The impact of rearing environment on the development of gut microbiota in tilapia larvae

Abstract

This study explores the effect of rearing environment on water bacterial communities (BC) and the association with those present in the gut of Nile tilapia larvae (Oreochromis niloticus, Linnaeus) grown in either recirculating or active suspension systems. 454 pyrosequencing of PCR-amplified 16S rRNA gene fragments was applied to characterize the composition of water, feed and gut bacteria communities. Observed changes in water BC over time and differences in water BCs between systems were highly correlated with corresponding water physico-chemical properties. Differences in gut bacterial communities during larval development were correlated with differences in water communities between systems. The correlation of feed BC with those in the gut was minor compared to that between gut and water, reflected by the fact that 4 to 43 times more OTUs were shared between water and gut than between gut and feed BC. Shared OTUs between water and gut suggest a successful transfer of microorganisms from water into the gut, and give insight about the niche and ecological adaptability of water microorganisms inside the gut. These findings suggest that steering of gut microbial communities could be possible through water microbial management derived by the design and functionality of the rearing system.

Dietary probiotic supplementation improves growth and the intestinal morphology of Nile tilapia

“…Several management aspects may explain the lack of effects on FCR, such as lower water temperature and dietary protein level, the feeding frequency and the incorporation method of the probiotic. However, different hosts and rearing conditions, with their particular water and gut microbiota (Giatsis et al, 2015), may be sufficient for some unpredictability of the results. In a previous study in rainbow trout, the authors observed a decrease in VFI in fish-fed probiotics when compared with the control group (Ramos et al, 2015).…”

Analysis of the Gut Microbiome of Nile Tilapia Oreochromis Niloticus L. Fed Diets Supplemented with Previda® and Saponin

“…Recently, several studies have looked at what factors shape and modulate the development of the tilapia gut microbiome (Giatsis et al, 2015, Giatsis et al, 2014. During early ontogenetic stages, while the gut is not fully developed, the effects of environmental factors such as water physicochemical parameters are stronger.…”

Microbial interactions in the fish gut

“…Bakke et al (2013) demonstrated that the gut microbiota of cod larvae is more strongly influenced by microbiota present in the water rather than by the microbiota associated with feed (Bakke et al, 2013). In a previous study, we confirmed a high and consistent correlation between water and gut microbiota of tilapia larvae whereas less than 1% of all OTUs was shared between gut and feed (Giatsis et al, 2015). However, our present results show that bacteria associated to the diet lead to alterations in gut microbiota and that these changes are more pronounced in the sludge-based diets rather than in the control.…”

“…However, our present results show that bacteria associated to the diet lead to alterations in gut microbiota and that these changes are more pronounced in the sludge-based diets rather than in the control. Contrarily to previous studies (Bakke et al, 2013;Giatsis et al, 2015), gut shared a much higher number of OTUs with the feed than with the water. However, despite marked…”

“…In a recent study, Giatsis et al (2015) showed that feed microbiota had a very low impact on gut microbial communities. However, in that study a commercial pelleted feed was used.…”