초록
Pleurotus sajor-caju JAFM 1017을 합성배지(合成培地)에 배양(培養)하여 배양중(培養中)에 생성(生成)된 섬유소(纖維素) 분해효소(分解酵素)의 성질(性質)을 검토(檢討)한 결과(結果), 작용최적(作用最適) pH는 avicelase가 pH5.5, CMCase는 pH4.5, ${\beta}-glucosidase$는 pH6.0이었고, pH안정(安定)범위는 avicelase는 $pH5.0{\sim}6.0$, CMCase는 $pH4.0{\sim}6.0$,${\beta}-glucosidase$는 $pH5.5{\sim}6.5$이었다. 최적온도(最適溫度)는 avicelase, CMCase ${\beta}-glucosidase$ 모두 $40^{\circ}C$이었고 열안정성(熱安定性)은 최적온도(最適溫度) 이하(以下)에서 안정성(安定性)을 보였으나 $50^{\circ}C$ 이상(以上)에서는 불안정(不安定)하여 avicelase는 $70^{\circ}C$, 10분(分)에 8.3%정도(程度)의 잔존활성(殘存活性)을 보였다. 효소(酵素)의 활성(活性)은 기질농도(基質濃度)가 증가(增加)함에 따라 증가(增加)하여 avicelase는 1%, CMCase는 0.7%, ${\beta}-glucosidase$ 0.1%까지 비례적(比例的)으로 증가(增加)하였으며 이들의 Km치(値)는 avicelase가 $30.77mg{\cdot}\;avicel/ml$, CMCase는 14.64mg CMC/ml, ${\beta}-glucosidase$는 5.1 3mg salicin/ml이었다. 반응시간(反應時間)에 따른 환원당(還元糖)의 생성(生成)은 Avicelase는 120분(分) CMCase와 ${\beta}-glucosidase$는 60분(分)까지 비례적(比例的)으로 증가(增加)하였다. 금속(金屬) ion의 영향(影響)은 $Ca^{2+}$은 $10^{-2}M$농도(濃度)에서 효소(酵素)의 활성(活性)을 증가(增加)시켰으나 $Hg^{2+},Ag^+$은 크게 저해(沮害)하였다.
Some properties of cellulolytic enzymes produced by Pleurotus sajor-caju JAFM 1017 during its growth in synthetic medium were investigated. The optimum pH of avicelase, CMCase, and ${\beta}-glucosidase$ was pH 5.5, pH 4.5 and pH 6.0, respectively. Avicelase and CMCase were stable within pH 5.0 to 6.0 and 4.0 to 6.0, respectively, and ,${\beta}-glucosidase$ was within pH 5.5 to 6.5. The optimum temperature of avicelase, CMCase and ${\beta}-glucosidase$ was the same of $40^{\circ}C$. The enzymes were stable below the optimum temperature, but the enzymes were unstable over the temperature of $50^{\circ}C$, and avicelase was losing about 91.7% of activity at $70^{\circ}C$ for 10 min. The enzyme activity of avicelase and CMCase was increased in proportion to the substrate concentration within 1% and 0.7%, respectively, and ${\beta}-glucosidase$ was within 0.1%. The Michaelis constants (Km) of avicelase and CMCase were 30.77mg avicel/ml and 14.64m Na-CMC/ml, respectively and ${\beta}-glucosidase$ was 5. 13mg salicin/ml. The reducing sugar production of avicelase was proportionaly increased until 120 min. and CMCase and ${\beta}-glucosidase$ were until 60min. The activity of three cellulolytic enzymes were increased by $Ca^{2+}$ at the concentration of $10^{-2}M$, but were inhibited by $Hg^{2+}$, $Ag^+$.