耐高温中性蛋白酶产生菌株kn1的部分酶学性质及发酵-中国农学通报.pdf

中国农学通报 2011,27(30): 177-181 Chinese Agricultural Science Bulletin 耐高温中性蛋白酶产生菌株KN1 的部分酶学性质 及发酵条件的研究 张 蕾，孙 萌，刘 岳，张海予 （北京农学院食品科学学院，北京102206） 摘 要：为了给酶的应用提供理论依据，采用Folin-酚法测定蛋白酶活性，通过单一变量控制对KN 1 菌株 的蛋白酶酶学特性和发酵条件进行研究。该酶的最适作用温度为75℃，最适作用pH 7.5 ，Cu2+ 对酶活有 促进作用；EDTA 对酶活有明显的抑制作用，而PMSF 对酶活的抑制作用小，推测KN 1 菌株产生的是一 种金属蛋白酶；经SDS 处理后KN 1 的蛋白酶仍能保持较高的活性。KN 1 菌株的蛋白酶的最佳发酵条件 为37℃培养4 天，最佳碳源为玉米粉，最佳氮源为豆饼粉。KN 1 菌株的蛋白酶是一种耐高温中性蛋白 酶，最适作用温度达到75℃，在最适合条件下，酶活性可达1498.84 U/mL ，具有良好的应用前景。 关键词：耐热中性蛋白酶；蛋白酶活性；酶学性质；发酵条件 中图分类号：S182 文献标志码：A 论文编号：2011-1337 Research on Enzyme Characteristics and Fermentation Conditions of the Thermophilic Neutral Protease-Producing Strain KN1 Zhang Lei, Sun Meng, Liu Yue, Zhang Haiyu (Beijing University of Agriculture, Beijing 102206) Abstract: In order to provide theoretical basis for application of the thermophilic neutral protease, the Folin-phenol method had been used to detect the activity of the protease. The enzyme characteristics and the fermentation conditions were determined by the single factor control experiment. This enzymes optimal acting temperature and pH value were 75℃ and 7.5 respectively. Cu2 + could activate the enzyme. EDTA has the obvious inhibition on the enzyme, but PMSF had a little inhibition on the enzyme. The protease was postulated to a metal protease. After treating with SDS, the protease of KN 1 remained high activity. The KN 1 strains best fermentation conditions were cultured under 37℃for 4 days, the best carbon resource was the corn-starch and the best nitrogen resource was bean powder. The protease produced by KN 1 strain was a kind of thermophilic