De Bruijn Group

The fish egg microbiome: functions and impact on emerging diseases.

Aquaculture is currently the fastest-growing animal food sector and will further increase to feed the growing human population. Along with this growth, aquaculture is suffering more and more from emerging diseases that threaten production yields. Due to the ban on chemical pesticides with toxic side-effects on environment and human health, there is an urgent need for new and sustainable measures to mitigate emerging fungal and oomycete aquaculture diseases.

Many studies have unequivocally shown that microbes play a pivotal role in protection of eukaryotes (humans, plants, insects) against diseases. New ‘omics’-based technologies have enabled the characterisation of the microbial communities (microbiome) in diverse ecosystems. To date, however, most microbiome studies only describe which microbes are present (or absent). For fish and especially fish eggs, microbiome studies are few. Fundamental insight into the mechanisms of how fish microbiota interact, and the effects on the fish pathogens and the fish immune response is limited.

Our aim is to disentangle the microbiome functioning by i) deciphering the molecular and biochemical activities of bacterial consortia on fish pathogens and ii) investigating the effect of the bacterial consortia on the fish immune response. This project will provide new insight into the functions and impact of the fish microbiome on emerging diseases.

Keywords: microbial ecology, species interactions, antimicrobial compounds, Saprolegnia, trout, zebrafish

Projects

• Protective microbial consortia
  An in-depth molecular and ecological understanding of the composition and dynamics of protective microbial communities associated with fish eggs is still lacking. In this project, fish egg-associated microbial communities will be constructed and test these ‘synthetic communities’ for activity against fish and fish egg pathogens, including Saprolegnia and ectoparasites. Furthermore, the interactions among the members in the bacterial community will be studied to elucidate the mechanisms and bioactive compounds involved in protection. Besides insights into how bacteria interact in microbial consortia, also the fish immune response to beneficial bacteria will be studied. In collaboration with Prof. dr. Geert Wiegertjes (WUR). Funding: TTW.

• Microbiomes of fish eggs
  The oomycete Saprolegnia is a relevant fish pathogen in aquaculture and current control measures are going to be banned in the near future. In commercial hatcheries, some egg batches get infected with Saprolegnia while others remain unaffected despite the fact that each of the batches contain eggs from the same broodstock, receive water from the same source and are treated similarly. This project aims to identify the microbes that are important for disease suppression by using metataxonomic microbiome analyses and key microbial taxa will be further characterized. Funding: ParaFishControl-Horizon 2020 (http://www.parafishcontrol.eu). See also the attached ParaFishControl newsletter and the project movie https://www.youtube.com/watch?v=9gjvZVUxh_Y&feature=youtu.be.

Current group-members

This group is associated with the Raaijmakers Group