生物技术通报 ›› 2015, Vol. 31 ›› Issue (3): 121-126.doi: 10.13560/j.cnki.biotech.bull.1985.2015.04.017

• 研究报告 • 上一篇    下一篇

克雷伯氏菌产1,3-丙二醇ldhA基因缺失菌株的构建

陈利飞, 李猛, 马春玲, 杨建楼   

  1. (齐鲁工业大学食品与生物工程学院 山东省微生物工程重点实验室,济南 250353)
  • 收稿日期:2014-08-16 出版日期:2015-03-16 发布日期:2015-03-16
  • 作者简介:陈利飞,男,硕士研究生,研究方向:基因工程,微生物酶技术;E-mail:chenlifei8810@126.com
  • 基金资助:
    济南青年科技明星计划(20090118)

Construction a Metabolic Engineering Strain to Produce 1,3-propanediol from Klebsiella pneumoniae by ldhA Gene Deletion Mutation

Chen Lifei Li Meng Ma Chunling Yang Jianlou   

  1. (Shandong Provincial Key Laboratory of Microbial Engineering,School of Food and Bioengineering,Qilu University of Technology,Jinan 250353)
  • Received:2014-08-16 Published:2015-03-16 Online:2015-03-16

摘要: 克雷伯氏菌(Klebsiella pneumonia)甘油歧化发酵生产1,3-丙二醇(1,3-PD)的过程中,乳酸是氧化途径最主要的副产物,乳酸的产生和积累,不仅限制了菌体本身的生长,而且严重影响了1,3-丙二醇的转化率。利用λRed重组技术对Klebsiella pneumonia中的酶乳酸脱氢酶基因(ldhA)进行改造。在λRed重组系统作用下,将带有300 bp的线性同源片段ldhA1-Cm-ldhA2与基因组DNA的同源重组,经过抗性筛选和PCR鉴定最终获得了ldhA基因缺失菌株K. pneumonia2-1ΔldhA。经过24 h发酵可知,乳酸最大产出浓度由原来的10.16 g/L降为0.49 g/L,1,3-PD由原来的78.83 g/L增长为85.76 g/L,甘油转化率由60.64%增长到65.97%,提高了5.33%。

关键词: 克雷伯氏菌, ldhA基因, λRed同源重组, 1, 3-丙二醇

Abstract: Production of 1, 3-propanediol from glycerol by Klebsiella pneumoniae is restrained by lactate formation. The increase of lactate in the broth can inhibit cell growth and reduce 1, 3-propanediol conversion rate. The lactate dehydrogenase gene(ldhA)of production lactate by Klebsiella pneumoniae was modified by λRed recombination system. One 300 bp homologous recombinant fragment:ldhAl-Cm-ldhA2 was constructed for the gene knockout. After resistance experiments, PCR determination, K. pneumonia2-1ΔldhA with ldhA gene knocked out obtained by λRed recombination. After 24 h fermentation, the maximum yield of lactate was reduced to 0.49 g/L from 10.16 g/L and the maximum threonine yield of 1, 3- propanediol was increased to 85.76 g/L from 78.83 g/L, comparing with that of the original strain K. pneumonia2-1. The conversation rate of glycerol was improved to 65.97% from 60.64%, increasing by 5.33%.

Key words: Klebsiella pneumonia, ldhA, λRed recombination, 1, 3-propanediol