National Center for Biotechnology, 13/5 Korgalzhyn Road, 010000, Astana, Kazakhstan.
Faculty of Natural Sciences, L.N. Gumilyev Eurasian National University, 2 Kanysh Satpayev Street, 010008, Astana, Kazakhstan.
Sci Rep. 2024 Sep 30;14(1):22621. doi: 10.1038/s41598-024-73468-8.
Bacillus paralicheniformis T7, which exhibits high proteolytic and keratinolytic activities, was isolated from soil in Kazakhstan. Its secreted proteases were thermostable and alkaline, demonstrating maximum activity at 70 °C and pH 9.0. The proteases and keratinases of this strain were sensitive to Ni, Co, Mn, and Cd, with Cu, Co and Cd negatively affecting keratinolytic activity, and Fe ions have a strong inhibitory effect on proteolytic and keratinolytic activity. Seven proteases were identified in the enzymatic extract of B. paralicheniformis T7: four from the serine peptidase family and three from the metallopeptidase family. The proteases hydrolyzed 1 mg of casein, hemoglobin, gelatin, ovalbumin, bovine serum albumin, or keratin within 15 s to 30 min. The high keratinolytic activity of this strain was confirmed through the degradation of chicken feathers, horns, hooves, wool, and cattle hide. Chicken feathers were hydrolyzed in 4 days, and the degrees of hydrolysis for cattle hide, wool, hoof, and horn after 7 days of cultivation were 97.2, 34.5, 29.6, and 3.6%, respectively. During submerged fermentation with feather medium in a laboratory bioreactor, the strain secreted enzymes with 249.20 ± 7.88 U/mL protease activity after 24 h. Thus, B. paralicheniformis T7 can be used to produce proteolytic and keratinolytic enzymes for application in processing proteinaceous raw materials and keratinous animal waste.
芽孢八叠球菌 T7 具有较高的蛋白水解和角蛋白水解活性，从哈萨克斯坦的土壤中分离得到。其分泌的蛋白酶具有热稳定性和碱性，在 70°C 和 pH9.0 时表现出最大活性。该菌株的蛋白酶和角蛋白酶对 Ni、Co、Mn 和 Cd 敏感，Cu、Co 和 Cd 对角蛋白水解活性有负影响，而 Fe 离子对蛋白水解和角蛋白水解活性有很强的抑制作用。从芽孢八叠球菌 T7 的酶提取物中鉴定出 7 种蛋白酶：4 种属于丝氨酸肽酶家族，3 种属于金属肽酶家族。蛋白酶在 15s 到 30min 内可水解 1mg 酪蛋白、血红蛋白、明胶、卵清蛋白、牛血清白蛋白或角蛋白。该菌株对角质的高水解活性通过对鸡毛、牛角、蹄、羊毛和牛皮的降解得到了证实。鸡毛在 4 天内被水解，牛皮、羊毛、蹄和角在培养 7 天后的水解度分别为 97.2%、34.5%、29.6%和 3.6%。在实验室生物反应器中进行羽毛培养基的液体发酵时，该菌株在 24 小时后分泌出 249.20±7.88 U/mL 蛋白酶活性的酶。因此，芽孢八叠球菌 T7 可用于生产蛋白水解酶和角蛋白酶，用于处理蛋白质原料和角蛋白动物废物。
