Browsing by Author "Perera, Erick"
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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.
- High plant protein diet impairs growth performance and intestinal integrity in greater amberjack (Seriola dumerili): Molecular and physiological insightsPublication . Fuentes, Juan; Fonseca, Filomena; Gregorio, Silvia; Kussaba Miguel, Larissa; Perera, Erick; Alarcón-López, Francisco J.; Martos-Sitcha, Juan A.The Mediterranean aquaculture industry that produces mainly seabream and seabass is exploring alternative plant-based protein sources for fish feeds together with the diversification of fish species. Effective plant-based formulations require diverse sources and additives to maintain fish welfare and growth, which is especially important for carnivorous species. In this scenario, the objective of the present study was to evaluate the impact of a high percentage of fishmeal replacement with protein of plant origin in Seriola dumerili, a fast-growing species with a high protein requirement. Two diets were developed: MAP (marine animal protein) with a protein content of 92 % of animal origin and PPB (plant protein blend) with a 50 % replacement of protein of animal origin with plant protein. We combined electrophysiology measurements with expression analysis of claudins and members of the SLC superfamily of solute carriers to unravel and characterise putative markers of intestinal integrity and absorption. The replacement resulted in shorter and lighter fish with a reduction in growth rate (SGR) from 2.6 to 2. We simultaneously observed lower transepithelial tissue resistance (TER), lower permeability, and decreased cld12 expression in the anterior intestine. In addition, we demonstrated a strong regiondependent electrogenic transport of essential amino acids, with the mid-intestine having the highest transport capacity. The comparative study performed in the mid-intestine with fish fed the MAP or the PPB diets exposed a negative effect of dietary replacement with plant protein. No significant dietary impact on di- and tri-peptide transporters (SLC15) was found at the molecular level. However, a clear region-dependent expression pattern of slc15a1, slc15a2, and slc15a4 was observed, which warrants further investigation. The expression pattern of slc7a5 showed the effect of the diet, but in contrast, the diet and intestinal region affected the expression of its functionally associated slc3a1 and slc3a2 for amino acid antiport, with the strongest effects in the posterior intestine. The integrity and absorption impairments detected in response to protein source replacement will likely underlie the significant growth differences observed between the two dietary regimes.
- 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.