A Surfactant-stable Bacillus pumilus K9 α-Keratinase and Its Potential Application in Detergent Industry  

作　　者：GONG Jinsong WANG Yue ZHANG Dandan LI Heng ZHANG Xiaomei ZHANG Rongxian LU Zhenming XU Zhenghong SHI Jinsong 

机构地区：[1]School of Pharmaceutical Science, Jiangnan University, Wuxi 214122, P. R. China

出　　处：《Chemical Research in Chinese Universities》2015年第1期91-97,共7页高等学校化学研究（英文版）

基　　金：Supported by the National High Technology Research and Development Program of China（No.2012AA022204C） and the National Natural Science Foundation of China（No.21406088）.

摘　　要：An a-keratinase producing strain was isolated with wool as the sole carbon and nitrogen source and identified as Bacilluspumilus K9. The major amino acids liberated from the keratin degradation of wool by B. pumilus K9 were glutamic acid and leucine. The a-keratinase was purified to electrophoretic homogeneity with a molecular weight of 32000. The purified enzyme exhibits an optimum activity at 60 ℃ and pH=9.0. It was stable at pH values between 8 and 11. Bacillas pumilus keratinase displays a high activity towards casein, keratin, wool and feather, which indicates its wide application range. The keratinase was completely inhibited by phenylmethyl-sulfonyl fluoride（PMSF） and β-mercaptoethanol, and moderately inhibited by ethylemediamine-tetraacetic acid（EDTA）, suggesting it is a metallo-cysteine keratinase. This enzyme could remain stable that could even be promoted in the presence of surfactants, including sodium dodecyl sulfate（SDS）, Tween and Triton. And Tween 40 and Triton X-100 could substantially enhance the activity of the enzyme by 54% and 35%, respectively. It may indicate the prominent feature of the keratinase to tolerate surfactants. The enzymatic properties distinguish this keratinase from others in the literature. Furthermore, this enzyme is extremely stable in the presence of a commercially available detergent with 1% concentration. Detergents ARIEL, Bluemoon and WhiteCat can enhance the activity of the keratinase by 43.56%, 15.22%, and 22.48%, respectively.An a-keratinase producing strain was isolated with wool as the sole carbon and nitrogen source and identified as Bacilluspumilus K9. The major amino acids liberated from the keratin degradation of wool by B. pumilus K9 were glutamic acid and leucine. The a-keratinase was purified to electrophoretic homogeneity with a molecular weight of 32000. The purified enzyme exhibits an optimum activity at 60 ℃ and pH=9.0. It was stable at pH values between 8 and 11. Bacillas pumilus keratinase displays a high activity towards casein, keratin, wool and feather, which indicates its wide application range. The keratinase was completely inhibited by phenylmethyl-sulfonyl fluoride（PMSF） and β-mercaptoethanol, and moderately inhibited by ethylemediamine-tetraacetic acid（EDTA）, suggesting it is a metallo-cysteine keratinase. This enzyme could remain stable that could even be promoted in the presence of surfactants, including sodium dodecyl sulfate（SDS）, Tween and Triton. And Tween 40 and Triton X-100 could substantially enhance the activity of the enzyme by 54% and 35%, respectively. It may indicate the prominent feature of the keratinase to tolerate surfactants. The enzymatic properties distinguish this keratinase from others in the literature. Furthermore, this enzyme is extremely stable in the presence of a commercially available detergent with 1% concentration. Detergents ARIEL, Bluemoon and WhiteCat can enhance the activity of the keratinase by 43.56%, 15.22%, and 22.48%, respectively.

关 键 词：a-Keratinase Bacilluspumilus K9 Wool degradation Surfactant stability DETERGENT 

分 类 号：TQ423[化学工程] TQ920.1[轻工技术与工程—发酵工程]