Immobilization, biochemical, thermodynamic, and fruit juice clarification properties of lignocellulosic biomass–derived exo-polygalacturonase from Penicilliumpaxilli

• Published in: Biomass conversion and biorefinery 2023, Vol.13 (14), p.13181-13196
• Main Authors: Amin, Faiza, Asad, Syeda Anam, Nazli, Zill-i-Huma, Kalsoom, Umme, Bhatti, Haq Nawaz, Bilal, Muhammad
• Format: Article
• Language: English
• Subjects: Biotechnology; Energy; Enthalpy; Enzymes; Fruit juices; Gibbs free energy; Grapes; Immobilization; Juices; Lignocellulose; Manganese; Optimization; Original Article; Pectin; Polygalacturonase; Renewable and Green Energy; Substrates; Thermal stability
• ISSN: 2190-6815; 2190-6823
• DOI: 10.1007/s13399-022-02559-1

Exo-polygalacturonase was produced from a fungal strain Penicillium paxilli under solid-state fermentation (SSF) technique using wheat and rice bran (1:1) as a substrate. Production optimization data suggested that yeast extract, pectin, and manganese sulfate significantly enhanced the exo-polygalacturonase yield. This enzyme was partially purified using NH 4 (SO 4 ) 2 precipitation at 70% saturation level and characterized in terms of various parameters. The pH optima shifted from 3.5 to 6.5, while transition in temperature optimum was observed from 35 to 40 °C in case of immobilized enzyme. After immobilization at 70 °C, a 16% and 15% increase in values of half-life and enthalpy (Δ H *), respectively, and 2.25% decrease in Gibbs free energy (Δ G *) values were observed. K m value was observed to be 0.084 µmoles/mL/min with a 33% decline in V max value for immobilized exo-polygalacturonase. Immobilization showed 47% retention in bioactivity even at the 5th cycle of reuse. Results of different fruit juice treatment with exo-polygalacturonase showed that total phenolic and antioxidant contents of pomegranate and grapes juice were enhanced by 256% and 18%, respectively, while a 93% increase in clarification and 55% reduction of viscosity were observed in the case of grape and pineapple juices after enzymatic treatment. Finally, it can be concluded that this exo-polygalacturonase showed a good performance in the case of thermal stability and can be successfully implemented as an excellent candidate to be used in the fruit juice industry.