Studies on the Electrofusion Applied to the Yeast to Produce High Quantity of Organic Germanium

전기융합법을 이용한 게르마늄 강화 효모의 균주개발

  • Oh, Sun-Woo (Research Institute, Geranti Pharm. LTD.) ;
  • Lee, Sung-Hee (Research Institute, Geranti Pharm. LTD.) ;
  • Lee, Hyun-Joo (Department of Nutrition and Culinary Sciences, Hankyong National University) ;
  • Han, Eun-Sook (Department of Food and Nutrition, Chung Ang University)
  • 오선우 (게란티제약(주) 중앙연구소) ;
  • 이성희 (게란티제약(주) 중앙연구소) ;
  • 이현주 (한경대학교 영양조리과학과) ;
  • 한은숙 (중앙대학교 식품영양학과)
  • Published : 2006.10.01

Abstract

Saccharomyces cerevisiae and Zygosaccharomyces rouxii were electrofused and fermented in germaniumfortified nutrients to produce high-yield, organic germanium. The conditions for the preparation of protoplasts from both strains and for electrofusion were studied. The protoplasts of both cells formed long pearl chains and the cell membranes were lysed and fused through cellulase and high frequency voltage $(450{\sim}750V/128{\sim}512\;{\mu}sec)$. The fusants with the fastest growth were selected, and then characterized for their carbohydrate usage and tolerance to glucose and salts. The glucose tolerance of the fusants was better than that of S. cerevisiae and similar to that of Z. rouxii. The fusants appeared to have resistance to 12% NaCl. The cell size of the fusants was greater than that of the parental strains. The fusant cells contained more gemlanium than the parental cells did. The electrofusion of S. cerevisiae and Z. rouxii increased the cell capacity and accumulation of germanium in the yeasts. This method was proved to be effective to produce a high quantity of organic germanium.

고함량 게르마늄을 함유시키기 위해서 Saccharomyces cerevisiae KCTC 7904와 Zygosaccharomyces rauxii KCTC 7966를 전기융합하고 효모 배지에 게르마늄을 첨가하여 게르마늄 강화 효모를 생산하였다. 전기융합된 효모의 원질체는 여러 개의 긴 pearl chain을 형성했고, fusion chamber 내의 강한 직류에 의해서 세포막의 파괴가 일어나고 세포막의 재유착 과정에 의해서 두 세포간의 융합이 일어났다. 융합된 세포를 배지에서 계대하여 성장이 빠른 균체를 선별하고, 탄수화물 이용성 및 당 대성, 염내성의 특성을 확인한 결과, 당내성은 융합체가 Z. rouxii 와 유사하고, S. cereviside보다 좋은 내성을 보였다. S. cerevisiae는 포도당 농도가 40% 이상에서는 생육이 불가능 한 것으로 나타났다. NaCl첨가량에 따른 내성을 살펴본 결과, 융합주는 12%까지 내성을 나타냈다. 융합체의 크기는 친주보다 컸으며, pH 5의 범위에서 게르마늄의 최적 소모율을 나타냈다. pH 5.5에서 건조 효모내 함유되어 있는 게르마늄 농도는 S. cereviside는 1,856 ppm, Z. rouxii는 1,310 ppm, 융합체는 5,180 ppm으로 친주보다 약 4배 이상 게르마늄 농도가 가장 높았다. 게르마늄의 함량을 높이기 위한 S. cereviside와 Z. rouxii의 전기융합은 효모 균체의 체적을 증가시켰을 뿐만 아니라, 게르마늄의 균체내 축적율도 증가시켜서 다량의 유기 게르마늄을 생산하는 데 매우 효과적이었다. 결론적으로, S. cereviside와 Z. rouxii의 전기융합을 통해 개발된 융합체는 40%이상에서 당내성을 보이고, NaCl 15% 이상까지 내성을 나타냈으며, 균체의 크기 및 게르마늄의 흡수율도 친주보다 우수하였고, pH 5에서 최대의 게르마늄 흡수율을 보였다. 이렇게 개발된 융합체는 향후 고함량 게르마늄을 생산하는데 매우 유용한 균주로 이용될 수 있음을 확인하였다.

Keywords

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