副产物途径的缺失对大肠杆菌合成D-1,2,4-丁三醇的影响
发布时间：2018-11-11 07:28
【摘要】：【目的】敲除副产物途径,提高重组大肠杆菌D-1,2,4-丁三醇(D-1,2,4-Butanetriol,BT)产量。【方法】利用Red重组技术敲除木糖途径xyl AB基因及2-酮-3-脱氧木糖酸代谢途径的yag E及yjh H基因,考察其对重组菌生长、BT生产及副产物积累的影响。【结果】敲除xyl AB基因后,重组菌生物量降低57%,BT产量降低20%,单位菌体产量提高84%,木糖酸积累量提高52%。yag E或yjh H基因单独缺失重组菌生物量分别提高10%和5%,BT产量提高36%和14%。基因共同缺失后重组菌生物量降低了21%,BT产量提高184%,达到2.44 g/L,单位菌体产量提高258%。而共同敲除两途径,生物量降低了72%,虽然单位菌体产量提高了约4倍,但BT产量仅提高43%。p H调控下,重组菌木糖酸积累量下降,BT产量进一步提高,最高达3.11 g/L。【结论】xyl AB基因缺失后,虽有利于提高BT途径的效率,但由于木糖无法进入PPP途径及木糖酸积累,造成生物量降低,不利于BT合成。单独敲除yag E或yjh H后BT产量略有提高,而共同敲除这两基因更为有效地调整碳流向BT合成偏转。两途径共同敲除利于BT的合成,但由于菌体量的减少,无法大量获得BT。
[Abstract]:[objective] to improve the production of recombinant Escherichia coli D-1O2C4- Butanetriol by knockout by-product pathway. [methods] the yag E and yjh H genes of xylose pathway xyl AB gene and 2-keto-3-deoxyxyxyxylic acid metabolic pathway were knocked out by Red recombinant technique. Effects of BT production and by-product accumulation. [results] after knockout of xyl AB gene, the biomass of recombinant bacteria decreased by 57% and BT yield decreased by 20%, and the yield per cell increased by 84%. The biomass of 52%.yag E or yjh H alone deleted recombinant bacteria increased by 10% and 5%, respectively, and the yield of BT increased by 36% and 14%, respectively. After gene deletion, the biomass of recombinant bacteria decreased by 21% and the yield of BT increased by 1844 g / L to 2.44 g / L, and the yield per unit cell increased by 258%. The biomass decreased by 72 times, but the yield of BT was increased only by 43.pH, and the accumulation of xylose acid was decreased, and the yield of BT was further increased. [conclusion] xyl AB gene deletion can improve the efficiency of BT pathway, but because xylose can not enter PPP pathway and xylose acid accumulation, the biomass is decreased, which is not conducive to BT synthesis. The yield of BT increased slightly after knockout of yag E or yjh H alone, and the co-knockout of these two genes was more effective in regulating the deflections of BT synthesis. The knockout of the two pathways is beneficial to the synthesis of BT, but BT. can not be obtained in large quantities because of the decrease of the number of bacteria.
【作者单位】： 江南大学糖化学与生物技术教育部重点实验室;江南大学工业生物技术教育部重点实验室工业微生物研究中心;江南大学化学与材料工程学院;
【基金】：江苏省自然科学基金项目(No.BK20140138) 111项目(No.111-2-06) 江苏省六大人才高峰(No.2014-XCL-017)~~
【分类号】：R378.2
本文编号：2324175
[Abstract]:[objective] to improve the production of recombinant Escherichia coli D-1O2C4- Butanetriol by knockout by-product pathway. [methods] the yag E and yjh H genes of xylose pathway xyl AB gene and 2-keto-3-deoxyxyxyxylic acid metabolic pathway were knocked out by Red recombinant technique. Effects of BT production and by-product accumulation. [results] after knockout of xyl AB gene, the biomass of recombinant bacteria decreased by 57% and BT yield decreased by 20%, and the yield per cell increased by 84%. The biomass of 52%.yag E or yjh H alone deleted recombinant bacteria increased by 10% and 5%, respectively, and the yield of BT increased by 36% and 14%, respectively. After gene deletion, the biomass of recombinant bacteria decreased by 21% and the yield of BT increased by 1844 g / L to 2.44 g / L, and the yield per unit cell increased by 258%. The biomass decreased by 72 times, but the yield of BT was increased only by 43.pH, and the accumulation of xylose acid was decreased, and the yield of BT was further increased. [conclusion] xyl AB gene deletion can improve the efficiency of BT pathway, but because xylose can not enter PPP pathway and xylose acid accumulation, the biomass is decreased, which is not conducive to BT synthesis. The yield of BT increased slightly after knockout of yag E or yjh H alone, and the co-knockout of these two genes was more effective in regulating the deflections of BT synthesis. The knockout of the two pathways is beneficial to the synthesis of BT, but BT. can not be obtained in large quantities because of the decrease of the number of bacteria.
【作者单位】： 江南大学糖化学与生物技术教育部重点实验室;江南大学工业生物技术教育部重点实验室工业微生物研究中心;江南大学化学与材料工程学院;
【基金】：江苏省自然科学基金项目(No.BK20140138) 111项目(No.111-2-06) 江苏省六大人才高峰(No.2014-XCL-017)~~
【分类号】：R378.2
【相似文献】
相关会议论文 前1条
1 赵蕊;朱彤彤;高海军;;生物合成D-1,2,4-丁三醇的代谢工程菌的构建[A];中国化学会第26届学术年会化学生物分会场论文集[C];2008年
相关硕士学位论文 前2条
1 马鹏飞;重组大肠杆菌合成D-1,2,4-丁三醇代谢系统的理性改造[D];北京理工大学;2015年
2 孙文龙;生物法合成D-1,2,4-丁三醇关键基因的克隆及重组菌的构建[D];江南大学;2014年
，本文编号：2324175
本文链接：https://www.wllwen.com/xiyixuelunwen/2324175.html
最近更新
教材专著
