Department of Medicinal and Applied Chemistry, Kaohsiung Medical University, Kaohsiung City, 807, Taiwan.
Department of Biomedical Science and Environmental Biology, Kaohsiung Medical University, Kaohsiung City, 807, Taiwan.
Sci Rep. 2021 Jun 7;11(1):12007. doi: 10.1038/s41598-021-90375-4.
Microbial secondary metabolites from extreme environments like hydrothermal vents are a promising source for industrial applications. In our study the protease gene from Bacillus cereus obtained from shallow marine hydrothermal vents in the East China Sea was cloned, expressed and purified. The protein sequence of 38 kDa protease SLSP-k was retrieved from mass spectrometry and identified as a subtilisin serine proteinase. The novel SLSP-k is a monomeric protein with 38 amino acid signal peptides being active over wide pH (7-11) and temperature (40-80 °C) ranges, with maximal hydrolytic activities at pH 10 and at 50 °C temperature. The hydrolytic activity is stimulated by Ca, Co, Mn, and DTT. It is inhibited by Fe, Cd, Cu, EDTA, and PMSF. The SLSP-k is stable in anionic, non-anionic detergents, and solvents. The ability to degrade keratin in chicken feather and hair indicates that this enzyme is suitable for the degradation of poultry waste without the loss of nutritionally essential amino acids which otherwise are lost in hydrothermal processing. Therefore, the proteinase is efficient in environmental friendly bioconversion of animal waste into fertilizers or value added products such as secondary animal feedstuffs.
从深海热液喷口等极端环境中分离得到的微生物次生代谢产物是工业应用的有前途的来源。在我们的研究中，从东海浅海热液喷口获得的蜡样芽孢杆菌的蛋白酶基因被克隆、表达和纯化。从质谱法中检索到 38 kDa 蛋白酶 SLSP-k 的蛋白质序列，并将其鉴定为枯草杆菌蛋白酶。新型 SLSP-k 是一种单体蛋白，具有 38 个氨基酸的信号肽，在较宽的 pH（7-11）和温度（40-80°C）范围内具有活性，在 pH10 和 50°C 温度下具有最大的水解活性。水解活性受 Ca、Co、Mn 和 DTT 刺激。它被 Fe、Cd、Cu、EDTA 和 PMSF 抑制。SLSP-k 在阴离子和非阴离子洗涤剂以及溶剂中稳定。在鸡毛和头发中角蛋白的降解能力表明，该酶适用于家禽废物的降解，而不会像在热液处理中那样丢失营养必需氨基酸。因此，蛋白酶在环保的动物废物生物转化为肥料或增值产品（如二级动物饲料）方面非常有效。
