natural Deep Eutectic solvents foR Microalgae bIorefinery in Cosmetic – DERMIC

This project combines in silico approaches for the prediction of solvent properties via the COSMO RS tool, with experimental measurements of the parameters of the generated solvents (viscosity, density, eutectic point), for the design and selection of NaDES. The process approach is carried out by screening classic eco-extraction processes (ultrasound, CPC) using prediction tools such as the RSM approach coupled with ANN analysis. Finally, a process innovation component has also been set up, drawing inspiration from industrial equipment from different fields to completely rethink the extractive approach using these new solvents.

A library of apolar or intermediate-polarity NaDES was compiled using an empirical approach, resulting in around 150 apolar or intermediate-polarity NaDES. The solubilization capacity of the target metabolites (palmitic acid, beta-carotene) was determined, along with preliminary physico-chemical characterization. The most relevant NaDES systems were then screened on the basis of preliminary solubility results. Fifteen NaDES were screened per strain, in different pre-treatment states. The phycoprotein extraction co-product, available for 2 strains, proved to be the richest in free fatty acids, which are our target apolar metabolites. It also emerged that, depending on the lipid profile of the strains and the structure of the microalgal walls, the best-performing NaDES were not identical, highlighting instead NaDES/pre-treated strain couples. With regard to phycoproteins, only 2 strains were involved. An exploratory screening approach identified glycerol-based NaDES as the most relevant. Ultrasonic extraction optimization using DoE and ANN approaches.

Preliminary sequential S/L extraction tests were carried out, and quickly highlighted the critical impact of the order of operations. These trials led to the development of a solid/liquid/liquid extraction process using pairs of 2 NaDES or NaDES/water. This process, successfully applied to the 2 phycoprotein-enriched strains, enabled polar fractions to be prepared and purified in a single step, while yielding apolar fractions significantly enriched in free fatty acids and pigments. The NaDES from the library are currently being studied in silico using the COSMO-RS approach, to establish their phase diagram and elucidate the precise eutectic point. A simplified a priori selection approach based on easily accessible “sigma” descriptors has thus been developed, notably using thermodynamic data on target systems and metabolites. This “sigma” screening combining profile, potential and sigma surface allows a priori selection of components likely to form a eutectic mixture, while adapting their selectivity to the target metabolites. This approach also makes it possible to simulate a potential eutectic point, considerably reducing the resource consumption of the design and screening stage.

This in silico approach feeds into the Smart selection strategy developed in the laboratory, setting out material specifications for the design of eutectic solvents that can be used directly as cosmetic ingredients. The introduction of these eutectic solvents and extracts in eutectic media in gel form has had a positive impact on the behavior (viscosity booster) and sensory properties of the finished products.

The processes developed in the course of this project are currently being studied for transfer to the industrial partner in biomass and co-products.

An innovative process has been the subject of a Soleau envelope and is currently undergoing a maturation procedure with a view to the creation of a start-up.

The Solide/liquid/liquid process is currently being deployed in other biomass and application fields.

The Smart selection strategy is currently being deployed in the healthcare sector, with applications in infectiology. This has led to the submission of a project under the PEPR biotherapy program and the award of a thesis grant under the PIA Loire Val Health program.

Peer-reviewed publication
1. L. Wils, S. Hilali and L. Boudesocque-Delaye, Biomass valorization using Natural Deep Eutectic Solvents: what’s new in France? Molecules, 2021, 26, 6556. doi.org/10.3390/molecules26216556
2. S. Hilali, L. Wils, A. Chevalley, B. Clément-Larosière, L. Boudesocque-Delaye, Glycerol-based NaDES as green solvents for ultrasound-assisted extraction of phycocyanin from Arthrospira platensis-RSM optimization and ANN modeling, Biomass Conversion and Biorefinery, 2022, doi.org/10.1007/s13399-021-02263-6
3. S. Elderderi, L. Wils, C. Leman-Loubière, H.J. Byrne, I. Chourpa, C. Enguehard-Gueiffier, E. Munnier, AA Elbashir, L. Boudesocque-Delaye, F. Bonnier. In Situ Water Quantification in Natural Deep Eutectic Solvents Using Portable Raman Spectroscopy. Molecules 2021, 26, 5488. doi.org/10.3390/molecules26185488
4. S. Elderderi, L. Wils, C. Leman-Loubière, S.Henry, H. J. Byrne, I. Chourpa, E. Munnier, A. A. Elbashir, L. Boudesocque-Delaye, F. Bonnier Comparison of Raman and ATR-IR for water quantification in NaDES Analytical Bioanalytical Chemistry, 2021, 413(19), 4785–4799 doi.org/10.1007/s00216-021-03432-2
5. L. Wils, C. Leman-Loubière, N. Bellin, B. Clément-Larosière, M. Pinault, S. Chevalier, C. Enguehard-Gueiffier, C. Bodet, Leslie Boudesocque-Delaye Natural Deep Eutectic Solvent formulations for spirulina: preparation, intensification, and skin impact. Algal Research Special Issue on Advanced Technologies 2021, 56, 102317, doi.org/10.1016/j.algal.2021.102317

Oral presentation
1. L Boudesocque-Delaye, Natural deep eutectic solvents for microalgae biorefinery: Spirulina as a case study, Vitrual Meeting of AFERP, July 2021
2. L. Wils, S. Hilali, S. Elderli, M. Yagmur, C. Leman-Loubière, B. Clément-Larosière, F. Bonnier, L. Boudesocque-Delaye Natural deep eutectic solvents for microalgae biorefinery: Spirulina as case of study, 2nd International Meeting on Deep Eutectic System, Lisbon (Portugal), 15-17 juin 2021
3. S. Elderderi, C. Leman-Loubière, L. Wils, S. Henry, D. Bertrand, H. J. Byrne, I. Chourpa, C. Enguehard-Gueiffier, E. Munnier, A. A. Elbashir, L. Boudesocque-Delaye, F. Bonnier, ATR-IR spectroscopy for rapid quantification of water content in deep eutectic solvents 2nd International Meeting on Deep Eutectic System, Lisbon (Portugal), 15-17 juin 2021
4. I. M. Ardeza, L. Boudesocque-Delaye, L. Wils, A. Despres, F. Bonnier, X Perse, C. Bodet, I. Chourpa, E Munnier Natural deep eutectic solvents: the future of natural cosmetic formulation? 2nd International Meeting on Deep Eutectic System, Lisbon (Portugal), 15-17 juin 2021
5. L. Wils, S. Hilali, M.Yagmur, B. Clément-Larosière, L. Boudesocque-Delaye, NaDES for microalgae biorefinery: biomass pre-treatment and comparison with bio-sourced solvents, 2nd International Meeting on Deep Eutectic System, Lisbon (Portugal), 15-17 juin 2021

General public conference
L. Boudesocque-Delaye, F. Bonnier, E. Munnier, Les cosmétiques passent au vert, Conférence grand public Fête de la Science 2021, 6 oct 2021 www.fetedelascience.fr/les-cosmetiques-passent-au-vert

The use of microalgae have focused the interest of cosmetic industry for some years now, as renewable resources of various biomolecules. Natural Deep Eutectic Solvents (NaDES) represent an exciting opportunity for microalgae eco-extraction. NaDES are considered as a new generation of green ionic liquids. Their main interest lies in their renewability and biodegradability as they are prepared by mixing vegetal cellular constituents. Their composition makes also NaDES truly biocompatible allowing to avoid solvent removal step. Numerous references described NaDES as solvent for solid/liquid extraction of plants, mostly focusing on polyphenols and flavonoids but only one reference deals with microalgae extraction. This project propose a biorefinery approach using NaDES to produce several cosmetic high added-value ingredients from microalgae biomass. Cosmetic dedicated NaDES will be designed, characterized and applied to several microalgae to propose a sustainable upgrading scheme.