Hashem, A., Abdel-Fattah, A., Ismail, S., El-Gamal, M., Esawy, M., Emran, M. (2018). Optimization, Characterization and Thermodynamic Studies on B. licheniformis ALW1 Keratinase. Egyptian Journal of Chemistry, 61(4), 591-607. doi: 10.21608/ejchem.2018.3379.1287
Amal Mohamed Hashem; Azza Abdel-Fattah; Siham Ismail; Mamdouh El-Gamal; Mona Esawy; Mohamed Abdelrahman Emran. "Optimization, Characterization and Thermodynamic Studies on B. licheniformis ALW1 Keratinase". Egyptian Journal of Chemistry, 61, 4, 2018, 591-607. doi: 10.21608/ejchem.2018.3379.1287
Hashem, A., Abdel-Fattah, A., Ismail, S., El-Gamal, M., Esawy, M., Emran, M. (2018). 'Optimization, Characterization and Thermodynamic Studies on B. licheniformis ALW1 Keratinase', Egyptian Journal of Chemistry, 61(4), pp. 591-607. doi: 10.21608/ejchem.2018.3379.1287
Hashem, A., Abdel-Fattah, A., Ismail, S., El-Gamal, M., Esawy, M., Emran, M. Optimization, Characterization and Thermodynamic Studies on B. licheniformis ALW1 Keratinase. Egyptian Journal of Chemistry, 2018; 61(4): 591-607. doi: 10.21608/ejchem.2018.3379.1287
Optimization, Characterization and Thermodynamic Studies on B. licheniformis ALW1 Keratinase
1Chemistry of Natural and Microbial Products Department, National Research Centre, Dokki, Giza, Egypt.
2Department of Botany and Microbiology. Faculty of Science (Boys), Al-Azhar University, Cairo, Egypt
Receive Date: 04 April 2018,
Revise Date: 16 April 2018,
Accept Date: 22 April 2018
Abstract
Optimization of B. licheniformis ALW1 keratinase was investigated by using a Plackett – Burman design (PBD) and Central Composite Design (CCD). PBD showed that galactose, inoculum size and corn steep liquorwere the most effectivevariables played a rolein improving the enzyme productivity (87.65U/mL). CCD results recorded an increase in enzyme productivity to about1.4-fold compared to the basal medium (99.1 U/mL). The optimum activity for the partial purified enzyme was obtained at pH 8.5 and 70˚C. The activation and deactivation energy were calculated to be25.37 kJmol-1 and73.38 kJmol-1 respectively. The half-life time was 1380,690,530, and383 min. at 50˚C,55˚C,60˚C and 65˚C respectively. Also, D values were 4600,2300,1769, 1277min. at the same degree respectively. ∆G° (kJmol-1) kept relatively constant between 50-60˚C (191.49 kJmol-1-193.31 kJmol-1) and noticeably increase at 65˚C (212.86 kJmol-1). ∆H° (kJmol-1) recorded minor decrease by the increase of temperature. Approximately, most of the tested metals ions have stimulation effect in enzyme activityand MgSO4.H2O was the best (146%). Among all the tested detergents tween 80 retained 97% of original enzyme activity. DMSO increased the enzyme activity about 11%, while propanol and acetonitrile reduced the enzyme activity to about 14% and 10% respectively. All the reducing agents had a stimulating effect on enzyme activity with variable degrees. The enzyme (980 U) had the ability to hydrolyze 74% of the feather to nutritional valuable protein.
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