香菇纤维素酶和半纤维素酶的热效应

Thermo-Effect on Cellulase and Hemicellulase of Lentinula effaces

本文测定了温度对香菇胞外纤维素酶和半纤维素酶活性的影响。木屑基质培养90天的香菇胞外游纸纤维素酶（C_1酶）、羧甲基纤维素酶（C_X酶）和半纤维素酶（H_C酶）的最适作用温度分别是55℃、55～60℃和50℃。在50～55℃条件下保温1小时后,C_1酶和H_C酶活性大幅度下降,而C_x酶活性下降较为缓慢,具有较高的热稳定性。本文提出相对活力系数（Relative activity coefficient,RAC）作为表示香菇菌丝生长温度与酶最适作用温度之间关系的一个参数。

The effect of temperature on extracellular ctllulasc and hemicellulase was detected. After 90 days cultivation on sawdust medium, it was found that the best suitable temperature of extracellular cellulaso, extracellular carboxymcthyl cellulase and extracellular hemicellulase was 55℃), 55-60℃ and 50℃ respectively. After 1h treatment at 50-55℃, cellulase and hemicellulase activity dropped significantly, but carboxymethyl cellulase activity decreased slowly. The results indicated that carboxymethyl cellulase was more thermostable. It is considered that the relative activity coefficient could be used as index to show the relationship between Lentinula edodes mycelium growth temperature and the best suitable temperature of enzyjne activity.