Σύσταση, δομή και οικοφυσιολογικός ρόλος μικροοργανισμικών κοινοτήτων στον πεπτικό σωλήνα εκτρεφόμενων ιχθύων

• Published in: Proceedings of the Workshop on Computational Methods for Endangered Languages
• Main Authors: Nikouli, Eleni, Νικούλη, Ελένη
• Format: Doctoral or Postdoctoral Thesis
• Language: Greek
• Published: University of Thessaly (UTH) 2019
• Subjects: Sparus aurata; Dicentrarchus labrax; Diplodus puntazzo; Pagrus pagrus; Argyrosomous regius; Salmo salar; Βακτήρια; 16S rRNA; Πεπτικός σωλήνας; Εκτρεφόμενοι ιχθύες; Νυμφική εκτροφή; Εντερομικροβίωμα; Bacteria; Gut; Larviculture; Gut bacteria; Γεωπονικές Επιστήμες και Κτηνιατρική; Άλλες Γεωπονικές Επιστήμες; Agricultural and Veterinary Sciences; Other Agricultural Sciences
• Online Access: http://hdl.handle.net/10442/hedi/45621; https://doi.org/10.12681/eadd/45621

Studies have shown that host, diet and habitat can affect fish gut bacterial diversity, but even under the same environmental conditions, significant differences may occur. Up-to-date studies on fish bacterial symbionts are related to the effect of diet on the structure of these bacterial communities. This thesis studied for the first time the autochthonous gut bacterial diversity of Sparus aurata and Dicentrarchus labrax individuals originating from five distantly located aquaculture installations in Greece, in order to determine the impact of geographic location and to reveal their core gut microbiota.Moreover, we assessed whether five fish (Sparus aurata, Dicentrarchus labrax, Diplodus puntazzo, Pagrus pagrus, Argyrosomous regius) species cultured on the same site and fed with isoenergetic and isoproteic diets differ in their gut bacterial communities. Finally, we also investigated the host-associated bacterial succession during the early embryonic stages and first feeding in farmed Sparus aurata and Salmo salar populations.We analyzed the 16S rRNA gene diversity of Bacteria, targeting the V3-V4 region by using next generation sequencing techniques (454 pyrosequencing, illumina). Data analyses resulted in no significant geographic impact in the gut bacterial communities within the two allopatric host species (S. aurata, D. labrax), while strong similarities between them were also present. Our survey revealed the existence of a core gut microbiota within and between them independent of diet and geographic location consisting of the Delftia, Pseudomonas, Pelomonas, Propionibacterium, and Atopostipes genera.Results also revealed that the OTUs richness between the five sympatric host species (S. aurata, D. labrax, D. puntazzo, P. pagrus, A. regius) did not vary significant, but only 4% of the found OTUs belong to the core gut microbiota, indicating selective pressure within the gut, favoring the establishment and development of specific bacterial species in the gastrointestinal system in each of the five fish ...