In many bacteria, the production of virulence factors is controlled by quorum sensing (QS) and interfering with QS has been proposed as a new strategy to fight infections in aquaculture. Increasing attention is being paid to quorum quenching (QQ), the degradation of QS molecules by bacterial enzymes. The goal of the project is to isolate QS degrading organisms, construct mutants with high QQ activity, and evaluate the effect of QS degrading strains.