In a frame of circular economy, the Mysushi project investigated the use of crude glycerol, a primary by-product of biodiesel production, as a low-priced nutrient source for heterotrophic cultivation of the fungus-like protist Schizochytrium limacinum SR21 strain. The whole biomass of this oleaginous microorganism, rich in docosahexaenoic (DHA) and high-quality proteins, was then paired with a vegetable oil source and used to replace fish oil in farmed European sea bass (Dicentrarchus labrax) feeds. 

Values of health-related lipid indexes, such as atherogenicity index, thrombogenicity index, and flesh lipid quality as well as omega-6/omega-3 and polyunsaturated/saturated fatty acids (PUFAs/SFAs) ratios confirmed the high nutritional value of sea bass fillet, thus representing a healthy product for human consumption.  

Fish transcriptomics and gut microbiota were also studied in the project. 

Overall, Mysushi project added new know-how concerning the use of oleaginous microbial biomass as a valid alternative to fish oil for fish feeds.