代谢途径。本研究采用pK18mobsacB自杀质粒运用重叠延伸PCR和同源重组技术成功构建得到重组鼠李糖乳杆菌菌株JCM1553-△ldhD。构建的缺失突变体JCM1553-△ldhD菌株没有引入外源基因,完全符合食品、药品安全要求,发酵液中检测到的L-乳酸含量为99.92%,光学纯度达到99.84%,显著优于野生型菌株。
[Abstract]:Polylactic acid is synthesized by L- lactic acid from renewable raw materials. It is one of the most environmentally friendly bioplastics used at present. L- lactate and D- lactic acid from Lactobacillus rhamnophilus JCM1553 are catalyzed by L- lactate dehydrogenase and D- lactate dehydrogenase, respectively. The optical purity of L- lactic acid is very important for the application of L- lactic acid. Therefore, in order to obtain optically pure L- lactate, we need to knock out the gene ldhD encoding D- lactate dehydrogenase from Lactobacillus rhamnophilus to block the related D- lactic acid metabolic pathway. This study uses the pK18mobsacB plasmid Dutch act by overlap extension PCR and successfully construct the recombinant Lactobacillus rhamnosus strain JCM1553- ldhD homologous recombination technology. The construction of JCM1553- deletion mutant strain ldhD delta without introducing exogenous genes, in full compliance with the food and drug safety requirements, L- lactic acid content in fermentation broth was detected for 99.92%, the optical purity reached 99.84%, significantly higher than the wild type strain.
【作者单位】：广西科学院生物研究所;
【基金】：广西自然科学基金青年基金项目(2013GXNSFBA019113)和面上项目(2015GXNSFAA139087)共同资助
【分类号】：Q78
【正文快照】： 乳酸是传统精细化工产品,广泛被应用于食品、医药、环保和化工加工等领域(D atta and H enry,2006)。乳酸具有旋光性,分为L-型和D-型。L-乳酸合成的聚L-乳酸,具有生物相溶性,能被人体降解代谢,不引起毒害作用;人体若过量摄入D-乳酸有可能导致代谢紊乱而中毒。聚L-乳酸在自然环

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