Continuous Production of Isomaltooligosaccharides by Immobilized Transglucosidase in a Packed-bed Reactor

충진형반응기에서 고정화 Transglucosidase를 이용한 이소말토올리고당의 연속생산

A packed-bed reactor with immobilized transglucosidase (TG) was operated to test the possibility of continuous production of isomaltooligosaccharides (IMO) and the effect of concentration and feed rate of substrate solution on the production pattern as well as operational stability The pattern of formation of IMO was the same to the one of soluble TG. The concentrations of glucose and isomaltose produced by the packed-bed reactor were gradually decreased as the flow rates were increased regardless of the concentrations and kinds of maltose solution as substrate. Isomaltotriose showed the same tendency except 10% maltose solution. But the concentration of panose was increased and then decreased as the flow rates were increased. The maximum yield of IMO was 52.1% when 10% (w/v) solution was fed to the reactor at 2 mL./min feed rate. When each 20% and 30% (w/v) solution was respectively used at $0.5{\sim}1.0\;mL/min$, the maximum yield were $39.0{\sim}38.0%\;and\;12.1{\sim}14.2%$. The maximum yield was 36.3% at $0.5{\sim}1.0\;mL/min$ when a commercial maltose product containing 20% maltose was used. The reactor was stably operated at $55^{\circ}C$. 85% and 65% of initial activity was maintained for 144 hours and 288 hours of operation, respectively. A reactor analysis strongly an immobilized TG system could apply to continuous production of IMO.

고정화 transglucosidase (TG)를 이용한 충진형 반응기를 만들어 isomaltooligosaccharides (IMO)의 연속생산 가능성을 살펴보고 기질용액의 농도와 유속에 따른 반응산물의 생성패턴과 운전안정성을 조사하였다. 고정화 TG에 의한 IMO의 생성패턴은 soluble TG의 경우와 동일하였다. 충진형반응기에 의해 생성된 포도당과 isomaltose의 농도는 기질인 maltose 용액의 농도와 종류에 관계없이 유속의 증가에 따라 지속적으로 감소되는 경향을 보였고 isomaltotriose 역시 10% 기질용액을 사용한 경우를 제외하고 같은 경향을 보였다. 반면, panose의 농도는 유속의 증가에 따라 증가하다가 감소하는 경향을 보였다. 기질농도가 10% 일 때, IMO의 최대수율은 2 mL/min 유속에서 52.1%였고, 20%와 30% (w/v)일 때는, $0.5{\sim}1.0\;mL/min$ 유속에서 각각 $39.0{\sim}38.0%,\;12.1{\sim}14.2%$의 최대수율을 보였다. 20%의 maltose를 함유한 조제당화액을 사용했을 때의 수율은 유속이 0.5 mL/min일 때 36.3%였다 본 충진형반응기는 $55^{\circ}C$에서 안정되게 운전되었다. 144시간 운전후에 초기 활성의 85%, 288시간 경과후에도 약 65%의 활성이 잔존하였다. 본 실험결과로 보아 IMO를 생산하기 위해 고정화 TG를 이용한 충진형반응기를 적용하는 것은 가능성이 클 것으로 예상되었다.