Acceleration of lactose hydrolysis using beta-galactosidase and deep eutectic solvents

Area of Science:

• Green Chemistry
• Biocatalysis
• Materials Science

Background:

• Deep eutectic solvents (DES) offer tunable properties for various applications.
• Enzyme-catalyzed reactions can be limited by stability and efficiency.
• Novel DES are needed to improve biocatalytic processes.

Purpose of the Study:

• To synthesize and characterize new DES based on choline levulinate.
• To evaluate the physicochemical properties of these DES.
• To assess their performance as additives in enzymatic reactions.

Main Methods:

• Synthesis of DES using choline levulinate and hydrogen bond donors.
• Characterization via 1H NMR, FT-IR, Thermogravimetric Analysis (TG), and Differential Scanning Calorimetry (DSC).
• Measurement of physicochemical properties: density, viscosity, conductivity, and thermal stability.

Main Results:

• Prepared DES exhibited low viscosity (0.1-0.8 Pa·s at 40°C) and high thermal stability (>150°C).
• Densities ranged from 1.1-1.17 g cm⁻³.
• The DES stabilized enzymes and positively influenced their activity.

Conclusions:

• The novel DES series demonstrates significant potential for enhancing enzyme properties.
• A specific DES mixture (choline levulinate: ethylene glycol) tripled lactose hydrolysis yield using β-galactosidase.
• These findings highlight the relevance of designed DES for efficient substrate conversion in food processing.