Microalgae are promising microorganisms that can play a key role in bio-based economy, since they may serve as a continuous and reliable source of safe natural products, including pigments, polyunsaturated fatty acids (PUFA) and proteins of industrial interest. To date, microalgae production is currently limited to a few small industries, mainly for feed, nutrition and cosmetic sectors. Obtaining an economic and sustainable method to increase the production of commercial products from microalgae, still remains a challenge. In this scenario, a new biorefinery process is urgently needed to fully exploit microalgae. In this work, a cascade approach was designed to optimize the recovery of high valuable bioproducts starting from the wet biomass of Galdiera sulphuraria, a unicellular thermo-acidophilic red alga, capable of accumulating several bioactive compounds. Extractions were performed in three steps, coupling a conventional high pressure procedure to recover phycocyanin with a pressurized liquid extraction (PLE) for carotenoids and supercritical carbon dioxide (scCO2) extraction for lipids. These innovative, green and cost-effective procedures are able to improve the yields without affecting the quality of compounds avoiding the use of organic solvents and the drying processes.

Authors thank projects ABACUS (Algae for a Biomass Applied to the production of added value compoundS, grant agreement No 745668, funded by the Bio Based Industries Joint Undertaking under the European Union’s Horizon 2020 research and innovation programme) and AGL2017- 89417-R (MINECO, Spain) for financial support. M.B. acknowledges MINECO for a “Juan de La Cierva-Formación” postdoctoral grant FJCI-2016-30902.

Resumen del trabajo presentado a la IX Reunión de Expertos en Tecnologías de Fluidos Comprimidos (Flucomp), celebrada en el Campus UAM Cantoblanco (Madrid) del 13 al 15 junio 2018.

Peer reviewed