Biochemical features and modulation of digestive enzymes by environmental temperature in the greater amberjack, Seriola dumerili

The study of fish digestive biochemistry is essential to understand factors that affect the net efficiency of food transformation and growth, and therefore aquaculture profitability. The aim of the present study was to assess the activity and functional characteristics of key digestive enzymes in juveniles of greater amberjack (Seriola dumerili), as well as the possible modulation of their relative importance by water temperature. For that, a combination of biochemical assays and substrate-SDS-PAGE were used. Under physiological conditions pepsin activity was negligible. Chymotrypsin was the most active enzyme in the digestive tract of the greater amberjack, while lipase was the enzyme with lower activity, though both enzymes in addition to trypsin were responsive to water temperature as revealed by discriminant analysis. Seriola dumerili showed to have pH-sensitive and, except for chymotrypsin, thermally robust proteases. Inhibition assays showed the major importance of serine proteases and revealed inverse trypsin and chymotrypsin responses to environmental temperature, with higher trypsin contribution in 26°C-fish while higher chymotrypsin contribution in 18°C-fish. Zymograms revealed three isotrypsin and three isochymotrypsin enzymes, with no variation in the presence of particular isoforms among rearing temperatures. However, they confirmed the role of chymotrypsin activity in providing digestive plasticity, with one of the isoforms being more active at lower temperatures. Thus, results indicate that variation in the relative contribution of chymotrypsin isoenzymes to a particular environmental temperature occurs due to different physic-chemical features of isoforms as a source of functional flexibility. This study assessed for the first time the effects of rearing temperature on greater amberjack digestive enzymes, increasing the knowledge on its digestive biochemistry, and aiding in the improvement of management practices for this species industrialization

Editorial: Food of the future: Algae and aquaculture

Food and feed shortage are serious problems challenging the sustainable development of human society. Besides, food-related health is becoming an emerging topic attracting researchers' attentions...Peer reviewe

Gut transit of daily consecutive meals in greater amberjack juveniles reared at different temperatures

Feed passage time throughout the digestive tract of three daily consecutive meals containing three different inert markers respectively and the gut luminal ionic conditions generated during a daily cycle have been examined in juveniles of greater amberjack (Seriola dumerili) growing at 18, 22 and 26 °C of water temperature. As expected, transit time tended to decrease with increasing temperature in the tested range. However, each meal progressed in a different manner affecting the ionic daily pattern within the tract lumen and the residence time within the different gut segments, two parameters of primary importance for the digestion efficiency. At 22 and 26 °C the gastric acidification effort was focused on the first meal whilst at 18 °C it was on the second and third meal. Intestinal alkalinisation was maintained during more hours at 22 °C than at 18 °C and 26 °C coinciding with the moments of highest chyme content in the intestine. At 26 °C, the three meals transited fast enough to progress clearly as separate batches. On the contrary, at 18 and 22 °C the consecutive meals became mixed in the stomach and intestine. Transit time was progressively shorter from the first to third meals at 18 and 22 °C, while at 26 °C it was shorter for the second meal and similar for the first and third meals when 95% total gut evacuation was considered. Total transit time ranged from 12 to 24 h approximately and the posterior intestine was completely emptied before the first morning meal in all cases. Interestingly, the residence time of ingested food in the middle intestine was longer at 22 °C than at the other two temperatures.publishedVersio

Replacement of Antarctic krill (Euphausia superba) by extruded feeds with different proximate compositions: effects on growth, nutritional condition and digestive capacity of juvenile European lobsters (Homarus gammarus, L.)

Extruded feeds are widely used for major aquatic animal production, particularly for finfish. However, the transition from fresh/frozen to extruded/pelleted feeds remains a major obstacle to progressing sustainable farming of European lobster ( Homarus gammarus). The aim of the present study was to investigate the effects of using extruded feeds with different protein levels and lipid/carbohydrate ratios on growth, feed utilisation, nucleic acid derived indices (sRD) and digestive enzymatic activity of H. gammarus juveniles. Six extruded feeds were formulated to contain two protein levels (400 and 500 g/kg), with three lipid/carbohydrate ratios (LOW - 1:3; MEDium - 1:2; HIGH - 1:1). The extruded feeds were tested against Antarctic krill (Euphausia superba) used as control (CTRL). Overall, the CTRL and 500MED feed supported the highest growth and nutritional condition estimated by means of sRD, while the poorest results were observed for the 400HIGH and 400MED groups. The FCR was significantly lower in the CTRL than all extruded feeds, among which the most efficient, i.e., lower FCR, was the 500MED. The highest activity of trypsin and amylase in lobsters fed the 400MED and 400HIGH feeds points to the activation of a mechanism to maximise nutrients assimilation. The highest lipase activity observed for the 500LOW and 500MED groups indicates a higher capacity to metabolise and store lipids. Overall, the results suggest that the 500MED feed (500 g/kg protein, 237 g/kg carbohydrates and 119 g/kg lipids) is a suitable extruded feed candidate to replace Antarctic krill, commonly used to grow lobster juveniles.E114944, UIDB/04326/2020info:eu-repo/semantics/publishedVersio

Osteoporosis en alcoholismo crónico : un problema infravalorado. Incidencia y complicaciones de las fracturas en el paciente alcohólico

Main goal. To estimate the incidence of pathologic fractures and associated complications in patients in follow-up for moderate to severe chronic alcoholism by the Unidad de Conductas Adictivas (UCA) of our health area. To highlight the importance of recognizing osteoporosis in patients with chronic alcoholism in order to establish strategies for prevention of both primary and secondary fractures. Material and methods. Retrospective analysis of patients in follow-up for chronic alcoholism by the UCA between 2014 and 2018 that required assessment by the Orthopedics Unit for fractures during that period, excluding fractures in the context of politraumatism. In addition, the complications derived from these fractures were collected and it was determined whether bone densitometry (BMD) was indicated following the main osteoporosis guidelines. Results. The incidence rate of fractures due to low-energy trauma in the selected population during the follow-up period was 7.2 for every 1,000 patients / year. 41% of the 44 study patients suffered new fractures during this period. 33% of the patients with fractures that required surgical treatment suffered major complications. 100% of the patients fulfilled criteria for BMD after the first traumatic event, despite only 20% of them being ultimately performed. Conclusions. The prevalence of fractures and associated complications in alcoholic patients is significantly higher than in the general population. It is necessary to stress the importance of both primary and secondary prevention of pathologic fractures in alcoholic patients, and if they occur, osteosynthesis techniques adapted to an osteoporotic bone should be applied

Effect of increased rearing temperature on digestive function in cobia early juvenile

The present study is focused to elucidate the main characteristics of the digestive function of this carnivorous fast-growing fish living at high temperatures. With this aim, we have examined the effects of an increased temperature from 30 to 34 °C on the daily pattern of gastrointestinal pH, enzymatic proteolytic digestive activity and the feed transit time in early juveniles of cobia (Rachycentron canadum), a species living in tropical and subtropical waters with an increasing aquaculture production. Fish were fed two meals a day. Gastric luminal pH was permanently acidic (mean pH values: 2.76-4.74) while the intestinal pH increased from neutral/slightly acidic to slightly alkaline when the digesta was present, with an increasing alkalinity from proximal to distal intestine (mean pH values: 6.05 to 7.69). The temperature did not affect the gastric pH but a slightly higher acidity was induced in the intestine at 34 °C. Pepsin activity showed a daily rhythm at 30 °C with maximum in the middle of the light period, while at 34 °C some hourly changes coinciding with feed adding without a clear daily trend during the 24-h period were observed. The trypsin activity exhibited a daily rhythm at both temperatures with an increase after morning feeding to reach a maximum several hours later. Average pepsin activity during the daily cycle was slightly higher at 34 °C (6.1 and 7.3 U mg-1 BW at 30 and 34 °C respectively), but values were significantly different only at 8 and 24 h after the morning meal. Similarly, the trypsin activity was significantly affected by the temperature only at 8 and 16 h after the morning meal, but daily activity averages were similar (1.20 and 1.29 U g-1 BW at 30 and 34 °C respectively). The partial transit rates of the first meal in the stomach for each period inter-samplings were higher during the first 4-h period and decreased progressively along the rest of the 24-h cycle at both temperatures, but no significant differences were detected at 30 °C. In addition, the transit was notably faster at 34 °C particularly during the first 8 h after feeding, with rates between 100 and 65% of total volume displaced (intake or released) during each 4-h period. In the intestine the transit rate was relatively constant and similar at both temperatures during 12 h after feeding. Then the rates remained very low during the following 12 h. Residence time of the first meal was longer at 30 than at 34 °C, particularly in the stomach (12 h:02 min vs 4 h:54 min respectively). In the intestine the difference was not so large (8 h:18 min vs 6 h:24 min respectively). In a parallel study under same conditions, cobia reared at 30 °C grew faster and showed a more favorable feed conversion ratio than those at elevated temperature (34 °C). The present results indicate that at 34 °C, a subtle increase of proteolytic activity cannot compensate for the faster gut transit rate. Therefore, 30 °C is more appropriate temperature for the early on-growing of cobia because at higher temperatures the digestion efficiency decrease being one of the causes for a lower growth.Agência financiadora European Union (EU) 691150 MINECO, Spain + FEDER/ERDF contribution EFISHDIGESTAGL2014-52888 European Social Fund, the Operational Programme Human Potential IF/00482/2014/CP1217/CT0005 Portuguese Foundation for Science and Technology Portuguese Foundation for Science and Technology UDI/Multi/04326/2013 Norwegian Agency for Development Cooperation NORHED QZA-0485 SRV-13/0010info:eu-repo/semantics/publishedVersio

Effects of dietary curcumin in growth performance, oxidative status and gut morphometry and function of gilthead seabream postlarvae

An imbalance in the production and detoxification of reactive oxygen species and other oxidants can disrupt a l l types of cellular compounds, and lead to a state of oxidative stress. Preventing this state is essential to improve growth and health in animal production. Therefore, the aim of this work was to assess i f the dieta r y supple-mentation of curcumin cou l d improve the antioxidant status and intestine structu r e and functionalit y of gilthead seabream postlarvae, with the global objective of improving fish growth performance and robustness. Two experimental diets supplemented with different doses of curcumin (LOW and HIGH diets), and a commercial diet were fed to quadruplicate groups of postlarvae, for 20 days. At the end of the feeding trial fish fed the supple-mented diets significantly improved their antioxidant status compared to CTRL fed fish. LOW and HIGH fed fish presented lower protein oxidative damage (P 0.05). In conclusion, dieta r y curcumin supplementation was able to enhance gilthead seabream postlarvae robustness through a modulation of the oxidative status, increasing total antioxidant capacity and decreasing protein oxidative damage. This data pro-vide evidence that curcumin can be a suitable feed additive to promote heath status and robustness of fish at early stages of development, therefore contributing for the development and sustainabilit y of marine fish hatchery production.info:eu-repo/semantics/publishedVersio

Dietary curcumin promotes gilthead seabream larvae digestive capacity and modulates oxidative status

The larval stage is highly prone to stress due to the ontogenetic and metabolic alterations occurring in fish. Curcumin inclusion in diets has been shown to improve growth by modulating oxidative status, immune response, and/or feed digestibility in several fish species. The aim of the present work was to assess if dietary curcumin could promote marine fish larvae digestive maturation and improve robustness. Gilthead seabream larvae were fed a diet supplemented with curcumin at dose of 0 (CTRL), 1.5 (LOW), or 3.0 g/Kg feed for 27 days. From 4 to 24 days after hatching (DAH), no differences were observed in growth performance. At the end of the experiment (31 DAH) LOW larvae had a better condition factor than CTRL fish. Moreover, HIGH larvae showed higher trypsin and chymotrypsin activity when compared to CTRL fish. LOW and HIGH larvae were able to maintain the mitochondrial reactive oxygen species production during development, in contrast to CTRL larvae. In conclusion, curcumin supplementation seems to promote larvae digestive capacity and modulate the oxidative status during ontogeny. Furthermore, the present results provide new insights on the impacts of dietary antioxidants on marine larvae development and a possible improvement of robustness in the short and long term.ALG-01-0145-FEDER-029151info:eu-repo/semantics/publishedVersio

Ongrowing European fish species with feeds formulated with a by-product derived from cereal processing

Trabajo presentado en el congreso Aquaculture Europe 2023: Balanced Diversity in Aquaculture Development celebrado en Viena (Austria) entre el 18 y el 21 de septiembre de 2023.The cereal industry generates large amounts of residual by-products with high potential as feed ingredient for aquafeeds. Such raw materials could help to substitute protein and lipids from less sustainable sources such as soy concentrate, wheat flour or oils and reduce the competitiveness between the production of aquafeeds and the use of food for human consumption. In this study, one of these by-products, corn gluten feed, has been tested in dose-response experiments as ingredients in on-growing feeds for two European species (greater amberjack, Seriola dumerili; gilthead seabream, Sparus aurata). The final aim was to examine to what extent this more-sustainable and low-cost product can be used as alternate ingredient for fish feeds.Project SUSTAINFEED, EIT Food 21168, Co-funded by the European Union

PM060184, a new tubulin binding agent with potent antitumor activity including P-glycoprotein over-expressing tumors

PM060184 belongs to a new family of tubulin-binding agents originally isolated from the marine sponge Lithoplocamia lithistoides. This compound is currently produced by total synthesis and is under evaluation in clinical studies in patients with advanced cancer diseases. It was recently published that PM060184 presents the highest known affinities among tubulin-binding agents, and that it targets tubulin dimers at a new binding site. Here, we show that PM060184 has a potent antitumor activity in a panel of different tumor xenograft models. Moreover, PM060184 is able to overcome P-gp mediated resistance in vivo, an effect that could be related to its high binding affinity for tubulin. To gain insight into the mechanism responsible of the observed antitumor activity, we have characterized its molecular and cellular effects. We have observed that PM060184 is an inhibitor of tubulin polymerization that reduces microtubule dynamicity in cells by 59%. Interestingly, PM060184 suppresses microtubule shortening and growing at a similar extent. This action affects cells in interphase and mitosis. In the first case, the compound induces a disorganization and fragmentation of the microtubule network and the inhibition of cell migration. In the second case, it induces the appearance of multipolar mitosis and lagging chromosomes at the metaphase plate. These effects correlate with prometaphase arrest and induction of caspase-dependent apoptosis or appearance of cells in a multinucleated interphase-like state unrelated to classical apoptosis pathways. Taken together, these results indicate that PM060184 represents a new tubulin binding agent with promising potential as an anticancer agent.This work was supported by grants BIO2010-16351 (JFD), CAM S2010/BMD-2457 (JFD), CAM S2010/BMD-2353 (JMA), BFU2011-23416 (JMA) and PharmaMar-CSIC contracts. BP had a contract from Comunidad de Madrid