Production of Cyclodextrin by Bacillus sp. I-5 Cyclodextrin Glucanotransferase

Bacillus sp. I-5 Cyclodextrin Glucanotransferase에 의한 Cyclodextrin의 영향

  • Kim, Soeng-Hyuck (Department of Food Science & Technology and Research Center for New Bio-Materials in Agriculture, Seoul National University) ;
  • Choi, Jong-Soo (Miwon Foods Company, Ltd.) ;
  • Chung, Kap-Taek (Miwon Foods Company, Ltd.) ;
  • Yoo, Young-Soo (Miwon Foods Company, Ltd.) ;
  • Jung, Dong-Sun (Department of Food Science & Technology and Research Center for New Bio-Materials in Agriculture, Seoul National University) ;
  • Park, Kwan-Hwa (Department of Food Science & Technology and Research Center for New Bio-Materials in Agriculture, Seoul National University)
  • 김성혁 (서울대학교 식품공학과.농업생물신소재연구센터) ;
  • 최종수 (미원식품주식회사 기술연구소) ;
  • 정갑택 (미원식품주식회사 기술연구소) ;
  • 유영수 (미원식품주식회사 기술연구소) ;
  • 정동선 (서울대학교 식품공학과.농업생물신소재연구센터) ;
  • 박관화 (서울대학교 식품공학과.농업생물신소재연구센터)
  • Published : 1994.02.01

Abstract

A cyclodextrin glucanotransferase(CGTase)-producing Bacillus sp. I-5 was isolated from soil and the enzyme exhibited the maximum reaction rate at pH 8.0 and $50^{\circ}C$. It was found that CGTase of I-5 produced ${\beta}-$ and ${\gamma}-CD$ mainly but the production ratio of cyclodextrins (CDs) was influenced by the buffer solution. Sodium acetate significantly stimulated the formation of ${\gamma}-CD$, increasing the content by 35%. The production of CDs was influenced by DE value of starch. The results indicated that DE value in the range of $3.5{\sim}6.0$ were most effective for the CD formation. CGTase was immobilized on the reversibly soluble-insoluble carrier, hydroxypropyl mothylcellulose acetate succinate. The immobilized CGTase was soluble at pH 7.5, and precipitated easily at pH 6.0. Enzyme reactor was designed to produce CD continuously. It was composed of three major stages-CD produttion by immobilized CGTase, conversion of the residual dextrin to glucose by amylase and glucoamylase and alcohol fermentation by yeasts to remove the glucose into alcohol. The yield of total CDs was 3.65g from 10g soluble starch.

토양에서 분리한 Bacillus sp. I-5의 cyclodextrin glucanotransferase(CGTase)는 ${\beta}-$${\gamma}-cyclodextrin(CD)$를 주로 생성하는 효소로서 최적 반응조건은 pH 8.0, $50^{\circ}C$에서 최적 반응이었다. 생성되는 CD의 조성비는 buffer 용액에 따라 영향을 받았으며 sodium acetate의 농도를 200mM로 하였을 때 ${\gamma}-CD$의 생성은 35% 가량 증가하였다. 기질인 가용성 전분의 DE value에 따라 CD의 생성이 달라져 $3.5{\sim}6.0$범위의 DE value의 전분을 기질로 사용하였을 때 CD이 가장 많이 생성되었다. CD을 연속적으로 생산하기 위하여 CGTase를 가역적으로 용해-침전되는 담체인 hydroxypropyl methylcellulose acetate succinate에 고정화하였고 고정화된 CGTase는 pH 7.5에서 물에 용해되고 pH 6.0에서 쉽게 침전되는 특성을 나타내었다. CD의 연속적 생산은 고정화된 CGTase에 의한 CD의 생산, 반응하지 않은 기질을 glucose로 분해, glucose를 알코올로 발효시키는 단계로 하는 효소반응기를 개발하여 최종적으로 CD 혼합액과 에탄올이 생성되도록 하였다. 10%의 가용성 전분으로부터 생산된 전체 CD의 양은 3.65g이었다.

Keywords