中文摘要：

以酶学分析方法研究了不同温度、pH及擞食后不同时间扁额原细首纽虫蛋白酶活性的变化。结果表明，扁额原细首纽虫蛋白酶活力在pH为3和10时出现2个峰值，酸性条件下其蛋白酶的活性明显高于碱性条件。在20～80℃温度范围内，纽虫酸性和碱性蛋白酶活性表现出2种不同的变化趋势。酸性蛋白酶活力在50℃达到最大值；而碱性蛋白酶活力在40℃达到最大值，50℃酶活性急剧下降，对高温比较敏感。扁额原细首纽虫在擞食后，酶活力有明显变化，酸性蛋白酶在擞食后2h达到最大值，之后下降，擞食后8h达到最低水平，之后又有所回升。而碱性蛋白酶活性在搬食后8h达到最大值，16h后维持在较低水平。

英文摘要：

The effects of temperature, pH and feeding on the protease activity of Procephalothrix simulus were studied. The results showed that the peaks of protease activities appeared at pH values of 3 and 10, and the activity of acid protease was higher than that of alkaline protease. The effect of temperature （20～80℃） on acid protease activity was different from that on alkaline protease. Acid protease activity reached the peak value at 50℃; while for the alkaline protease, the optimal temperature was 40℃, and the activity decreased rapidly when the temperature was elevated to 50℃, which indicated that the alkaline protease was sensitive to high temperature. The results also showed that the protease activity of P. simulus varied significantly after feeding. After being elevated to its maximum value 2 h after feeding, the activity of acid protease declined and reached the lowest value at 8 h, then the activity increased again and became stabilized 24 h after feeding. Al-kaline protease, however, increased to the peak value at 8 h, and remained at low levels 16 h after feeding.