Zhang Rong-Xian, Gong Jin-Song, Su Chang, Zhang Dan-Dan, Tian Hua, Dou Wen-Fang, Li Heng, Shi Jin-Song, Xu Zheng-Hong
The Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, PR China; School of Pharmaceutical Science, Jiangnan University, Wuxi 214122, PR China.
School of Pharmaceutical Science, Jiangnan University, Wuxi 214122, PR China.
Int J Biol Macromol. 2016 Dec;93(Pt A):843-851. doi: 10.1016/j.ijbiomac.2016.09.063. Epub 2016 Sep 17.
Dehairing is a high pollution process in leather industry. Conventionally, the lime-sulfide mediated chemical process for dehairing would lead to the discharge of pollutants and corrosion of industrial equipment. Concerning these problems, keratinase has become a promising candidate for dehairing process in recent years. In this study, a keratinase-producing bacterium was isolated from sheepfold soil and identified as Brevibacillus parabrevis CGMCC 10798 based on the biochemical characteristics and molecular identification. The keratinase was purified to electrophoretic homogeneity with 17.19% of recovery, 13.18 folds of purification and an estimated molecular weight of 28kDa. The enzyme exhibited high keratinase activity and no collagenase activity. Besides, the keratinase showed optimal activity at 60°C and pH 8.0. The enzyme activity could be significantly increased in the presence of Na and Ca. And it was inhibited by EDTA, and PMSF, which indicated that the keratinase belongs to serine-metallo protease. The enzyme could remain stable in the presence of surfactants. Especially, 5mM Tween 40 and Triton 100 could improve the activity by 11% and 30%, respectively. Moreover, B. parabrevis keratinase could completely dehair goat wool within 7h, which indicated its application potential in leather industry.
脱毛是皮革工业中污染严重的工序。传统上，石灰硫化物介导的化学脱毛工艺会导致污染物排放和工业设备腐蚀。针对这些问题，近年来角质酶成为脱毛工艺的一个有前景的选择。在本研究中，从羊圈土壤中分离出一株产角质酶的细菌，根据生化特性和分子鉴定，将其鉴定为短短芽孢杆菌CGMCC 10798。该角质酶经纯化后达到电泳纯，回收率为17.19%，纯化倍数为13.18倍，估计分子量为28kDa。该酶表现出高角质酶活性，无胶原酶活性。此外，角质酶在60℃和pH 8.0时表现出最佳活性。在Na和Ca存在下，酶活性可显著提高。它受到EDTA和PMSF的抑制，这表明该角质酶属于丝氨酸-金属蛋白酶。该酶在表面活性剂存在下可保持稳定。特别是，5mM吐温40和曲拉通100可分别使活性提高11%和30%。此外，短短芽孢杆菌角质酶可在7小时内完全脱去山羊毛，这表明其在皮革工业中的应用潜力。
