Mild One-Step Protein Recovery from Microalgae Cultivated in Swine Wastewater Using Natural Deep Eutectic...

Area of Science:

• Biotechnology
• Green Chemistry
• Wastewater Treatment

Background:

• Microalgae cultivation in photobioreactors treats wastewater and yields valuable biomass.
• Proteins are a key component of microalgae, making them a target for biotechnological applications.
• Developing efficient and sustainable protein extraction methods is crucial.

Purpose of the Study:

• To evaluate natural deep eutectic solvents (NADESs) in aqueous two-phase systems (ATPSs) for one-step protein extraction from microalgae.
• To compare the efficiency and selectivity of different NADES-based ATPSs.
• To identify optimal conditions for greener protein recovery.

Main Methods:

• Six ATPSs were prepared using two NADESs (betaine:levulinic acid and choline chloride:urea) and their components with phosphate salts.
• Protein recovery yield (PRY) and selectivity (R) were assessed at room temperature for varying extraction times.
• NADES-based ATPSs were characterized for their potential in protein recovery from microalgae in swine wastewater.

Main Results:

• The ATPS {betaine:levulinic acid + K3PO4 + H2O} demonstrated a PRY of 16.4% and high selectivity (R = 2.17 g·g-1) within 30 minutes.
• Proteins were primarily recovered in the NADES-rich phase, with minimal presence in the salt-rich phase.
• While betaine alone yielded the highest PRY (18.2% at 120 min), the betaine:levulinic acid ATPS offered a better balance of efficiency and time.

Conclusions:

• NADES-based ATPSs show significant potential as sustainable platforms for efficient protein recovery from microalgae.
• The betaine:levulinic acid ATPS provides an effective and greener alternative for protein extraction, especially at shorter process times.
• These systems are viable for recovering proteins from microalgae cultivated in nutrient-rich wastewater, contributing to circular economy principles.