Microbial proteases are relevant biocatalysts with diverse applications. Production of protein hydrolysates is recently focused, since they might display biological activities. Therefore, the extracellular protease from Bacillus sp. CL18 was partially purified through ammonium sulfate precipitation (25–50% saturation) and gel filtration chromatography, with a 60.7-fold purification (40,593 U/mg protein) and 21.3% recovery. The partially purified protease (PPP) was characterized as a serine protease, with optimal activity at 51–59 °C and pH 7.4–8.8 and low thermal stability. Thermal inactivation followed first-order kinetics. PPP depended on Ca²⁺ for higher thermal stability, depicted by increases in half-lives (t_1/2), activation energy (E_a), and free energy (ΔG^#) for kinetic inactivation. PPP preferentially hydrolyzed casein > soy protein isolate (SPI) >>> keratinous materials. SPI hydrolysis by PPP was further investigated, and the obtained hydrolysates exhibited increased in vitro bioactivities. Hydrolysates displayed antioxidant capacities through the scavenging of synthetic organic radicals and Fe³⁺-reducing ability. In addition, hydrolysates inhibited the activities of dipeptidyl peptidase IV (DPP IV) and angiotensin-converting enzyme (ACE), suggesting antidiabetic and antihypertensive potentials, respectively. From its biochemical properties, PPP might be used to produce protein hydrolysates with multifunctional bioactivities. Both PPP and SPI hydrolysates can find applications in food biotechnology.

微生物蛋白酶是具有多种应用的相关生物催化剂。蛋白质水解产物的生产近来受到关注，因为它们可能显示出生物活性。因此，芽孢杆菌属的细胞外蛋白酶。CL18通过硫酸铵沉淀（饱和度25–50％）和凝胶过滤色谱法进行部分纯化，纯化率为60.7倍（40,593 U / mg蛋白质），回收率为21.3％。部分纯化的蛋白酶（PPP）被表征为丝氨酸蛋白酶，在51–59°C和pH 7.4–8.8下具有最佳活性，并且热稳定性低。热失活遵循一级动力学。PPP依赖于Ca ²⁺具有更高的热稳定性，其表现为半衰期（t _1/2），活化能（tE _a），以及用于动力学失活的自由能（ΔG ^＃）。PPP优先水解酪蛋白>大豆分离蛋白（SPI）>>>角蛋白。进一步研究了通过PPP进行的SPI水解，所得水解产物显示出更高的体外生物活性。水解产物通过清除合成有机自由基和Fe ³⁺表现出抗氧化能力-还原能力。此外，水解产物抑制二肽基肽酶IV（DPP IV）和血管紧张素转换酶（ACE）的活性，分别提示有降糖和降压的潜力。从其生化特性来看，PPP可用于生产具有多功能生物活性的蛋白质水解产物。PPP和SPI水解产物均可在食品生物技术中找到应用。