| Abstrakt: |
Thermo-instability affects enzymes' efficiency in the industry. This study explored the thermodynamic and kinetic properties of Trichoderma longibrachiatum MT321074 pectinase, to ascertain its potential for industrial application. Trichoderma longibrachiatum MT321074 was isolated from decaying mango fruits and identified using the 18S rDNA sequencing technique. The Trichoderma longibrachiatum MT321074 pectinase was purified 5.61 fold with a specific activity and yield of 2.86 U/mg and 17.63%. The pH and temperature optima were 5.0 and 40°C. The Michaelis constant, KM, and maximum velocity, Vmax were 1.0 mg/ml and 82.64 µmol/min. The enzyme retained 92%, 87%, and 72% of its original activity after 2 h at 30°C, 40°C, and 50°C, respectively. At 60°C, 70°C and 80°C, the enzyme lost 38%, 65%, and 73% of its activity after 120 min. The enzyme's melting temperature (Tm) was 64°C. The rates of thermal inactivation (Kd) were low at all temperatures tested. The activation energy of inactivation (Ea) was 50.30 KJ/mol-1. The D-values and half-life (t1/2) decreased from 3838.33 to 261.70 min and 1155.00 to 78.75 min, respectively. The enzyme had a high Z-value of 42°C. The Gibbs free energy (ΔGin) increased with a rise in temperature. High enthalpy changes (ΔHin) were obtained at all temperatures tested. The entropy (ΔSin) values were negative at all temperatures tested. In summary, the increase in ΔGin accompanied by decline in ΔSin and ΔHin values at elevated temperatures suggests that the enzyme is heat stable and thus, very suitable for the degradation of pectic substances in fruit effluents, food, and beverage products. [ABSTRACT FROM AUTHOR] |
