title: Extracellular expression of keratinase from Bacillus licheniformis ER-15 in Escherichia coli.
abstract: Keratinase (ker BL) from Bacillus licheniformis ER-15 was cloned into vector pEZZ18 for extracellular expression in Escherichia coli HB101. Recombinant keratinase was secreted with high specific activity (75 units/mg) under non-inducible conditions after 36 h at 37 degrees C and 300 rpm in a shake flask. Protein was concentrated and, subsequently, purified by ion-exchange chromatography using Q-sepharose with 95.8% yield. The recombinant keratinase was a serine protease and most active in the pH range of 8-12 and at 60 degrees C. The enzyme was stable over a wide pH range of 4-12 for 3 h. ker BL degraded bovine serum albumin, casein, azocasein, gelatin, and feather. E. coli HB101 harboring pEZZ18 ker BL2 degraded chicken feather completely within 24 h at 37 degrees C.
authors.affiliation: Department of Microbiology, University of Delhi, New Delhi, India.
authors.forename: Ekta
authors.initials: E
authors.lastname: Tiwary
authors.forename: Rani
authors.initials: R
authors.lastname: Gupta
mesh_terms: D000818:Animals; D001407:Bacillus / Q000737:chemistry / Q000201:enzymology*; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D002417:Cattle; D002645:Chickens; D004795:Enzyme Stability; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism; D005110:Extracellular Space / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D005241:Feathers / Q000737:chemistry; D015870:Gene Expression; D007700:Kinetics; D010447:Peptide Hydrolases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D012710:Serum Albumin, Bovine / Q000737:chemistry; D013379:Substrate Specificity
chemical_list: D001426:Bacterial Proteins; D012710:Serum Albumin, Bovine; D010447:Peptide Hydrolases; C035855:keratinase