Abstract
An ATP regeneration system was used for the production of glutathione which was synthesized by a sequential action of ${\gamma}$-glutamyl-cysteine synthetase and glutathione synthetase. The synthetases above were produced in the recombinant E. coli (TG1/pDG7) with the highest specific production yield of 31 mg glutathione/g wet cell. Bakers yeast was considered to have economically a better ATP regeneration system although the glutathione production yield was lower than that of acetate kinase. It was also observed that the ATP regeneration system of bakers yeast was superior to that of Saccharomyces cerevisiae ATCC24858. The yield of glutathione production with bakers yeast was 36% with the ATP concentration of 5 mM. To avoid the cysteine limitation during the early phase of glutatione production, an extra cysteine was added at 2 hours after reaction and the production yield increased 1.91 times. The effectiveness of bakers yeast as an ATP regeneration system was proved by several sets of extra feeding experiments. The product inhibition by glutathione above 14 mM was also observed.
글루타치온 생산에 필요한 ${\gamma}$-glutamylcysteine synthetase와 glutathione synthetase 효소의 활성을 위한 ATP 재생산계에 대하여 연구하였다. 글루타치온 합성용 효소를 생산하는 E. coli TG1/pDR7${\alpha}$의 최적 배양하였으며 이때 글루타치온의 생산농도는31 mg/g wet cell이었다. 빵효모를 이용한 글루타치온의 생산수율은 acetate kinase보다 낮았으나, 경제성의 면에서는 더 우수할 것으로 판단된다. ATP 재생산계로 빵효모가 Saccharomyces cerevrsiae ATCC24858보다 더 우수함을 보였다. ATP농도 5mM에서 cysteine에 대한 글루타치온의 생산 수율은 36%이었다. Cysteine의 소모에 의한 글루타치온 생산 제약을 피하기 위하여 cysteine을 반응 2시간에 추가 공급함으로써 글루타치온 생산수율을 1.91배 증가시켰다. 다양한 기질 추가 실험 결과에 의해 빵효모에 의한 ATP재생산계가 유효하고, 14mM이상의 글루타치온 농도에서는 산물저해 현상이 있는 것으로 나타났다.
