Kluyveromyces fragilisRNA extract supplementation promotes growth, modulates stress and inflammatory response in zebrafish

Abstract

Due to the undesirable consequences associated with antibiotics use, researchers and food producers have studied alternative feeding, for the control of fish diseases and animal welfare improvement. However, the beneficial properties of RNA yeasts extract in aquaculture have been barely considered. The present study investigated the beneficial properties of RNA yeast extract from Kluyveromyces fragilis on survival rate, weight and length as well as on molecular pathways involved in growth, immuno‐system and oxidative stress using zebrafish (Danio rerio) as an experimental model. The yeast extract has been administrated to zebrafish at three different concentrations (60–180–300 ppm) via zooplankton (Artemia salina) for 21 days. Results highlighted yeast extract RNA capability to enhance growth and to improve larvae survival rate in a dose‐dependent manner. In fact, gene expression data showed the ability of the RNA yeast extract to up‐regulate genes involved in growth and to restore stress‐related condition due to the early larval development coupled with the RNA yeast extract administration. In addition, gene expression showed that RNA yeast extract acts as inflammatory‐reducer, but did not enhance the immune response. Histological analysis showed that all three treated groups displayed a thicker gut epithelium, higher intestinal crypts coupled with higher enterocytes lengths compared to control group. In conclusion, these findings provide a large gene network through which yeast RNA extract acts and, by inducing transcriptional changes, modulate the physiological control of growth and inflammatory response coupled with the increase in length and dry weight, together with a higher survival ratio and an intestinal architecture amelioration.

Salinity, Temperature and Ammonia Acute Stress Response in Seabream (Sparus aurata) Juveniles: A Multidisciplinary Study

“…Variations in water quality parameters (temperature, salinity, ammonia content) can induce fish growth reduction influencing the expression of insulin-like growth factors ( igf1 and igf2 ) and myostatin ( mstn ) [ 14 , 15 , 16 , 17 , 18 , 19 ] by the activation of stress response system. In fish, both IGF complex and myostatin play a key role in growth regulation [ 10 , 20 , 21 , 22 , 23 ]. The IGF complex includes the two highly conserved primary ligands (IGF-I and IGF-II), high-affinity transmembrane receptors that belong to the insulin/IGF receptor family and six IGF-binding proteins (IGFBP-1 to -6) [ 22 , 24 , 25 ].…”

Yeast-extracted nucleotides and nucleic acids as promising feed additives for European sea bass (Dicentrarchus labrax) juveniles

“…In particular, IL-1b and TGF-b1 mRNA level were respectively downregulated and upregulated in Nile tilapia fed guanidinoacetic acid supplemented diet for 60 days. Similarly, anti-inflammatory effect was observed in zebrafish (Danio rerio) fed a diet supplemented with RNA yeast extract; in this case proinflammatory cytokines such as IL-1, IL-8 and TNF-a were downregulated, whereas the anti-inflammatory cytokine IL-10 was upregulated or not modulated depending on the growth stage of the investigated larvae (Falcinelli et al, 2018). In our study, we observed opposite expression trends of IL-1b and TGF-b in accordance to their pro-and anti-inflammatory roles respectively.…”

Reducing the Use of Antibiotics in European Aquaculture with Vaccines, Functional Feed Additives and Optimization of the Gut Microbiota

“…These phyla and Bacteroidetes usually represent up to 90% of fish intestinal microflora in different marine and freshwater species, constituting the "core gut microbiota" [75,76]. In trout, the dietary administration of insects leads to a significant increase in gut Firmicutes and Actinobacteria and, in particular, in lactic acid bacteria (LAB) such as Aerococcaceae, Leuconostocaceae, Enterococcaceae, Lactobacillaceae, Leuconostocaceae, and Carnobacteriacee [71,72,74], which are generally considered beneficial microorganisms and used as probiotics for fish and other vertebrates [77][78][79][80]. Several studies reported positive effects of LAB on disease resistance, survival, and growth parameters for a wide variety of European fish species [81,82].…”