Recombinant expression and biochemical characterization of a novel keratinase BsKER71 from feather degrading bacterium Bacillus subtilis S1-4

AMB Express

Pan Xu¹  Weimin Ni¹  Youwen Hu¹  Xiang Tao¹  Bin Yong¹  Qiuju Xiao¹  Xueting Fei¹  Xinyi He¹  Huanhuan Shao¹  Hong Feng² 

[1] College of Life Sciences, Sichuan Normal University;College of Life Sciences, Sichuan University;

关键词: Feather degradation;    Keratinase, BsKER71;    Bacillus subtilis S1-4;   

DOI  :  10.1186/s13568-019-0939-6

来源: DOAJ

【 摘 要 】

Abstract Bacillus subtilis S1-4, isolated from chicken feather could efficiently degrade feathers by secreting several extracellular proteases. In order to get insight into the individual protease involved in keratin hydrolysis, a keratinase designed as BsKER71 was cloned and expressed in Bacillus subtilis WB600. In silico analysis revealed that BsKER71 protein contained a mature protein of 36.1 kDa. Further, purified BsKER71 could hydrolyze a variety of natural proteins, such as fibrous protein, collagen protein, casein, keratin and bovine serum albumin. In addition, this keratinase exhibited high enzyme activity in a wide range of pH and optimal pH of 10.0 and 9.0 in the hydrolysis of casein and keratin, respectively. Similarly, the optimal temperature was 55 °C and 50 °C for the hydrolysis of above two substrates, respectively. The hydrolytic activity was significantly inhibited by phenylmethanesulfonyl fluoride (PMSF), indicating the presence of serine residue in the active site. Moreover, ethylenediaminetetraacetic acid (EDTA) and phenanthroline moderately inhibited the hydrolytic activity. The catalytic activity was stimulated by Mg2+ and Ca2+, but greatly inhibited by Cu2+. Furthermore, several chemicals exhibited different effects on the hydrolysis of casein and keratin by BsKER71. These results provided a better understanding of BsKER71 from feather degrading bacterium B. subtilis S1-4.

【 授权许可】

Unknown