Macroalgal biomass intensive tank production as affected by co-culture and nutrient dynamic

Abstract

Red and green macroalgae with biotechnological potential were intensively co-cultivated in 90 L tanks to test, as a new experimental approach, if biomass production and biofiltering capacities in nutrient enriched effluents were positive or negatively affected by different species growing in the same tank at the same time (co-culture), when compared to standard monoalgal cultures. Tank co-cultures of Jania adhaerens with Halopithys incurva, Grateloupia turuturu with Ulva rigida, Grateloupia imbricata with Hypnea musciformis and Hydropuntia cornea, were assayed and data compared to monoalgal cultures of H. cornea, Hypnea spinella and U. rigida.

Nutrients, N-NH4+ and P-PO34−, were continuously provided during 4 weeks previous to a 2 weeks period with running seawater (nutrients deprivation). Under the combined effects of light, temperature and nutrients flow dynamic, algal yields and growth rates, ammonium and phosphate biofiltration capacities, pigments content and chlorophyll fluorescence parameters, as physiological stress indicators, were determined. Biomass obtained from the different treatments was mainly evaluated for acid polysaccharides content and antioxidant activity. Results on the combined effect of the different assayed conditions reveal how algae species co-cultivation might be an interesting approach for nutrients removal in integrated multi-trophic aquaculture units (IMTA), as well as the biomass produced might be treated to obtain high-value metabolites under the biorefinery concept.