PROMISEANG is a 48-month project that aims to develop novel alternative proteins from marine underexploited sources (marineinvertebrate and macroalgae discards and industrial biowastes) through biomass fermentation (solid-state and submerge processes),generating new microbial protein biomass, meeting market requirements for food, feed, and non-food (biomedicine, pharma andcosmetic) bio-based applications. A technically and economically viable biorefinery for microbial-based protein production will bedemonstrated during the project, enabling higher production yields, reduced production periods, minimized environmental impacts,diminish the imports, and reduced production costs for proteins. PROMISEANG contributes to CBE JU with a translational,multidisciplinary and multi-actor approach, including cooperation between industries and academia across EU, to achieve a greenerbio-based Europe. Following a zero-waste approach, PROMISEANG will also recover and biosynthesize interesting non-protein biocompounds and molecules (i.e., polysaccharides, lipids, polyphenols, PHA, etc.) for further use in food, feed and non-food applications.Research on novel protein streams from sustainable alternative sources will contribute to increase the protein availability in the EU, andreduce the actual dependency on imports. In short, PROMISEANG will upcycle of marine food wastes (WP2), apply innovative andsustainable technologies (incl. biotechnology, biochemistry, microbial fermentations, digital tools and machine learning, WP3), validatethe nutritious, safety and bioactivities of protein products (WP4), valorise fermentation side streams through nanotechnology (WP5)and design, development and validation of food, feed and non-food products in relevant environments (WP6) including improvement ofenvironmental, economic and social aspects, and production-efficiency performances (WP7), and strong communication, disseminationand exploitation plans (WP8).