title: Keratinolytic proteinase from Bacillus thuringiensis AD-12.
abstract: A new isolated strain noted to produce a novel detergent-stable serine keratinolytic proteinase and identified as Bacillus thuringiensis AD-12. Native keratinolytic proteinase from B. thuringiensis (BtKER) was purified and characterized. The purified BtKER enzyme is a monomer with a molecular mass of 39kDa. Biochemical characterization assays revealed that the BtKER attained optimal activity at pH 7 and 30°C. Residual activity after 1h incubation at 50°C was higher than 80%. The enzyme was activated and stabilized by Mn(2+) and Li(+) metal ions but inactivated by organic solvents. Purified BtKER showed the highest substrate specificity toward keratin from wool>sodium caseinate>collagen>BSA>gelatin in descending order. BtKER is the first reported keratinolytic proteinase from B. thuringiensis and obtained results suggested that new characterized enzyme can be a powerful biocatalyst in peptide production associated to hydrolysis of keratinous and/or keratin-like waste.
authors.affiliation: Department of Microbiology and Biotechnology, Faculty of Natural Sciences, Vilnius University, M. K. Čiurlionio 21/27, LT-03101 Vilnius, Lithuania. Electronic address: audrius.gegeckas@gf.vu.lt.
authors.forename: Audrius
authors.initials: A
authors.lastname: Gegeckas
authors.affiliation: Department of Microbiology and Biotechnology, Faculty of Natural Sciences, Vilnius University, M. K. Čiurlionio 21/27, LT-03101 Vilnius, Lithuania.
authors.forename: Renata
authors.initials: R
authors.lastname: Gudiukaitė
authors.affiliation: Department of Microbiology and Biotechnology, Faculty of Natural Sciences, Vilnius University, M. K. Čiurlionio 21/27, LT-03101 Vilnius, Lithuania.
authors.forename: Donaldas
authors.initials: D
authors.lastname: Citavicius
mesh_terms: D000818:Animals; D001413:Bacillus thuringiensis / Q000201:enzymology*; D002417:Cattle; D006868:Hydrolysis; D010447:Peptide Hydrolases / Q000378:metabolism*; D011506:Proteins / Q000737:chemistry / Q000378:metabolism; D012995:Solubility
chemical_list: D011506:Proteins; D010447:Peptide Hydrolases; C035855:keratinase
keywords: Bacillus thuringiensis AD-12; Keratin biodegradation; Keratinolytic proteinase