European aquaculture is facing major challenges: external competition and consumer demands in terms of quality, environmental standards and competitive prices. Feed is one of the main costs of a fish farm, and typically represents 20-50% of the operating cost. However, most commercial fish farms apply non-optimised feeding regimes. Feeding strategies have strong interactions with optimised nutrition, allowing for optimal growth and health status of the fish, and minimal environmental impact. Amino acids (AA) in the diet are particularly important, and their requirements are altered in situations of environmental stress or pathology. The central objective of the ALISSA project is to develop formulations for a diet that promotes optimal nutritional and immune status, and within parameters of economic and environmental sustainability, in aquaculture fish. In more specific terms, the aim is to launch a highly innovative product on the market at the end of the project, as well as two unique services with high added value: 1) A range of supplements for fish feed, which will allow current feeds to be fortified with AA, and which will enable optimum performance and better resistance to pathogens, especially under stressful conditions, as well as recovery after infection. 2) An improved computer application to simulate the performance, biochemical composition and environmental impacts of fish fed different formulations at different temperatures.3) A service to assess the nutritional and immune status of fish in aquaculture, based on molecular biomarkers and depending on their diet.The participation in this project of two companies and seven entities from the SCTN, and collaboration with potential distribution partners and customers, strengthen the potential impact of this project on the European market.