Kinetic and thermodynamic characterization of keratinolytic protease from chicken feather waste degrading B. subtilis ES5

Kinetic and thermodynamic characterization of enzymes is of great important for understanding their industrial applications. The main objective of this study was to produce, purify and study the kinetic and thermodynamic properties of keratinase from B. subtilis ES5. Specific activity of the enzyme was improved by 126.16 % and 140.11 % using ammonium sulfate and dialysis purification methods, respectively. The activation energy (E-a), Gibbs free energy (Delta G(not equal)), entropy (Delta S-not equal), enthalpy (Delta H-not equal), free energy of substrate binding (Delta G(E-S)(not equal)), free energy of transition state formation (Delta G(E-T)(not equal)), and temperature coefficient (Q(10)) for casein hydrolysis were 17.59 KJ/ mol, 66.11 KJ/mol, - 160.88 J/mol/k, 14.95 KJ/mol, 2.61 KJ/mol, - 9.21 KJ/mol, and 1.62, respectively. Thermal denaturation energy for keratinase was 110.83 KJ/mol. Kinetic studies revealed good enzyme-substrate complex formation and spontaneous conversion to product. Thermodynamic parameters indicate a relatively thermostable enzyme. These properties suggest that the present keratinase can be a potential candidate for use in different biotechnological applications.