This project targets an industrial proof-of-concept for the sustainable production of microbial protein from biogas. We will use a novel, standardised microbial consortium, containing a methane oxidizing bacterium and two heterotrophic microorganisms, for which a technical POC already exists. The resulting product is rich in proteins with high nutritional value, and contains carotenoids, with antioxidant and pigment properties. This microbial protein will replace conventional, unsustainable protein sources, e.g., meat products. As a first killer market, we will introduce the protein, after thorough characterization, into the pet food market as a sustainable alternative pet food for cats and dogs. Protein products will be tested in vitro for digestibility and in vivo for acceptability. Both the scale-up and the application tests will provide the necessary information for a financial plan and associated marketing strategy for the foreseen spin-off Carotein®.