[Objective] The purpose of this project was to study cellulase properties of a cellulose decomposing fungus SJ - 1 isolated from cotton stalk decomposing products were studied. [Method] Effects of temperature, pH value and metal ions on cellulase activity were studied, and Michaelis constant Km of enzymatic reaction and the maximum reaction rate Vmax were examined by Lineweaver - Burk method. [ Result]The best reaction temperature to CMCase and FPase was ranged from 50 to 60℃, and the best pH value was 7. 0, which showed the tolerance to high temperature and alkali. K+ and Fe2+ activated the cellulase activity significantly, while Cu2 + , Mg2 + , Ca2+ and Al3 + showed certain inhibition, the inhibition of Al3+ exhibited much more strongly, Cu2+ inhibited FPase strongly as well, Mn2+ showed activation to FPase but inhibition to CMCase, Zn2 + had no influence on cellulase activity. When CMC - Na was taken as substrate, Km and Vmax of the enzymatic reaction were 2.69 mg/mL and 0.53 mg/( mL·min) respectively. [Conclusion] The strain showed good properties of cellulase activity, and provided references for further breeding and alteration of this fungus.%[目的]对从棉秆腐解物中筛选得到的高效棉秆分解真菌SJ-1进行纤维素酶酶学性质的研究.[方法]研究温度、pH、金属离子对纤维素酶活力的影响,并以Lineweaver -Burk作图法测定酶促反应米氏常数Km及最大反应速率Vmax.[结果]该菌株CMCase和FPase的最适反应温度在50～60℃,最适pH为7.0,有较好的耐高温及耐碱能力.K+、Fe2对酶活有显著的激活作用,而Cu2+、Mg2+、Ca2+、Al3+等有一定的抑制作用,其中Al3的抑制作用较为强烈,Cu2+对FPase抑制较强,Mn2-对FPase有激活作用而对CMCase有抑制作用,Zn2对酶活性无明显影响.以CMC - Na做底物时酶反应的Km为2.69 mg/mL,Vmax为0.53 mg/( mL·min).[结论]菌株SJ-1的纤维素酶性质较为优良,为进一步进行菌株的选育与改造提供参考依据.
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