Welcome to Chinese Agricultural Science Bulletin,

Chinese Agricultural Science Bulletin ›› 2021, Vol. 37 ›› Issue (23): 29-37.doi: 10.11924/j.issn.1000-6850.casb2020-0837

Special Issue: 生物技术

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Lactic Dehydrogenase Gene Deletion Mutant of Enterobacter cloacae: Construction and Biological Characteristics

Shi Huiling1,2(), Zhou Yuhang1,2, He Ping1,2, Huang Mengmeng1,2, Shao Shuai1,2, Ge Jingping1,2, Ling Hongzhi1,2()   

  1. 1key Laboratory of Microbiology of Heilongjiang Province, Life Science College, Heilongjiang University, Harbin 150080
    2Agricultural Microorganisms Technology Education Engineering Research Center, Harbin 150500
  • Received:2020-12-28 Revised:2021-04-13 Online:2021-08-15 Published:2021-08-26
  • Contact: Ling Hongzhi E-mail:shl3589@126.com;linghongzhi@163.com

Abstract:

The aims are to construct a lactic dehydrogenase mutant of Enterobacter cloacae by suicide plasmid recombination technique, and lay a foundation for further increasing acetoin yield and expanding the range of strain selection. The homologous fragment was inserted into the suicide plasmid pKR6K by double restriction endonuclease digestion, and the ldh gene knockout plasmid was constructed. Then the ldh gene of E.cloacae was knocked out by bacterial conjugation. Two homologous sequences of E.cloacae lactate dehydrogenase gene were successfully cloned with a length of 526 bp. Sequence alignment analysis showed that the sequence similarity of E.cloacae lactate dehydrogenase gene was 100%. By knocking out the lactate dehydrogenase gene of E.cloacae, a ldh deletion recombinant strain E.cloacaeldh, was successfully constructed, while 2,3-butanediol and acetic acid were increased by 6.8% and 24.3%, respectively. The E.cloacae lactic dehydrogenase deletion engineering strain was successfully created, which lays a foundation for the industrial production of acetoin by the microbial method.

Key words: Enterobacter cloacae, lactate dehydrogenase, suicide plasmid, homologous recombination, gene knockout

CLC Number: