HWAHAK KONGHAK, Vol.29, No.2, 190-198, April, 1991
Silica Gel을 담체로한 효소의 고정화 및 충전층 반응기에서의 반응속도론적 해석
Hydrolytic Enzyme Immobilization by Cross-linked Silica Gel and Their Kinetic Behaviors in Packed Bed Reactor
초록
본 연구에서는 가수분해효소인 trypsin을 가교결합 고분자인 실리카 겔을 담체로 하여 포괄법으로 고정시키고 고정화된 담체를 일정한 크기로 만든 후 충전층반응기에 넣어 DL-BAPNA 기질을 사용해 trypsin에 대한 반응성을 평가하였다. 25-200cm/hr의 유속범위에서 Michaelis 상수와 최대반응속도 Vm’은 고정화시키지 않았을 경우에 비해 Michaelis 상수는 작게 그리고 최대반응속도는 더 크게 나타났으며 Michaelis 상수는 유속에 따라 감소한 반면 최대반응속도는 증가하였다. 실리카 겔의 담체직경이 0.6mm인 고정화효소에 대한 효율인자는 0.9-1로서 내부저항을 무시할 수 있었으며 외부물질전달계수 KS는 8.82×10-4∼1.75×10-3cm/hr이었다. 또한, Michaelis 상수는 trypsin의 고정화밀도에 의해 영향을 받았으며 고정화된 효소의 양이 10mg trypsin/g silica gel일 때 최적전화율을 나타내었다.
This study is for the immobilization of a hydrolytic enzyme, trypsin, within cross-linked silica gels and their kinetic behaviors in a packed bed reactor using a sensible amide substrate, DL-BAPNA. In the range of linear velocity of 25 to 200cm/hr, Michaelis constants(Km’) and maximum reaction rates(Vm’) for immobilized trypsin were less and greater than those for a soluble trypsin, respectively. In comparison with free enzyme, Michaelis constants decreased but maximum reaction rates increased as linear velocity increased. In the case of supported silica-gel with the spherical diameter of 0.6mm, the internal diffusion resistance was negligible because the effectiveness factor was found to be in the range of 0.9-1 and the mass transfer coefficient(Ks) was in the range of 8.82×10-4 to 1.75×10-3cm/sec. In addition, Michaelis con-stant was the function of the amount of immobilized trypsin(immobilization density) and the conversion was found to be maximized at the immobilization density of 10mg trypsin/g silica gel.
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