Development of next-generation probiotics to counteract infectious diseases in oyster aquaculture

This project is a response to the European Commission’s initiative to improve the sustainability and competitiveness of aquaculture in Europe by addressing the challenge of diseases in oyster farming. Oyster production suffers significant losses due to infectious diseases, primarily Ostreid herpesvirus and Vibrio aestuarianus, resulting in high mortality rates. Hence, reducing mortalities is crucial to securing production.

Probiotics for aquaculture are gaining momentum as an alternative strategy to antibiotics to prevent and potentially treat pathogenic diseases. Probiotics are beneficial live bacteria that, when administered in adequate amounts and timing, confer a health benefit on the hosting aquatic animal and contribute directly or indirectly to protection against harmful pathogens. Suggested modes of action of probiotics against pathogens include the production of inhibitory compounds, competition for adhesion sites, disruption of quorum sensing, competition for chemicals or available energy, and enhancement of immune response. While probiotics have shown healthful benefits and applications in human and terrestrial veterinary science, their effect in aquaculture requires more exploration.

This project aims to isolate novel probiotics from oyster aquaculture for oyster aquaculture to counteract infectious diseases by adopting a step-by-step approach in vitro to select the candidate probiotics progressively. According to the European Food Safety Authority Regulations, the procedure will follow safety, physiological, functional and technological criteria. At the end of this procedure, the strains with the highest number of beneficial properties and without negative traits will be selected, and a microbial biobank will be compiled. Subsequently, in vivoexperiments will be applied to assess the host-microbe innocuousness, adaptability, suitability, functionality, and endurance of the processing technology.

Developing probiotics for oyster larvae could greatly benefit oyster farmers by reducing the loss in their larvae yields and improving their quality before locating them offshore. As much still needs to be explored, this research will increase the understanding and development of probiotic applications in aquaculture research.