title: Thermostable keratinase from Bacillus pumilus KS12: production, chitin crosslinking and degradation of Sup35NM aggregates.
abstract: Production of thermostable keratinase from Bacillus pumilus KS12 was enhanced up to seven fold by statistical methods. The enzyme was partially purified by ultrafiltration followed by thermal precipitation with purity of 3.2-fold and recovery of 89%. Keratinase was immobilized using covalent method by crosslinking 2 mg protein (688 U/mg) onto 1g chitin activated with 2.5% (v/v) glutaraldehyde for 60 min. Its comparative biochemical studies with that of free keratinase revealed the shift in optimum pH with increased stability towards pH from 9.0 to 10.0 and temperature. Also, it showed statistically significant improved hydrolysis of a number of soluble and insoluble substrates in comparison to free keratinase. Owing to improved catalytic efficiency of immobilized keratinase, its potential for degradation of Sup35NM was evaluated, where 100 μg of enzyme could degrade 60 μg Sup35NM after 60 min at pH 7.0 and 37°C.
authors: Department of Microbiology, University of Delhi, South Campus, New Delhi, India.
authors: Rinky
authors: R
authors: Rajput
authors: Rani
authors: R
authors: Gupta
mesh_terms: D000818:Animals; D001407:Bacillus / Q000201:enzymology*; D018533:Biomass; D002645:Chickens; D002686:Chitin / Q000378:metabolism*; D003432:Cross-Linking Reagents / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D004795:Enzyme Stability; D004800:Enzymes, Immobilized / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D010447:Peptide Hydrolases / Q000096:biosynthesis*; D011328:Prions / Q000378:metabolism*; D020836:Protein Structure, Quaternary; D059748:Proteolysis; D015203:Reproducibility of Results; D013379:Substrate Specificity; D013696:Temperature
chemical_list: D003432:Cross-Linking Reagents; D004800:Enzymes, Immobilized; D011328:Prions; D002686:Chitin; D010447:Peptide Hydrolases; C035855:keratinase