Studies on the $\beta$-Galactosidase from Thermophilic Bacterium - On the Production, Purification of Enzyme and the Properties of the Purified Enzyme -

고온성세균의 $\beta$-Galactosidase에 관한 연구( II )-효소의 생산, 정제 및 정제효소의 성질-

This experiment was carried out to optimize the condition for the enzyme production by selected strain in the basal medium, to purify the enzyme and to characterize the purified enzyme. The results obtained were as follows. 1. The optimal conditions for the $\beta$-galactosidase production were initial pH 7.0 and temperature $65^{\circ}C$. 2. Enzyme was induced by the addition of lactose and galactose, and it was intracellular enzyme. 3. The purified enzyme was obtained with the increased level of activity approximately 28.5 folds as compared with crude enzyme and the yield of 15.2% by means of DEAE-Cellulose column chromatography, Sephadex G-150 gel filtration 4. $\beta$-galactosidase from final step of purification showed a sing1e protein band on polyacrylamide gel disc electrophoresis. 5. The optimal temperature and pH of the purified enzyme were $65^{\circ}C$, pH 6.5 for the hydrolysis of lactose.

전보에서 분리 동정한 Y-33 균주의 $\beta$-galactosise 효소생산조건을 검토하고 효소를 정제하여 정제효소의 성질을 조사한 결과는 다음과 같다. 1. 효소생산을 위한 최적초발 pH는 7.0이었고 최적온도는 $65^{\circ}C$이었다. 2. 효소는 lactose와 galactose에 의하여 유도되어졌으며 세포내효소이었다. 3. 조효소액을 1차 DEAE-cellulose, 2차 DEAE-cellulose column chromatography 및 Sephadex G-150로 gel filtration하여 정제도가 28.3배, 수율이 15.2%의 정제효소를 얻었다. 4. 정제효소는 polyacrylamide gel 전기 영동에 의하여 순도가 검정되었다. 5. 정제효소의 유당가수분해를 위한 최적작용 온도는 $65^{\circ}C$. pH는 6.5이었다.