L-Phenylalanine Production by Regulatory Mutants of Excherichia coli K-12

Escherichia coli K-12 대사조절 변이주에 의한 L-페닐알라닌 생산

  • Lee, Sae-Bae (R &D Center, MiWon Co., Ltd.) ;
  • Park, Chung (R &D Center, MiWon Co., Ltd.) ;
  • Won, Chan-Hee (R &D Center, MiWon Co., Ltd.) ;
  • Choi, Duk-Ho (R &D Center, MiWon Co., Ltd.) ;
  • Lim, Bun-San (R &D Center, MiWon Co., Ltd.)
  • 이새배 ((주)미원 연구소) ;
  • 박청 ((주)미원 연구소) ;
  • 원찬희 ((주)미원 연구소) ;
  • 최덕호 ((주)미원 연구소) ;
  • 임번삼 ((주)미원 연구소)
  • Published : 1990.06.01

Abstract

In order to overproduce L-phenylalanine, various kind of regulatory mutants were isolated from parental Escherichia coli K-12. MWEC 83 Producing 7.4g/l of L-phenylalanine has been derived as a tyrosine and tryptophan double auxotrophic mutant. To produce L-phenylalanine without adding L-tyrosine and L-tryptophan, revertant strain MWEC 101 was isolated from MWEC 83. Further various analogues and valine resistant mutants were isolated from MWEC 101. MWEC 101-5 was the most excellent strain that produced 17.9g/l of L-phenylalanine after having been cultivated for 54 hours in 15% glucose medium. It was disclosed that activities of rate-limiting enzymes including chorismate mutase and prephenate dehydratase in MWEC 101-5 were desensitized to 2mM L-phenylalanine in the enzyme reaction mixture and that activities level of 3-deoxy-D-arabino-heptulosonic acid-7-phosphate synthase and prephenate dehydratase were increased more than 20 times over those of the parental strain.

Keywords

L-phenylalanne regulatory mutant;enzyme acitivy