Wet extraction of metabolites from microalgae

Microalgae and cyanobacteria represent a promising plant bioresource for the production of metabolites of interest in achieving the sustainable development goals defined by the United Nations, in particular the development of safe and healthy food, the production of renewable energies and sustainable industrial production (Sustainable Development Goals 2, 7, 9, 12). These microorganisms produce, for example, proteins containing essential amino acids, polysaccharides with texturizing and antibacterial properties, lipids including certain antioxidants, pigments, terpenes and more. Several of these molecules also offer very interesting prospects as amphiphilic, emulsifying or foaming molecules, useful in detergents for example. All these properties make microalgae and cyanobacteria potential resources for many sectors, including nutraceuticals, health, animal feed and biofertilization, as well as green chemistry, biomaterials and biofuels.

Industrial-scale cultivation of microalgae and cyanobacteria is already mature for a number of strains, such as Arthrospira platensis (more commonly known as spirulina), Chlorella vulgaris and Tetraselmis chui, with direct applications in food and feed [CHV 4 030][CHV 4 032] . Today, research in the field of cultivation is focused, for example, on the control of metabolism in large-scale cultivation to improve the production of molecules of interest such as proteins, polysaccharides, lipids (triglycerides), pigments (carotenoids, phycobiliproteins), etc., and the intensification of production, as well as implementation in an industrial ecology context [CHV 4 036] .

Biorefining to extract value from the various fractions of microalgae after biomass harvesting is also a challenge, and has been the focus of research by numerous teams around the world for the past fifteen years....