Modulation of Intestinal Microbiota in Solea senegalensis Fed Low Dietary Level of Ulva ohnoi

Abstract

Gastrointestinal (GI) microbiota has a relevant role in animal nutrition, modulation of the immune system and protection against pathogen invasion. Interest in algae as source of nutrients and functional ingredients for aquafeeds is increasing in order to substitute conventional feedstuffs by more sustainable resources. The diet is an important factor in the modulation of the microbiota composition, and functional ingredients have been proposed to shape the microbiota and contribute benefits to the host. However, fish microbiome research is still limited compared to other hosts. Solea senegalensis is a flat fish with high potential for aquaculture in South Europe. In this study, a characterization of the microbiome of S. senegalensis (GI) tract and the effects of feeding Ulva ohnoi supplemented diet has been carried out. Differences in the composition of the microbiota of anterior and posterior sections of S. senegalensis GI tract have been observed, Pseudomonas being more abundant in the anterior sections and Mycoplasmataceae the dominant taxa in the posterior GI tract sections. In addition, modulation of the GI microbiota of juvenile Senegalese sole fed for 45 days a diet containing low percentage of U. ohnoi has been observed in the present study. Microbiota of the anterior regions of the intestinal tract was mainly modulated, with higher abundance of Vibrio spp. in the GI tract of fish fed dietary U. ohnoi.

Understanding pseudo-albinism in sole (Solea senegalensis): a transcriptomics and metagenomics approach

“…Divergence in the main identified bacterial genera between the previous and present study may derive from the approach and sample type as the previous study analysed bacteria pre-selected by culture methods from adult sole whole gut 58 while the present study used culture-independent 16 S rRNA gene sequencing for the juvenile anterior gut. In a recent 16 S rRNA-seq study Mycoplasma was also identified as one of the main genera detected in the Senegalese sole gut 60 , although in older sole from the same origin as those in the present study Mycoplasma were much less abundant 66 . Previous studies have indicated that age, diet, season and gut region can modify the fish gut microbiome and sample variation is a limiting factor for inter-study comparisons.…”

“…schophthalmi and V . ichthyoenteri are reported to be abundant in healthy reared flatfish, although some strains have been reported to be opportunistic pathogens in other flatfish species 53,57–60 . In Senegalese sole under normal or intensive aquaculture it appears that V .…”

“…Mycoplasma are small bacteria devoid of a cell wall, inhabiting mucous surfaces of humans or fish and are generally considered non-cultivable 61,62 . Recent culture-independent studies indicate that Mycoplasma may also be components of the healthy gut microbiota of a variety of fish species, with particular abundance in the gut of omnivorous or carnivorous species as is the case of Senegalese sole 53,60,63,64 . Although some species (e.g.…”

“…muscle thickness) that presumably influenced the composition of the colonizing microbiota in the gut. Future studies will be required to investigate physical, chemical and functional differences in the pseudo-albino gut compared to the pigmented sole, since specialization of the gut microbiome is likely to be influenced by its internal characteristics and for instance the growth of both Vibrio and Mycoplasma is highly influenced by pH 53,58,60,67 . In addition, the effect of the modified microbiome on gut gene expression, structure, and function (as it influences physiological processes such as digestion or metabolism and prevents colonization by pathogenic bacteria 53,68 ) will be an area for future study.…”

Probiotic effects of mixture of Groenewaldozyma salmanticensis and Gluconacetobacter liquefaciens on growth and immune responses in Paralichthys olivaceus

“…Vibrio scophthalmi was initially isolated from the intestines of juvenile turbot as non‐pathogenic (Cerda‐Cuellar et al ). Vibrio scophthalmi was reported as a major species in GI tract of S. senegalensis (Tapia‐Paniagua et al ). This species was observed to be the dominant bacterial population in the intestine of healthy reared flat fish including turbot ( Scophthalmus maximus ) (Cerdá‐Cuéllar and Blanch ) and S. senegalensis (Tapia‐Paniagua et al ).…”