Preparation of Immobilized Lipase Based on Plant-derived Biomass and Catalytic Ability Evaluation

Abstract

An immobilized enzyme carrier was synthesized by pretreating plant-derived biomass with hydrochloric acid followed by oxidation with potassium permanganate. The biomass-based immobilized lipase was prepared by adsorbing lipase, an industrial biocatalyst, onto the immobilized enzyme carrier. XPS detected a nitrogen atom peak (399.9 ∼ 400.0 eV) derived from amino acids, confirming the immobilization of lipase. The adsorption capacity of immobilized lipase varied among different biomass sources, with the highest adsorption observed on rice (112.7 mg g⁻¹), followed by kenaf (107.1 mg g⁻¹), bamboo (84.1 mg g⁻¹), cedar (61.5 mg g⁻¹), and beech (29.1 mg g⁻¹). Herbaceous biomass exhibited higher lipase adsorption compared to woody biomass. In terms of catalytic activity, immobilized lipase exhibited the highest activity with cedar (61.3 units g⁻¹), followed by bamboo (21.4 units g⁻¹), beech (20.1 units g⁻¹), rice (14.8 units g⁻¹), and kenaf (14.0 units g⁻¹). Woody biomass demonstrated higher lipase activity than herbaceous biomass. The adsorption amount of lipase correlated with the cellulose content of the biomass, whereas the catalytic activity was influenced by the lignin content, which maintains the higher-order structure of the biomass. Based on these results, the cedar-immobilized lipase having the highest lipase activity was selected for the esterification reaction. When added to monocarboxylic acid and ethanol, the immobilized lipase facilitated the synthesis of esters and functioned as an effective catalyst.