Cao Zhang-Jun, Zhang Qi, Wei Dong-Kai, Chen Li, Wang Jing, Zhang Xing-Qun, Zhou Mei-Hua
Key Laboratory of Science and Technology of Eco-Textile, Donghua University, Ministry of Education, 201620, Shanghai, China.
J Ind Microbiol Biotechnol. 2009 Feb;36(2):181-8. doi: 10.1007/s10295-008-0469-8. Epub 2009 Jan 10.
A feather-degrading bacterium was isolated from poultry decomposition feathers in China. The strain, named L1, showed significant feather-degrading activity because it grew and reproduced quickly on basal medium containing 10 g/L of native feather as the source of energy, carbon, and nitrogen. According to the phenotypic characteristics and 16S rRNA profile, the isolate belongs to Stenotrophomonas maltophilia. Keratinase activity of the isolate was determined during cultivation on raw feathers at different temperatures and initial pH. Maximum growth and feather-degrading activity of the bacterium were observed at 40 degrees C and initial pH ranging from 7.5 to 8.0. The crude enzyme was purified by ammonium sulphate precipitation, Sephadex G-100 chromatographic and ceramic hydroxyapatite (CHT) chromatographic. Its molecular mass estimated as 35.2 kDa in SDS-PAGE. The enzyme had an optimum activity at the pH was 7.8 and the temperature was 40 degrees C. The keratinase was wholly inhibited by a serine protease inhibitor, PMSF. Its activity was activated or inhibited by different metal ions. The keratinase activity of enzyme from strain L1 functioned on different keratins, such as feather, hair, wool, horn, and so on.
从中国家禽腐烂羽毛中分离出一株羽毛降解细菌。该菌株命名为L1，在以10 g/L天然羽毛作为能量、碳源和氮源的基础培养基上生长繁殖迅速，表现出显著的羽毛降解活性。根据表型特征和16S rRNA谱，该分离株属于嗜麦芽窄食单胞菌。在不同温度和初始pH条件下，在生羽毛上培养期间测定了该分离株的角蛋白酶活性。在40℃和初始pH值为7.5至8.0的范围内观察到该细菌的最大生长和羽毛降解活性。通过硫酸铵沉淀、Sephadex G - 100色谱和陶瓷羟基磷灰石（CHT）色谱对粗酶进行纯化。在SDS - PAGE中其分子量估计为35.2 kDa。该酶在pH为7.8、温度为40℃时具有最佳活性。该角蛋白酶完全被丝氨酸蛋白酶抑制剂PMSF抑制。其活性被不同金属离子激活或抑制。菌株L1的酶对角蛋白如羽毛、毛发、羊毛、角等具有角蛋白酶活性。
