The potential of Ulva diversity in southern Portugal for a sustainable food and feed industry

The food and feed industry surpass their sustainable boundaries and global food security is one of society's biggest challenges today. Macroalgae of the genus Ulva have been identified as a suitable candidate for cultivation, with various applications within the food and feed industry. This work discusses the sustainability performance of Ulva cultivation and identifies the potential of Ulva species in southern Portugal for their use in the food and feed industry. It was tested, which species are available in different coastal and lagoon habitats and whether species identity or environmental conditions have a stronger effect on the seaweed’s protein content and fatty acid profile, to find out, whether the selection of one Ulva species is favorable over another for cultivation. Ulva species were collected at coastal and lagoon locations in southern Portugal and genetically identified, using the tufA gene sequences. Ulva rigida, Ulva flexuosa, Ulva fasciata, Ulva australis and Ulva compressa were identified as potential cultivation candidates. U. australis has not previously been reported in southern Portugal. Protein content in U. rigida sampled in coastal locations was higher (p < 0.01) compared to lagoon locations, but not different among species within the Ria Formosa (p = 0.363). Fatty acid profiles were not different across locations (p = 0.739). However, U. compressa had a higher PUFA content than U. rigida and U. fasciata within the Ria Formosa (p = 0.0245). Results suggest that U. compressa might be more a more suitable Ulva candidate for PUFA production and that protein content in seaweeds may be more susceptible to environmental conditions. In southern Portugal, Ulva is still an underexploited resource but has the potential to be part of the solution to overcome food security challenges in the future.