title: Production and characterization of thermostable metallo-keratinase from newly isolated Bacillus subtilis NRC 3.
abstract: Novel keratinolytic enzyme (32kDa) secreted by a newly isolated Bacillus strain (Bacillus subtilis NRC3) cultivated in medium containing chicken feather meal was purified and partially characterized in a set of biochemical assays. The purification was carried out by applying a protocol of two successive chromatographic steps; cation exchange chromatography on CM-cellulose and gel filtration on sephadex G-75 columns. The purified enzyme showed a specific activity of 5233units/mg protein against 169units/mg protein for crude extract with 31 fold purification. The enzymatic activity of the purified keratinolytic enzyme stimulated by Na(+), K(+), Mg(2+), Ba(2+), Ca(2+), and inhibited by entire tested cations and metalloproteinase inhibitors, indicating that it belongs to metallo-keratinase enzymes. The optimum pH and temperature for the purified enzyme were (7.5, 8.0) and (50, 40°C) when using keratin azure and azocasein as substrates, respectively. The purified enzyme was highly stable at broad pH and temperature ranged (5-10) and (20-60°C), respectively. These results suggest that this keratinase may be a useful alternative and ecofriendly route for handling the abundant amount of waste feathers.
authors: Biological Sciences Department, King Abdulaziz University, Saudi Arabia.
authors: Sanaa E
authors: SE
authors: Tork
authors: Yasser E
authors: YE
authors: Shahein
authors: Amr E
authors: AE
authors: El-Hakim
authors: Azza M
authors: AM
authors: Abdel-Aty
authors: Magda M
authors: MM
authors: Aly
mesh_terms: D001412:Bacillus subtilis / Q000145:classification / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D004789:Enzyme Activation; D004795:Enzyme Stability; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007700:Kinetics; D010447:Peptide Hydrolases / Q000096:biosynthesis / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S; D013696:Temperature
chemical_list: D012336:RNA, Ribosomal, 16S; D010447:Peptide Hydrolases; C035855:keratinase