Wen Yangxuan, Qiang Jiyu, Zhou Guixu, Zhang Xiaobo, Wang Lei, Shi Yawei
Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Institute of Biotechnology, Shanxi University, Taiyuan, China.
Front Microbiol. 2022 Aug 18;13:935072. doi: 10.3389/fmicb.2022.935072. eCollection 2022.
Bacillu DS5 was isolated and identified as a halophilic microbe according to 16S rRNA analysis and the physical and chemical indices of the strain. A new alkaline protease (designated as prot DS5) from DS5 was produced, purified, and characterized. After 12 h incubation in the medium with 1% dextrin, 0.5% NaCl, 2% soluble starch, and 1% yeast extract (pH 7.0), it could reach the maximum enzyme activity (279.74 U/ml). The prot DS5 was stable in the pH range of 6.0-12.0 and the temperature range of 40-60°C, with maximal hydrolytic activities at pH 9 and at 50°C. In the presence of Ca, Mn, Ba, Mg, and Fe, protease activity was enhanced. The prot DS5 was maintained highly stable in NaCl (up to 2.5 mol/L), reducing and oxidizing agents. The prot DS5 also exhibited compatibility in other detergent ingredients, such as non-ionic and anionic surfactants. These properties of prot DS5 make this enzyme suitable for various industrial applications (e.g., detergents and leather).
根据16S rRNA分析以及该菌株的理化指标，分离出芽孢杆菌DS5并鉴定为嗜盐微生物。从DS5中制备、纯化并表征了一种新的碱性蛋白酶（命名为prot DS5）。在含有1%糊精、0.5%氯化钠、2%可溶性淀粉和1%酵母提取物（pH 7.0）的培养基中培养12小时后，它可达到最大酶活性（279.74 U/ml）。prot DS5在pH 6.0 - 12.0和温度40 - 60°C范围内稳定，在pH 9和50°C时具有最大水解活性。在Ca、Mn、Ba、Mg和Fe存在下，蛋白酶活性增强。prot DS5在氯化钠（高达2.5 mol/L）、还原剂和氧化剂中保持高度稳定。prot DS5在其他洗涤剂成分（如非离子和阴离子表面活性剂）中也表现出相容性。prot DS5的这些特性使其适用于各种工业应用（如洗涤剂和皮革）。
