Fungal β-1,3-Glucanases: Characterization and Immobilization for Continuous Application in Winemaking

Abstract

This work presents an innovative continuous biocatalytic system based on immobilized β-1,3-glucanase for white wine clarification. First, two β-glucanases from fungal sources Trichoderma harzianum and Aspergillus niger were comparatively characterized for optimal temperature and pH. The highest catalytic activity was at 50°C and pH 6.0 for both enzymes. Afterwards, the Trichoderma-derived β-glucanase was selected for covalent immobilization due to its higher catalytic efficiency and substrate affinity at low temperature and acidic pH. The immobilized enzyme exhibited enhanced tolerance to temperature and pH variations and retained operational stability over repeated use cycles. The immobilized biocatalyst was then applied in a fluidized-bed reactor (FBR) for the treatment of model white wine, and the maximum product release rate was achieved at a flow rate of 560 mL/min (corresponding to a τ of 0.54 min and a Sv of 1.87 min⁻¹) using 5 g of immobilized biocatalyst. Under these optimal conditions, the continuous treatment of real white wine in FBR resulted in the effective degradation of β-glucans achieving up to ∼75%–80% decrease within 24–48 h. Thus, demonstrating the use of the immobilized food-grade Trichoderma-derived β-glucanase in the FBR is a very promising method for continuous enzymatic clarification of wine.