Browsing by Author "Martos-Sitcha, Juan Antonio"
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- Biotechnological treatment of microalgae enhances growth performance, hepatic carbohydrate metabolism and intestinal physiology in gilthead seabream (Sparus aurata) juveniles close to commercial sizePublication . Molina-Roque, Luis; Bárany, André; Sáez, María Isabel; Alarcón, Francisco Javier; Tapia, Silvana Teresa; Fuentes, Juan; Mancera, Juan Miguel; Perera, Erick; Martos-Sitcha, Juan AntonioThe aim of this work was to evaluate the effects on growth performance, intermediary metabolism and welfare of the inclusion of two commercial microalgae-based ingredients called LB-ChromaBream (LB-CB) and LB-ChromaBream-plus (LB-CBplus) in the diet of gilthead seabream (Sparus aurata) close to commercial size. For this purpose, fish of similar to 182 g of initial body mass were fed to satiety (ad libitum) for 41 days with three different diets: (i) CONTROL diet (CTRL), with a commercial-like formulation; (ii) LB-CB diet, with a 10 % inclusion of microalgal product; (iii) LB-CBplus diet, with a 10 % inclusion of the same product but enzymatically hydrolysed to increase the bioavailability of the nutrients. The results obtained show that the use of these microalgal products leads an overall improvement in productive parameters in terms of growth (15 % in SGR) and feed efficiency (11 %), as well as a significant reduction in circulating cortisol with the LB-CBplus diet. Observations on plasma and liver metabolites, and particularly on hepatic metabolic enzymes, collectively indicate that microalgae supplementation of feed lead to a better use of carbohydrates as a source of energy in the liver and other tissues, potentially sparing triglycerides within this tissue, and a channelling hepatic triglycerides to fuels growth. Finally, the specimens fed the supplemented diets experienced a substantial improvement in intestinal health, achieved by longer intestines, a higher transepithelial resistance and better apparent permeability measured by electrophysiological methods, especially those fed LB-CBplus, which could explain the increase in productive performance by improving nutrient assimilation. In conclusion, this study shows that the experi-mental feeds, especially the one containing biotechnologically treated microalgae, are suitable for improving some important indicators of growth performance and physiological condition of gilthead seabream, thus revealing the potential for their inclusion in new functional feeds for this species at an advanced stage of the production cycle.
- Dietary butyrate helps to restore the Intestinal status of a marine teleost (Sparus aurata) fed extreme diets low in fish meal and fish oilPublication . Estensoro, Itziar; Ballester-Lozano, Gabriel; Benedito-Palos, Laura; Grammes, Fabian; Martos-Sitcha, Juan Antonio; Mydland, Liv-Torunn; Calduch-Giner, Josep Alvar; Fuentes, Juan; Karalazos, Vasileios; Ortiz, Alvaro; Overland, Margareth; Sitja-Bobadilla, Ariadna; Perez-Sanchez, JaumeThere is a constant need to find feed additives that improve health and nutrition of farmed fish and lessen the intestinal inflammation induced by plant-based ingredients. The objective of this study was to evaluate the effects of adding an organic acid salt to alleviate some of the detrimental effects of extreme plant-ingredient substitution of fish meal (FM) and fish oil (FO) in gilthead sea bream diet. Three experiments were conducted. In a first trial (T1), the best dose (0.4%) of sodium butyrate (BP-70 (R) NOREL) was chosen after a short (9 weeks) feeding period. In a second longer trial (T2) (8 months), four diets were used: a control diet containing 25% FM (T2-D1) and three experimental diets containing 5% FM (T2-D2, T2-D3, T2-D4). FO was the only added oil in D1, while a blend of plant oils replaced 58% and 84% of FO in T2-D2, and T2-D3 and T2-D4, respectively. The latter was supplemented with 0.4% BP-70. In a third trial (T3), two groups of fish were fed for 12 and 38 months with D1, D3 and D4 diets of T2. The effects of dietary changes were studied using histochemical, immunohistochemical, molecular and electrophysiological tools. The extreme diet (T2-D3) modified significantly the transcriptomic profile, especially at the anterior intestine, up-regulating the expression of inflammatory markers, in coincidence with a higher presence of granulocytes and lymphocytes in the submucosa, and changing genes involved in antioxidant defences, epithelial permeability and mucus production. Trans-epithelial electrical resistance (Rt) was also decreased (T3-D3). Most of these modifications were returned to control values with the addition of BP-70. None of the experimental diets modified the staining pattern of PCNA, FABP2 or ALPI. These results further confirm the potential of this additive to improve or reverse the detrimental effects of extreme fish diet formulations.
- From invasion to fish fodder: inclusion of the brown algae rugulopteryx okamurae in aquafeeds for european sea bass dicentrarchus labrax (L., 1758)Publication . Fonseca, Filomena; Fuentes, Juan; Vizcaíno, Antonio Jesús; Alarcón, Francisco Javier; Mancera, Juan Miguel; Martínez-Rodríguez, Gonzalo; Martos-Sitcha, Juan AntonioIn keeping with the premises of Blue Circular Economy in the European Union, the present study explored the possibility of using the invasive brown alga Rugulopteryx okamurae in aquafeeds for European sea bass (Dicen-trarchus labrax). Assuming the raw algae biomass could negatively impact animal performance, four experi-mental formulations were prepared, by including macroalgae material at 5%, using crude (CR), enzymatically hydrolysed and fermented (EF), enzymatically hydrolysed (E), or fermented (F) R. okamurae biomass, which we tested against a control feed (CT). To evaluate the effects of the experimental diets, besides animal growth performance and biometric parameters, we devised a toolbox focused on the intestine and intestinal function: i) ex-vivo epithelial resistance and permeability in Ussing chambers; ii) microbiota composition through NGS; iii) expression profiles of selected markers for epithelial integrity, transport, metabolism, and immune response, by qPCR. Our results show differentiated allometric growth among diets, coupled with intestinal epithelium al-terations in permeability, integrity, and amino acid transport. Additionally, evidence of microbiota dysbiosis and contrasting immune responses between experimental diets, i.e. pro-inflammatory vs. anti-inflammatory, are also described. In conclusion, we believe that R. okamurae could be a suitable resource for aquafeeds for the European sea bass, although its use requires a pre-treatment before inclusion. Otherwise, while the fish still have a positive growth performance, the gastrointestinal tract pays a toll on the integrity, transport, and inflammatory processes.
- Low dietary inclusion of nutraceuticals from microalgae improves feed efficiency and modifies intermediary metabolisms in gilthead sea bream (Sparus aurata)Publication . Perera, Erick; Sánchez-Ruiz, David; Sáez, María Isabel; Galafat, Alba; Barany, A.; Fernández-Castro, Miriam; Vizcaíno, Antonio Jesús; Fuentes, Juan; Martínez, Tomás Francisco; Mancera, Juan Miguel; Alarcón, Francisco Javier; Martos-Sitcha, Juan AntonioThe aim of this work was to evaluate two functional feeds for the gilthead seabream, Sparus aurata, containing low inclusion of two microalgae-based products (LB-GREENboost, LBGb; and LB-GUThealth, LBGh). Fish (12-13 g) were fed for 13 weeks a control diet or one of the four diets supplemented with both products at 0.5% or 1%. LBGb and LBGh did not affect specific growth rate or survival, but increased feed efficiency by decreasing feed intake and enlarging the intestines. LBGb increased hepatosomatic index and reduced cortisol levels in plasma, while both products lowered plasma lactate. Extensive metabolite and metabolic enzyme profiling revealed that microalgae supplementations, especially 1% LBGh: (i) decrease plasma lactate and increase hepatic glycogen, (ii) reduce hepatic gluconeogenesis, (iii) enhance hepatic lipogenic activity and lipid secretion, (iv) led fish to double triglyceride content in muscle and to stimulate its lipid oxidative capacity, and (v) increase the content of monounsaturated fatty acids and the omega-3 alpha-linolenic acid in muscle. This study demonstrates that both microalgae-based products are suited to improve feed efficiency and orchestrate significant changes in the intermediary metabolism in gilthead seabream juveniles.
- Vasotocin and isotocin regulate aquaporin 1 function in the sea breamPublication . Martos-Sitcha, Juan Antonio; Campinho, Marco António; Miguel Mancera, Juan; Martinez-Rodriguez, Gonzalo; Fuentes, JuanAquaporins (AQPs) are specific transmembrane water channels with an important function in water homeostasis. In terrestrial vertebrates, AQP2 function is regulated by vasopressin (AVP) to accomplish key functions in osmoregulation. The endocrine control of aquaporin function in teleosts remains little studied. Therefore, in this study we investigated the regulatory role of vasotocin (AVTR) and isotocin (ITR) receptors in Aqp1 paralog gene function in the teleost gilthead sea bream (Sparus aurata). The complete coding regions of Aqp1a, Aqp1b, AVTR V1a2-type, AVTR V2-type and ITR from sea bream were isolated. A Xenopus oocyte-swelling assay was used to functionally characterize AQP1 function and regulation by AVT and IT through their cognate receptors. Microinjection of oocytes with Aqp1b mRNA revealed regulation of water transport via PKA (IBMX+forskolin sensitive), whereas Aqp1a mRNA injection had the same effect via PKC signaling (PDBU sensitive). In the absence of expressed receptors, AVT and IT (10(-8) mol l(-1)) were unable to modify AQP1 function. AVT regulated AQP1a and AQP1b function only when the AVTR V2-type was co-expressed. IT regulated AQP1a function, but not AQP1b, only when ITR was present. Considering that Aqp1a and Aqp1b gene expression in the sea bream intestine is highly salinity dependent in vivo, our results in ovo demonstrate a regulatory role for AVT and IT in AQP1 function in the sea bream in the processing of intestinal fluid to achieve osmoregulation.