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[1]梁 川,王洁茹 诸葛斌,** 陆信曜,等.基于回补途径的TCA循环改造对克雷伯氏菌生长和甘油代谢的影响*[J].应用与环境生物学报,2019,25(04):1-8.[doi:10.19675/j.cnki.1006-687x.2018.11012]
 LIANG Chuan,WANG Jieru,et al.Effect of TCA cycle modification based on anaplerotic reaction on growth and glycerol metabolism of Klebsiella pneumoniae*[J].Chinese Journal of Applied & Environmental Biology,2019,25(04):1-8.[doi:10.19675/j.cnki.1006-687x.2018.11012]
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基于回补途径的TCA循环改造对克雷伯氏菌生长和甘油代谢的影响*()
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《应用与环境生物学报》[ISSN:1006-687X/CN:51-1482/Q]

卷:
25卷
期数:
2019年04期
页码:
1-8
栏目:
研究论文
出版日期:
2019-07-30

文章信息/Info

Title:
Effect of TCA cycle modification based on anaplerotic reaction on growth and glycerol metabolism of Klebsiella pneumoniae*
文章编号:
201811012
作者:
梁 川1 2 王洁茹2 诸葛斌1 2 ** 陆信曜1 2 宗 红1 2
1江南大学糖化学与生物技术教育部重点实验室 无锡 214122 2江南大学工业生物技术教育部重点实验室,生物工程学院,工业微生物研究中心 无锡 214122
Author(s):
LIANG Chuan1 2 WANG Jieru2 ZHUGE Bin1 2** LU Xinyao 1 2 & ZONG Hong1 2
1 Key Laboratory of Carbohydrate Chemist ry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University , Wuxi 214122, China 2Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Laboratory of Industrial Microorganisms, School of Biotechnology, Jiangnan University , Wuxi 214122, China
关键词:
回补途径磷酸烯醇式丙酮酸羧化酶柠檬酸合成酶TCA循环13-丙二醇
Keywords:
anaplerotic reaction phosphoenolpyruvate carboxylase citrate synthase TCA cycle 13-propanediol
DOI:
10.19675/j.cnki.1006-687x.2018.11012
摘要:
回补途径和TCA循环在克雷伯氏菌(Klebsiella pneumoniae)的中心代谢中扮演着十分重要的角色。本研究拟通过过表达回补途径的关键酶磷酸烯醇式丙酮酸羧化酶(PPC)和柠檬酸(TCA)循环的关键酶柠檬酸合成酶(GLTA)将磷酸烯醇式丙酮酸(PEP)和乙酰辅酶A节点的碳流引入TCA循环,以考察基于回补途径的TCA循环强化对K. pneumoniae生长和甘油代谢的影响。结果显示,单独过表达ppc或gltA基因,TCA循环还原和氧化分支的中间代谢产物琥珀酸和α-酮戊二酸分别增加了8.3倍和1.2倍,甘油利用能力明显增强,除2,3-丁二醇外,其他副产物积累量均有所下降,但1,3-PDO产量分别降低了23.3%、5.9%。共表达ppc和gltA基因后,与对照菌相比,生物量降低了35.7%,甘油利用能力进一步增强,1,3-丙二醇产量提高了10.2%,所有副产物积累量均有所减少;与单独过表达ppc或gltA基因相比,乙醇、乳酸、乙酸积累量未有明显变化,但生物量略有提高,2,3-丁二醇积累量显著降低。上述结果表明,通过共表达磷酸烯醇式丙酮酸羧化酶和柠檬酸合成酶强化TCA循环能够提高菌株的甘油利用能力,弱化副产物合成,强化1,3-丙二醇的合成。
Abstract:
Objectives: The anaplerotic reaction and the tricarboxylic acid (TCA) cycle play important roles in the central metabolism of Klebsiella pneumoniae. Phosphoenolpyruvate carboxylase (PPC) and citrate synthase (GLTA) are key enzymes of anaplerotic reaction and TCA cycle , respectively. The aim of this study was to investigate the effects of strengthening the TCA cycle on cell growth and glycerol metabolism of recombinant K. pneumoniae based on the anaplerotic reaction. Methods: To fufill the objectives, Phosphoenolpyruvate carboxylase encoding by ppc and citrate synthase encoding by gltA were expressed individually or co-expressed in K. pneumoniae.Results: Individually overexpressing ppc and gltA genes led to 8.3-fold and 1.2-fold increase in the production succinate and α- ketoglutarate, respectively. Succinate and α- ketoglutarate are the intermediate metabolites of TCA cycle reductive and oxidative branches. Glycerol utilization ability of recombinants were significantly enhanced . The accumulation of by-products except 2,3-butanediol was decreased, but the yield of 1,3-PDO was decreased by 23.3% and 5.9%, respectively. In comparison with the control strain, co-expression of ppc and gltA resulted in a 35.7% decrease of biomass, but the glycerol utilization ability was further enhanced and 1,3-propanediol titer was increased by 10.2%. In addition, the accumulation of all by-products was decreased. Production of ethanol, lactate, and acetate did not show significant difference with the strains which overexpressed ppc or gltA, but the biomass exhibited increase slightly and the accumulation of 2,3-butanediol was decreased significantly . Conclusions: Enhancing the TCA cycle by co-overexpressing ppc and gltA could improve the glycerol utilization ability of recombinant K. pneumoniae, weak the synthesis of by-products, and enhance the production of 1,3-propanediol.

备注/Memo

备注/Memo:
收稿日期:2018-11-07 接受日期 Accepted: 2019-01-11
*国家轻工技术与工程一流学科自主课题(LITE2018-01)资助?
**通讯作者(E-mail: bzhuge@126.com)
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更新日期/Last Update: 2019-01-24