Broad-spectrum light-responsive deep eutectic solvents for ambient microalgae disintegration with intact fractions

Area of Science:

• Biomass Valorization
• Green Chemistry
• Biorefining Technologies

Background:

• Integrating microalgae valorization is crucial for sustainable biorefineries.
• A key challenge is balancing microalgae cell wall disruption with biomolecular integrity.
• Existing methods often require high energy input or compromise component quality.

Purpose of the Study:

• To develop a mild, light-responsive pretreatment platform for microalgae.
• To reconcile the trade-off between disintegration efficiency and biomolecular preservation.
• To create a cost-effective and energy-efficient biorefining strategy.

Main Methods:

• A ternary deep eutectic solvent (DES) system comprising Fe3+, α-hydroxycarboxylic acid, and water was developed.
• The system utilized ambient light irradiation for mild, short-duration (2h) pretreatment.
• Mechanistic insights were gained through spectroscopy and theoretical calculations, alongside life cycle cost analysis.

Main Results:

• The light-responsive DES system achieved 91.6% lipid extraction efficiency, preserving fatty acids.
• High-recovery protein (80.4%) and digestible carbohydrates were retained.
• Extracted lipids and synthesized microbial lipids were converted to ASTM D6751-compliant biodiesel; the DES was stable over six recycles.

Conclusions:

• The dual-amplification strategy effectively addressed microalgae cell wall recalcitrance and photo-Fenton process limitations.
• This ambient-light-driven method enables efficient microalgae disintegration while preserving component integrity.
• The developed technology offers a scalable and sustainable approach for biomass biorefining.