2026-05-20T19:28:22Zhttps://uvadoc.uva.es/oai/request

oai:uvadoc.uva.es:10324/824042026-03-25T09:31:15Zcom_10324_1185com_10324_931com_10324_894col_10324_1346

Mild one-step protein recovery from microalgae cultivated in swine wastewater using natural deep eutectic solvent-based aqueous biphasic systems Moldes Plaza, David Vega Alegre, María del Sol Bolado Rodríguez, Silvia Fernández Requejo, Patricia Separation (Technology) Protein extraction Green solvents Biomass valorization Microalgae biomass Aqueous two-phase system (ATPS), Natural deep eutectic solvents (NADES), Protein recovery, Green extraction, Microalgae biomass, Biomass Valorization 3303.04 Separación Química 2301.02 Análisis Bioquímico Producción Científica Photobioreactor-based microalgae cultivation offers an integrated approach for nutrient-rich wastewater treatment while producing valuable biomass. One of the main microalgae components is proteins, making them a biotechnological target. In this work, to develop efficient and greener extraction methodologies, aqueous two-phase systems (ATPSs) based on natural deep eutectic solvents (NADESs) were evaluated for one-step protein extraction from microalgae cultivated in swine wastewater. Six ATPSs combining two NADES—betaine:levulinic acid (Bet:2LA) and choline chloride:urea (ChCl:2Urea)—and their individual components (Bet or ChCl) with phosphate salts were compared. Systems {NADES + K3PO4 + water} were characterized and reported for the first time. Protein recovery yield (PRY) and selectivity (protein-to-carbohydrate mass ratio, R) were assessed for three extraction times and at room temperature. The ATPS {Bet:2LA + K3PO4 + H2O} achieved a PRY of 16.4% and remarkable selectivity after 30 min (R = 2.17 g/g), with proteins concentrated in the NADES-rich phase, and negligible recovery in the salt-rich phase. Although the maximum PRY (18.2% at 120 min) was achieved with the precursor betaine, the ATPS with Bet:2LA at 30 min offered an optimal balance between efficiency and process time. With a water content of up to 50%, these systems underscore the potential of NADES-based ATPSs as sustainable platforms for protein recovery. This work was supported by Grant PID2023-153356OB-I00, funded by MICIU/ AEI/10.13039/501100011033 and by ERDF/EU and by Consejería de Educación of the regional government of Castilla y Leon and ERDF/EU (VA068G24, UIC 338 and CLU-2025-2-06).David Moldes would like to thank the Ministry of Science, Innovation and Universities for his doctorate scholarship (FPU20/02086) 2026-01-30T11:37:02Z 2026-01-30T11:37:02Z 2026 info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion Molecules, 2026, 31, 483 1420-3049 https://uvadoc.uva.es/handle/10324/82404 10.3390/molecules31030483 1 483 18 Molecules 31 eng https://www.mdpi.com/1420-3049/31/3/483 Attribution-NonCommercial-NoDerivatives 4.0 Internacional info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by-nc-nd/4.0/ application/pdf MDPI https://uvadoc.uva.es/bitstream/10324/82404/5/2026_molecules_ATPS-protein.pdf.jpg Hispana TEXT http://creativecommons.org/licenses/by-nc-nd/4.0/ UVaDOC. Repositorio Documental de la Universidad de Valladolid https://uvadoc.uva.es/handle/10324/82404