Production of Glycosyl Sucrose by Cyclodextrin Glycosyltransferase of Alkalophilic Bacillus sp. No.4 and Its Application for Low-Cariogenic Sugar

호알칼리성 Bacillus sp. No.4의 Cyclodextrin Glycosyltransferase에 의한 Glycosyl Sucrose의 생산과 저충치성 당으로서의 응용

Action of a cyclodextrin glycosyltransferase (CGTase) produced from alkalophilic Bacillus sp. No.4 was studied in a solution containing starch and sucrose to prepare glycosyl sucrose syrup with good sweetness and antidecaying properties of teeth. In the initial stage of the reaction the CGTase produced cyclodextrin, however, the cyclodextrin disappeared and glycosyl sucrose was formed with the lapse of reaction time. The best proportion of sucrose to starch for prodution of glycosyl sucrose was about 1 : 1. The optimum pH and temperature of the coupling reaction was pH 6.0 and $60^{\circ}C$, respectively. Main composition of glycosyl sucrose syrup prepared with 20% starch and 20% sucrose was sucrose 18%, glucosyl sucrose ($G_{2}F$) 15.3% and maltosyl sucorse ($G_{3}F$) 11.3%. And glucose, maltose and maltotriose were produced very little. Smaller amounts of acid and insoluble glucan were formed in the syrup by Streptococcus mtans OMZ176 than in the sucrose. Therefore, the prepared glycosyl sucrose sucrose syrup is expected to prevent teeth from decaying.

Strach와 sucrose의 혼합액에 호알칼리성 Bacillus sp. No.4가 생산하는 cyclodextrin glycosyltransferase(CGTase)를 작용시켜 감미가 우수하고 항우식성이 있는 glycosyl sucrose syrup을 만들기 위한 조건을 검토하였다. 설탕과 전분의 혼합액에 CGTase를 작용시키면 반응 초기에는 cyclodextrin을 생성하지만 반응시간의 경과에 따라 점차 cyclodextrin은 소실되고 glycosyl sucrose가 생성되었다. 이 반응은 설탕과 전분의 비율이 1 : 1 부근이 좋았으며, pH6.0, 온도 $60^{\circ}C$가 최적이었다. 20% starch와 20% sucrose의 혼합액으로부터 제조된 glycosyl sucrose syrup의 주성분은 sucrose 18%, glucosyl sucrose($G_{2}F$) 15.3%, maltosyl sucrose($G_{3}F$) 11.3%이었으며 glucose, maltose, maltotriose는 거의 생성되지 않았다. 제조된 syrup은 Sucrose에 비하여 충치균 Streptococcus mutans OMZ 176에 의한 산생성량이 적고 불용성 glucan의 생성량도 적어 충치 예방효과가 기대되었다.