title: Expression and characterization of extreme alkaline, oxidation-resistant keratinase from Bacillus licheniformis in recombinant Bacillus subtilis WB600 expression system and its application in wool fiber processing.
abstract: A keratin-degrading bacterium of Bacillus licheniformis BBE11-1 was isolated and its ker gene encoding keratinase with native signal peptide was cloned and expressed in Bacillus subtilis WB600 under the strong P HpaII promoter of the pMA0911 vector. In the 3-L fermenter, the recombinant keratinase was secreted with 323 units/mL when non-induced after 24 h at 37 °C. And then, keratinase was concentrated and purified by hydrophobic interaction chromatography using HiTrap Phenyl-Sepharose Fast Flow. The recombinant keratinase had an optimal temperature and the pH at 40 °C and 10.5, respectively, and was stable at 10-50 °C and pH 7-11.5. We found this enzyme can retained 80 % activity after treated 5 h with 1 M H2O2, it was activated by Mg(2+), Co(2+) and could degraded broad substrates such as degraded feather, bovine serum albumin, casein, gelatin, the keratinase was considered to be a serine protease. Coordinate with Savinase, the keratinase could efficient prevent shrinkage and eliminate fibres of wool, which showed its potential in textile industries and detergent industries.
authors.affiliation: Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China. liu8bai6hong@163.com
authors.forename: Baihong
authors.initials: B
authors.lastname: Liu
authors.forename: Juan
authors.initials: J
authors.lastname: Zhang
authors.forename: Ben
authors.initials: B
authors.lastname: Li
authors.forename: Xiangru
authors.initials: X
authors.lastname: Liao
authors.forename: Guocheng
authors.initials: G
authors.lastname: Du
authors.forename: Jian
authors.initials: J
authors.lastname: Chen
mesh_terms: D000818:Animals; D001407:Bacillus / Q000737:chemistry / Q000201:enzymology* / Q000235:genetics / Q000302:isolation & purification; D001412:Bacillus subtilis / Q000235:genetics* / Q000378:metabolism; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D004795:Enzyme Stability; D015870:Gene Expression; D006863:Hydrogen-Ion Concentration; D010084:Oxidation-Reduction; D010447:Peptide Hydrolases / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D012988:Soil Microbiology; D013379:Substrate Specificity; D013696:Temperature; D013783:Textile Industry; D014935:Wool / Q000737:chemistry*
chemical_list: D001426:Bacterial Proteins; D010447:Peptide Hydrolases; C035855:keratinase