Lysine Production by Thialysine Resistant Mutant of Candida utilis ( I ) - Isolation of High Lysine Excreting Mutant of Candida utilis -

Candida utilis의 Thialysine 내성맥리주에 의한 Lysine생산 ( I ) -Candida utilis의 Lysine을 생산하는 Thialysine 내성맥리주의 분리-

  • Bang, Byung-Ho (Department of Agricultural Chemistry, Graduate School, Kyungpook National University) ;
  • Seu, Jung-Hwn (Department of Agricultural Chemistry, Graduate School, Kyungpook National University)
  • Published : 1983.09.01

Abstract

Thialysine significantly inhibited the growth of wild type strain Gondida utilis NCYC-359. In the absence of thialysine, the culture reached stationary phase after 24hr, however, in the presence of 0.5% thialysine, the culture reached stationary phase after 40hr, respectively. Effect of amino acid or vitamin was investigated on recovery of the growth of wild type strain from thialysine inhibition. Glycine, methionine, arginine and tryptophan recovered growth inhibition by thialyslne to some extent. However, vitamins were inert. Especially, lysine at one eighth concentration of thialysine recovered almost fully the growth inhibition. Thialysine resistant mutants were induced from the parent strain of Condida utilis NCYC-359 by NTG treatment. Colonies of thialysine resistant mutants were obtained on agar minimal medium supplemented with 0.1-0.5% thialysine. The frequency of thialysine resistant mutants induced by the first mutation was the highest at 0.1% The wild strain produced no appreciable lysine extracellularly. However, almost thialysine resistant mutants excreted appreciably. Lysine excretion increased after repeated mutation. Finally, of the thialysine resistant mutants induced by NTG, Condida utilis TRN-4006 was obtained. This strain excreted lysine (400$\mu\textrm{g}$/$m\ell$) into the medium with a concomitant decrease of lysine in the intracellular pool.

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