title: A novel serine metallokeratinase from a newly isolated Bacillus pumilus A1 grown on chicken feather meal: biochemical and molecular characterization.
abstract: A keratinolytic enzyme (KerA1) secreted by a newly isolated Bacillus pumilus strain A1 cultivated in medium containing chicken feather meal was purified and characterized, and the gene was isolated and sequenced. The molecular mass of the purified enzyme was estimated to be 34,000 Da by sodium dodecyl sulfate (SDS) polyacrylamide gel electrophoresis and gel filtration. The optimum pH and temperature for the purified keratinase were 9.0 and 60 degrees C, respectively, using keratin as a substrate. KerA1 showed a high stability towards nonionic surfactants. It was found to be relatively stable toward the strong anionic surfactant (SDS). The deduced amino acid sequence of the keratinase KerA1 differs from both the organic solvent tolerant protease of B. pumilus 115b and the dehairing protease of B. pumilus UN-31-C-42 by one and nine amino acids, respectively. These results suggest that this keratinase may be a useful alternative and ecofriendly route for handling the abundant amount of waste feathers and for applications in detergent formulations.
authors.affiliation: Laboratoire de Génie Enzymatique et de Microbiologie, Ecole Nationale d'Ingénieurs de Sfax, BP 1173, 3038 Sfax, Tunisia. nahedfakh_zouari@yahoo.fr
authors.forename: Nahed
authors.initials: N
authors.lastname: Fakhfakh-Zouari
authors.forename: Noomen
authors.initials: N
authors.lastname: Hmidet
authors.forename: Anissa
authors.initials: A
authors.lastname: Haddar
authors.forename: Safia
authors.initials: S
authors.lastname: Kanoun
authors.forename: Moncef
authors.initials: M
authors.lastname: Nasri
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001407:Bacillus / Q000201:enzymology* / Q000302:isolation & purification; D002645:Chickens; D017124:Conserved Sequence; D004795:Enzyme Stability; D005241:Feathers; D006863:Hydrogen-Ion Concentration; D008969:Molecular Sequence Data; D010447:Peptide Hydrolases / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D016415:Sequence Alignment; D013379:Substrate Specificity; D013696:Temperature
chemical_list: D010447:Peptide Hydrolases; C035855:keratinase