Badoei-Dalfard Arastoo, Karami Zahra, Ravan Hadi
a Department of Biology, Faculty of Sciences , Shahid Bahonar University of Kerman , Kerman , Iran.
Prep Biochem Biotechnol. 2015;45(2):128-43. doi: 10.1080/10826068.2014.907176.
Bacillus sp. JER02 is a bacterial strain that can be grown in a medium containing organic solvents and produce a protease enzyme. JER02 protease was purified with a yield of 31.9% of total protein and 328.83-fold purification. Km and Vmax of this protease were established as 0.826 µM and 7.18 µmol/min, respectively. JER02 protease stability was stimulated about 80% by cyclohexane. It exhibited optimum temperature activity at 70°C. Furthermore, this enzyme was active in a wide range of pH (4-12) and showed maximum activity at pH 9.0. The nonionic detergents Tween-20 and Triton X-100 improved the protease activity by 30 and 20%, respectively. In addition, this enzyme was shown to be very stable in the presence of strong anionic surfactants and oxidizing agents, since it retained 77%, 93%, and 98% of its initial activity, after 1 hr of incubation at room temperature with sodium dodecyl sulfate (SDS), sodium perborate (1%, v/v) and H2O2 (1%, v/v), respectively. Overall, the unique properties of the Bacillus sp. JER02 protease suggested that this thermo- and detergent-stable, solvent-tolerant protease has great potential for industrial applications.
芽孢杆菌属JER02是一种能在含有有机溶剂的培养基中生长并产生蛋白酶的细菌菌株。JER02蛋白酶经纯化后，其产量占总蛋白的31.9%，纯化倍数为328.83倍。该蛋白酶的米氏常数（Km）和最大反应速度（Vmax）分别确定为0.826 μM和7.18 μmol/min。环己烷可使JER02蛋白酶的稳定性提高约80%。它在70°C时表现出最佳温度活性。此外，这种酶在较宽的pH范围（4 - 12）内都有活性，在pH 9.0时表现出最大活性。非离子洗涤剂吐温20和曲拉通X - 100分别使蛋白酶活性提高了30%和20%。此外，该酶在强阴离子表面活性剂和氧化剂存在下表现出非常稳定，因为在室温下分别与十二烷基硫酸钠（SDS）、过硼酸钠（1%，v/v）和过氧化氢（1%，v/v）孵育1小时后，它分别保留了其初始活性的77%、93%和98%。总体而言，芽孢杆菌属JER02蛋白酶的独特性质表明，这种热稳定、耐洗涤剂且耐溶剂的蛋白酶在工业应用中具有巨大潜力。
