Probiotics have been established as potential tools to improve host health and environmental quality in aquaculture. For example,Shewanella putrefaciens Pdp11 (SpPdp11), a strain described as a probiotic for use in aquaculture (reviewedby Cámara et al. 2020). Despite the proven health benefits of probiotics, recent evidence suggests that bacterial viability is not necessary to attain effects. Thus, postbiotics have emerged as potential opportunities in the field of functional foods. The International Scientific Association for Probiotics and Prebiotics (ISAPP) convened a panel that defined postbiotics as a “preparation of inanimate microorganisms and/or their components that confer a health benefit to the host”.
The present work evaluates the potential postbiotic, as extracellular products (ECPs), of SpPdp11 grown undern different cultivation conditions. These included different culture media composed of a blend of microalgae, to observe a possible synergistic effect. The ECPs obtained were evaluated for their cytotoxicity against different fish cell lines, enzymatic and antibacterial activity, and their effect on biofilm formation by several fish pathogens