Functionalised ceramic spawning tiles with probiotic Pseudoalteromonas biofilms designed for clownfish aquaculture

To prevent marine fish egg clutches of substrate spawners from bacterial and fungal infestation, functionalised ceramic spawning tiles with probiotic bacterial biofilms were designed for clownfish aquaculture in this study. Therefore, mechanically stable ceramic spawning tiles made of alumina were fabricated with convenient substrate properties for Pseudoalteromonas immobilisation, i.e., hydrophobic matrix and hydrophilic surface properties. An effective biofilm formation was achieved by equilibration of these ceramic tiles in marine liquid medium containing 1wt% starch and subsequent inoculation with two different Pseudoalteromonas strains. Biofilm formation was confirmed qualitatively by scanning electron microscopy (SEM) and quantitatively by photometrical measurements according to Safranin O staining. Furthermore, antagonistic effects originating from Pseudoalteromonas biofilms against Paecilomyces lilacinus were detected by SEM, which are possibly due to bioactive molecules. Consequently, these innovative microbiologically conditioned ceramic spawning tiles are promising candidates to prevent fish egg clutches from pathogenic infestation, which leads to an improved aquaculture of substrate spawners such as clownfishes. •Porous ceramic tiles with hydrophilic surface functionalisation served as promising substrates for bacterial immobilisations.•Pseudoalteromonas sp. showing antagonistic effects against both bacterial and fungal (clown)fish pathogens were isolated from aquaria samples.•Pseudoalteromonas sp. biofilm with antagonistic activity for weeks were formed in optimised medium containing starch.•Water samples showed fungi-static and bateriostatic effects against fish pathogens due to bacterial wash out from probiotic ceramic tiles.