Optimization of Aspergillus niger NRC1ami Pectinase Using Citrus Peel Pectin, Purification, and Thermodynamic Characterization of the Free and Modified Enzyme

• DOI: 10.1007/s12649-022-01838-2
• Publication Date: 2022-06-23T07:02:47Z
• Authors: Mona A. Esawy; Amira A. Gamal; Zeinat Kamel
• Keywords: Aspergillus niger; Pectin

Abstract Enzyme cost and stability are the main problems facing industrial applications. Consequently, Aspergillus niger NRC1ami was isolated from rotten orange recorded a promising pectinase activity (13.8 U/ml). The enzyme optimized using citrus peel pectin as sole carbon source (40 It purified by two steps purifications 632 purification folds. pure showed 14.7% carbohydrate content consists of 15 amino acids. Glutamic acid major (22%) followed leucine (10.67%) threonine minor (2.70%). A. conjugated covalent coupling to sodium periodate (NaIO 4 ) activated polysaccharides. Galactomannan highest recovered (85%) 94.34% reduction in viscosity. optimum temperature for shifted 40 45 °C after conjugation process. Also, free its at pH 5 compared 4, form case. thermal greatly improved modification process reduced activation energy 36%, prolonged half-life 5.6-fold 60 °C, increase deactivation (Ed) about 19% comparison form. D value increased 13.2-fold 50 Gibbs's (ΔG) process, while enthalpy (ΔH) entropy (ΔS) decreased. Na + Zn 2+ had stimulating effect on both forms. Graphical