Activities carried out under the Horizon 2020 CIRCLES project “Controlling mIcRobiomes CircuLations for bEtter food Systems.” During the project activities, marine microbial strains with high enzymatic activities were isolated, identified and studied. The strains were characterized and their production on an industrial scale was studied for inclusion in the formulation of bioactivators for use in fish farms. The goal is to degrade the organic component (feed residues and excreta) present in the seabed affected by sea cage installations so as to make intensive fish farming more sustainable.