Efecto de la irradiación y el flujo de nutrientes sobre el contenido en polisacáridos ácidos en macroalgas cultivadas

The use of macroalgae as biofilters in "Integrated Multi-Trophic Aquaculture" IMTA systems has been, until now, primarily focused on its capacity for dissolved nutrients removal (N-NH4 plus and P-P043-), not in biomass composition, its potential market or added value as an additional organism generated in the production system. Even in cases in which macroalgae biofiltration efficiency is not high and low market value, algae production could be profitable, such as food or supplement for other high value species such as "Abalone" and other species of molluscs and echinoderms. The biomass produced in these systems, properly processed is being evaluated at different scales, also in applications such as production of agricultural biofertilizers, production of phycobiliproteins, phycocolloids (agar and carrageenan) and other polysaccharides, obtaining substances with antioxidant activity (polyphenols, pigments and amino acids like mycosporine - MAA's) and recently in the production of lipids-triglycerides as a source for biodiesel production (among other biofuels). In this work, the most significant results of the evaluated biomass are shown, inasmuch as biotechnological purposes refers, of a group of red algae (Hydropuntia cornea, Hypnea spinella, Halopithys incurva and Jania adhaerens) intensively cultivated under high concentrations of N-ammonium and P-phosphate in an IMITA system, fish (Sparus aurata) - algae. The biomass was produced under different irradiation conditions (natural 100 per cent PAR) and natural under greenhouse 80 per cent PAR plus 10 per cnet UVA plus 0 per cent UVB) and dynamic flow-nutrient was modified over time (high input vs limitation) to study the effect on the composition and accumulation of acid polysaccharides. Moreover, the dynamics followed by the species growing in monoculture (Hydropuntia cornea e Hypnea spinella) and species growing together, in co¬culture (Jania adhaerens and Halopithys incurva) were compared, to establish some type of relationship or association. The main producing species of acid polysaccharides were Hydropuntia cornea and Hypnea spinella (typical producing polysaccharide industrial level) while Halopithys incurva and Jania adhaerens showed minimum values indicating that their metabolism is more directed towards the synthesis of another type of secondary metabolites. A comparison between culture conditions and response accumulation-reduction of the substances evaluated of the biomass will be presented and discussed.