Characteristics of the Extracellular Proteolytic Enzyme Produced by Candida lipolytica FM5 Isolated from Mackerel (Scomber japonicus)

Candida lipolytica FM5가 생산하는 균체외 단백분해효소의 특성

Candida lipolytica(C. lipolytica) FM5 was selected as one of the strong saprophytic yeasts isolated from mackerel (Scomber japonicus). The selected strain could produce extracellular proteolytic enzyme. The effective medium for production of proteolytic enzyme by C. lipolytica FM5 was TPPY broth containing Bacto-tryptone $0.5\%$, proteose peptone $0.5\%$, yeast extract $0.25\%$, NaCl $0.5\%$ and $CaCl_2\;0.2\%$. The pattern of proteolytic enzyme production by C. lipolytica FM5 was the almost same as that of growth curve of the strain. Namely, the enzyme production was begun from the early stage of exponential phase and it was reached the highest at the begining of the stationary phase of the yeast growth. The optimum toeperature of the produced proteolytic enzyme was $35^{\circ}C$ and its activity was not significantly changed by pH between 6.5$\~$9.0 and also it was not significantly affected by several kinds of cations such as $Ca^{2+},\;Cu^{2+},\;Fe^{2+}$ and $Mg^{2+}$ but it was affected negatively by some cations such as $Zn^{2+},\;Mn^{2+}$ and $K^+$.

1. C. lipolytica FM5로부터 단백분해 효소를 생산하기 위한 배지로는 Bacto-tryptone $0.5\%$, proteose peptone $0.5\%$, yeast extract $0.25\%$, NaCl $0.5\%$, 그리고 $CaCl_2\;0.2\%$인 TPPY broth가 가장 효과적이었다. 2. 단백분해효소의 생성은 C. lipolytica FM5의 증식과 거의 일치하는 증식관련형으로서 균의 생육이 최대에 도달한 배양 48시간째에 효소의 생성량도 최대치를 나타내었다. 3. 효소반응의 최적온도는 $35^{\circ}C$였으며, pH 6.5$\~$9.0의 범위에서 효소활성은 거의 변화가 없었다. 4. $Ca^{2+},\;Cu^{2+},\;Fe^{2+}\;Mg^{2+}$등의 금속이온은 효소활성에 큰 영향을 미치지 않았으나 $Zn^{2+},\;Mn^{2+}\;K^+$ 등은 효소활성을 다소 저해하였다.