The meta-transcriptome of the rainbow trout gut microbiome in relation to stress and diet (MetaBac)

• Applicant: Professorin Dr. Stéphanie Céline Hornburg
• Subject Area: Animal Breeding, Animal Nutrition, Animal Husbandry
• Term: from 2018 to 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 401653591

The bacterial gut community of fish, the so-called intestinal microbiome, interacts with the metabolism and the immune system of its host in various ways. However, an exact description of these interactions is yet to be done, especially for aquaculture species. Microbiome research in aquaculture has focused mainly on the structural composition of the bacterial community (who is there?) and hardly on their function (what are they doing?). In previous studies, it has been demonstrated that environmental condition, genetic origin, physiological changes, stress and especially feed ingredients affect the structural composition of the fish gut microbiome. The focus of this research project will be, therefore, to analyse the functional characteristics of the rainbow trout gut microbiome in relation to various feeding strategies and handling stress. Our own research on the influence of feed on the intestinal microbiome and previous studies on the effect of the bacterial community on stress resistance of fish form the basis for the hypothesis that the microbiome could establish a connection between nutrient supply and stress resistance. Successful fish farming is mainly based on optimal nutrient supply and a stress-free environment. Especially in commercial fish farms, chronic postural or handling stress has a strong effect on fish growth, despite optimal feeding, and thus, on production success. Since previous studies also suggest an influence of the genetic background on the composition of the microbiome, this factor is additionally considered by directly comparing trout from two different breeding lines in a specific experimental approach. The transcriptome data to be determined will, thus, not only enable a structural analysis of the microbial community in the fish gut (who is there?), but especially a functional characterization of the microbiome (what are they doing?). Thereby, this project will significantly contribute to the understanding about the structure and function of the intestinal microbiome in aquaculture species.

• DFG Programme: Research Grants