嗜热芽孢杆菌产耐热蛋白酶稳定性的研究

Stability of a thermostable protease from a thermophilic Bacillus

实验室成功地分离保存了一株产蛋白酶的耐热芽孢杆菌.该菌所产的蛋白酶最适pH 7.5,在pH4.0-9.0时较稳定.最适温度为70℃,80℃以下时热稳定性较好,在稳定的pH或温度下能保持1 h以上活性不变.通过添加Ca^2＋,Li^＋,Co^2＋,Mg^2＋等12种金属离子证实该酶为金属激活蛋白酶,其中Li＋提高该酶活性最显著.氧化剂过氧化氢可以提高该酶的活力,表面活性剂如Tween 80和Triton X-100对酶活力影响不大.该蛋白酶对各种常用的商品洗涤剂耐受能力较强,在洗涤工业中具有较好的应用前景.

A thermophilic Bacillus which can produce a thermostable protease was separated and preserved. The protease had a good stability between pH 4.0-9.0. Its optimum pH was pH 7.5. It was of good stability when below 80℃. The optimum temperature was 70 ℃ ; and its aetivity almost had no change in stable pH or temperature over an hour. The protease proved to be a metalloprotease by adding 12 kinds of metal ions such as Ca^2＋ ,Li^＋ ,Co^2＋ ,Mg^2＋ ; and Li^＋ increased the activity of the protease most. H2O2 could reinforce the activity of the protease; and surfactants such as Tween 80 and Triton X-100 had little influence on it. The protease markedly exhibits its tolerance against a variety of detergents. Therefore it can be used as an excellent additive in industrial applications, especially in the detergent industry.