Two phase system was examined on the possibility applicable to the enzymatic fat splitting process so as to broaden the substrate range up to solid fats and to enhance the productivity. Organic solvent utilized in two phase system was necessarily water-immiscible so that the enzyme might not be inactivated by hydrophobic denaturation.
The lipase activity was maximum in two phase system comprised iso-octane at 35℃ and pH 6.0, and the activation energy of the lipase was 10.1 Kcal/mole.
The lipase activity was examined for tripalmitin of the model as solid fat. The result indicated that the lipase activities in two phase system was 2-3 times higher than in water system, and the discrepancy of the lipase activity between two systems was increased. Apparent Vm and Km of the soluble lipase in two phase system were 16.7 umole/ml/hr and 25 mmole on tripalmitin, respectively.
The effect of carrier types of immobilized lipase was examined in two phase system. While the optimum pH of hydrophilic gel entrapped lipase (ENT-4000) was pH 7.0, the reaction rate of the hydrophobic gel entrapped lipase was less dependent to pH variations. In latter case, stability was slightly enhanced at pH 7.
As a degree of hydrophobicity of the immobilized matrix was increased, $Vm_{(app)}$ was increased for 2.17 to 3.35 umole/ml/hr, but $Km_{(app)}$was approximately constant in the range of 17.6-18.8% $＼frac{v}/{v}$. Thus, the reaction rate of the immobilized lipase was increased as the degree of hydrophobicity of the immobilized matrix was increased. i.e. polarity of microenvironment of lipase was decreased.
효소적으로 fats 과 oils 을 가수분해 할 때 유기용매를 사용하여 생산성의 증가와 고체지방까지 기질 범위를 넓히는 실험을 하였다.
유기용매는 물에 불용성인 유기용매를 사용하여 효소를 소수성 파괴에 대해 안정하게 하였다. 여러 유기용매 가운데 지방의 가수분해 효율이 가장 좋은 유기용매는 iso-octane 이었다. Iso-octane으로 이루어진 two phase system은 pH 6.0 과 온도 35℃ 에서 가장 높은 효소 역가를 보였다. 이때의 활성화 에너지는 10.1 Kcal/mole 이었다.
고체 지방의 표본으로 사용한 tripalmitin 에 대한 리파 - 제의 역가는 물에서 반응시켰을 때에 비해 two phase system 에서 2 - 3 배 이상 증가하였다. 그 차이는 기질 농도가 높아질수록 커진다.
고정화 담체의 성질이 효소에 미치는 영향을 two phase system 에서 조사하였다. 친수성 담체의 경우 (ENT-4000) 최적 pH 는 7.0인 반면에 소수성 담체의 경우 (ENTP-2000) pH에 따른 반응속도는 크게 변하지 않고 단지 7 일 때 안정도가 조금 더 좋은 것으로 나타났다.
담체의 소수성을 변화시킬 때 리파 - 제의 $Vm_{(app)}$ 는 2.17 에서 3.35 umole/ml/hr로 크게 증가하였지만 $Km_{(app)}$ 은 18.8 에서 17.6% 로 그다지 크게 감소하지는 않았다. 따라서 담체가 소수성이 될수록 반응속도는 빨라진다는 것을 알았다.
