Integrated bio-refinery processes for valorization of Sargassum biomass from Mexican Caribbean Coast

Abstract

Since 2014, Mexican Caribbean coasts have experienced an atypical massive arrival of pelagic Sargassum that accumulated on the shores triggers economic losses, public health problems, and ecosystem damaging near the coastline. Mechanical harvesting has been implemented ending in landfills. Since Sargassum algae represent an abundant biomass in tropical regions of the world, it has shown potential as a feedstock to supply bioprocesses focused on obtaining high-value compounds and bioproducts. However, there is a lack of data on the biochemical composition of Sargassum biomass from Mexican Caribbean coasts to propose valorization pathways. In this sense we conducted a biochemical and elemental characterization of Sargassum biomass collected from Cozumel, Mexico, and evaluated how different factors such as Season, type of Sargassum and extraction method influences in the biochemical composition of the biomass. We also conducted a Soxhlet extraction of metabolites using three different solvents, in order to investigate the antimicrobial, antiparasitic and antioxidant capacity of Mexican Caribbean Sargassum. We found that the composition of Sargassum is influenced by season changes. Harvesting Sargassum directly from the shallow water make it more suitable for biomolecules recovery than dried Sargassum from the beach. Laccases are not suitable enzymes for Sargassum hydrolysis, and MAE had better extraction performance than EAE. We also found that Sargassum has an important antioxidant activity, and an antimicrobial effect using different solvent fractions. Finally, Sargassum present a great potential as a biosorbent of pollutants such as toxic metals in coastal ecosystems. In general, this thesis made an approach to Bio-refinery of Sargassum biomass from Mexican Caribbean coast using green technology to extract bioactive compounds, and make the most of resources that have a potential biotechnological application for biofuel, agriculture, cosmetic, nutraceutical and pharmaceutical industries.