각종 요인이 물속의 Diastase 활성에 미치는 영향

Effect of External Factors on Diastase Activity in Water

위생공학에서 하수나 공장폐수를 처리할 때 이용하는 생물학적 처리과정은 미생물에서 생성되는 효소에 의하여 이루어 진다. 본 연구에서는 diastase의 활성에 대하여 수소이온 농도, 온도, 기질 농도 및 방해물질 등 여러가지 요인이 미치는 영향을 실험적으로 관찰하여 다음과 같은 결론을 얻었다. (1) diastase의 활성도는 pH $4.0{\sim}7.0$의 범위가 적당하였고 최적치는 pH 5.0이었다. (2) diastase의 활성도는 $30^{\circ}C{\sim}50^{\circ}C$ 높았으며 최적온도는 $40^{\circ}C$였다. (3) 기질농도의 영향을 보면 녹말농도 $750{\mu}g/ml$까지는 diastase의 활성도가 급격히 증가하였고, 그 이후에는 한정속도를 나타냈다. Michaelis 방정식을 적용시켜 보면 한정속도는 $415{\mu}g/ml$ starch removed/ml of reaction mixture/min였고 Michaelis 상수는 $340{\mu}g/ml$였다. (4) 방해물질의 영향을 보면 NaCl 농도 1.0%, $HgCl_2$ 농도 0.001%에서 diastase의 활성은 완전히 억제되었다.

Many factors exert an influence on enzyme activity and thus on the rate of reactions that they catalyse. The most important of these factors are pH, temperature, substrate concentration, and the concentration of some inhibitors present. A solution of the enzyme diastase, which breaks down molecules of the polysaccharide starch to the disaccharide maltose by hydrolysis, was provided. Activity of this enzyme was measured by the rate at which starch was removed from the reaction mixture. These experiments were designed to study this reaction rate under varying conditions and the following results were obtained. 1. The range of optimum pH for this enzyme at room temperature was 4.0-7.0 and the optimum pH was 5.0. 2. The range of optimum temperatures for this enzyme at pH 7.0 was $30^{\circ}C-50^{\circ}C$ and the optimum temperature was $40^{\circ}C$. 3. The relationship between the enzyme activity and substrate concentration could be expressed by the Michaelis-Menten equation. The limiting velocity of this enzyme at room temperature and pH 7.0 was $415{\mu}g$ starch removed/ml of reaction mixture/min and $K_m$, Michaelis constant, was $343{\mu}g/ml$. 4. Inhibitors NaCl and $HgCl_2$ blocked this enzyme activity completely at 1% and 0.01% respectively.