To obtain proteases with high collagenolytic activity, 400 bacteria isolates were screened. The secreted proteases from Bacillus subtilis subsp. subtilis B13 (isolated from beef butchery) and B. siamemsis S6 (isolated from soil) which showed the two highest activity to hydrolyze collagen from bovine Achilles tendon were partially characterized. After enzyme fractionation, both enzymes had the optimum pH for the collagenolytic activity at pH 7.5. However, the optimum temperature of enzyme produced by S6 (60 °C) was higher than B13 (50 °C). The inhibitor study revealed that these proteases were mainly a member of serine proteases and some metalloproteases. Both enzymes were able to degrade collagen with multiple cleavage sites as observed by electrophoretic patterns. In contrast to papain and bromelain, these collagenolytic proteases showed strong hydrolysis toward collagen and elastin as well as beef intramuscular collagen with low beef myofibrillar protein degradation. Moreover, the lower digestion of myofibrillar protein and casein by these enzymes as compared with collagenase from Clostridium histolyticum were observed. These proteases could be applied as a meat tenderizer when collagen or connective tissue protein was responsible for the meat toughness.

为了获得具有高胶原分解活性的蛋白酶，筛选了400个细菌分离株。枯草芽孢杆菌亚种分泌的蛋白酶。枯草芽孢杆菌B13（从牛肉屠宰场中分离）和B. siamemsis部分表征了S6（从土壤中分离），其具有两种最高的水解牛跟腱胶原蛋白的活性。酶分级分离后，两种酶均具有在pH 7.5时具有最佳胶原溶解活性的pH。但是，S6（60°C）产生的酶的最佳温度高于B13（50°C）。抑制剂研究表明，这些蛋白酶主要是丝氨酸蛋白酶和某些金属蛋白酶的成员。如电泳图所示，两种酶都能够降解具有多个切割位点的胶原蛋白。与木瓜蛋白酶和菠萝蛋白酶相反，这些胶原蛋白水解蛋白酶显示出对胶原蛋白和弹性蛋白以及牛肉肌内胶原蛋白的强水解性，而牛肉肌原纤维蛋白降解率低。此外，观察到溶组织梭状芽胞杆菌。当胶原蛋白或结缔组织蛋白负责肉的韧性时，这些蛋白酶可以用作嫩肉剂。