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Embryonic temperature influences the mucosal responses of Atlantic salmon alevins to a bacterial challenge
Get PDFThe present work investigated the effects of embryonic temperature on the responses of Atlantic salmon (Salmo salar) alevins to a bacterial challenge using Yersinia ruckeri as a model pathogen. Embryos were reared at 4°C, 6°C, and 8°C from fertilization to the eyed-egg stage. Alevins, before the start of feeding, were challenged with the pathogen, and mortality and early immune responses in mucosal organs were assessed. Fish from the 4°C and 6°C groups exhibited higher survival probabilities than those from the 8°C group 72 h post-infection. Mild histopathological changes were observed in the gills and skin across all temperature groups, with bacterial antigen detected in the secondary lamellae of gills and in the skin epithelial and basal layers. Gene expression profiling revealed slightly distinct immune gene expression patterns in low-temperature groups (4°C and 6°C) compared to the 8°C group. Gelsolin (gsn) expression increased in the skin across all temperature groups at 72 h post-infection. Claudin (cldn4) and collagen (col1a) were only upregulated in the skin of the 4°C group, while heat shock protein 70 (hspa1a) was downregulated in the gills of infected fish at 72 h compared to controls. Toll-like receptor 13 (tlr13) expression increased in infected fish at 24 h compared to controls. In the 6°C and 8°C groups, gsn expression also increased at 72 h post-infection. Cldn4 expression increased only in the gills of 8°C infected fish. This study revealed that low embryonic temperature could influence survival and mucosal immune defences following a bacterial challenge in Atlantic salmon alevins. Embryonic temperature influences the mucosal responses of Atlantic salmon alevins to a bacterial challengeacceptedVersio
Domesticating the wild through escapees of two iconic mediterranean farmed fish species
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Environmental challenge trials induce a biofluorescent response in the green sea urchin Strongylocentrotus droebachiensis
Get PDFStress in sea urchins leads to high mortality and economic losses in both the environment and aquaculture. The green sea urchin Strongylocentrotus droebachiensis has been documented emitting complex biofluorescence, yet how this responds to external stressors is unknown. Adult sea urchins (n = 210) were divided between control (n = 30) and experimental groups (n = 180), using three transport variables: out of water, in water at elevated temperatures, (warm-water) and in water at seawater temperature (cold-water). Hyperspectral imaging of external fluorescence and fluorospectrometric analysis on coelomic fluid was measured at five intervals (hour 0,3,6,9,12). External green emissions (∼580 nm) responded to all treatments, peaking at h9. External red emissions (∼680–730 nm) in the cold-water remained low until an h9 peak. The warm water increased emissions at each interval, peaking at h9. The out of water gradually increased, with the highest at h12. The coelomic fluid fluorescence (∼680 nm) was low to nonexistent except in warm-water, whose elevated levels suggest that fluorescent emissions are a measurable byproduct of internal adaptation(s) to stress. Early detection of fluorescent emissions (broken spines, lesions) may prevent economic losses. The observed link between fluorescence and the applied stressors provides a baseline for developing non-invasive technology for improving echinoderm welfare.Environmental challenge trials induce a biofluorescent response in the green sea urchin Strongylocentrotus droebachiensispublishedVersio
Investigation of the Effectiveness of Barrier Layers to Inhibit Mutagenic Effects of Recycled LDPE Films, Using a Miniaturized Ames Test and GC-MS Analysis
Get PDFTo fulfil the European Green Deal targets and implement a circular economy, there is an urgent need to increase recycling rates of packaging materials. However, before recycled materials can be used in food contact applications, they must meet high safety standards. According to the European Food Safety Authority (EFSA), a worst-case scenario must be applied and unknown substances must be evaluated as being potentially genotoxic. The Ames test, which detects direct DNA-reactive effects, together with chromatographic analysis is very promising to complement risk assessment. This study aims to evaluate the effectiveness of functional barriers in ten different samples, including virgin and recycled LDPE foils. FT-IR analysis did not show major differences between virgin and recycled films. Light microscopy revealed differences in quality and an increased number of particles. GC-MS analysis detected and quantified 35 substances, including eight unknowns. Using a miniaturized version of the Ames test, four of ten samples tested positive in two individual migrates up to a dilution of 12.5%. All virgin LDPE materials tested negative; however, recycled material F showed an increased mutagenic activity, with an n-fold induction up to 28. Samples with functional barriers lowered migration and reduced mutagenicity. Nonetheless, further investigations are needed to identify possible sources of contamination.publishedVersio
Assessing the potential of fluorescence as a monitoring tool for reproductive tissue in selected macroalgae species
Get PDFBiofluorescence in certain seaweed species has been studied in association with their respective chlorophyll type and concentration. However, there is a paucity of information on the biofluorescent signature of macroalgal species at different life stages. Here we document that hyperspectral imaging differentiates between the fluorescent signatures of 5 macroalgal species (Ascophyllum nodosum, Fucus vesiculosus, Laminaria digitata, Palmaria palmata, and Saccharina latissima) collected from Tromsø, northern Norway (69-70 °N). Non-reproductive (NR) blades were collected for all species and reproductively mature blades (R) with sori were collected for three species. Hyperspectral imaging of collected blades was conducted under excitation lighting (~445 nm). We further assessed whether biofluorescence is reflected in the reproductive phenology of three selected species, L. digitata, P. palmata, and S. latissima. The spectral radiance of fluorescence emissions was found to be consistently different between R and NR blades. The greatest difference between R and NR blades was between the rhodophyte P. palmata (0.0075 W nm-1sr-1m-2 at 725 nm) followed by the phaeophytes L. digitata (0.03 W nm-1sr-1m-2 at 730-740 nm) and S. latissima (0.00225 W nm-1sr-1m-2 at 735-745 nm). Biofluorescence monitoring with hyperspectral imaging should be considered for further applicability in commercial seaweed operations.publishedVersio
Is Pulsed Electric Field (PEF) a Useful Tool for the Valorization of Solid and Liquid Sea Bass Side Streams?: Evaluation of Nutrients and Contaminants
Get PDFIn this study, fresh sea bass’s (Dicentrarchus labrax) heads, skin, viscera, and muscle were evaluated for their potential valorization as a source of nutrients and bioactive compounds. For this purpose, a pulsed electric field (PEF) treatment (1.0 kV/cm field strength and 220.5 kJ/kg specific energy for head, 3.0 kV/cm and 299.4 kJ/kg for skin, 3.0 kV/cm and 123.7 kJ/kg for viscera and muscle) was used. Subsequently, extraction processes were carried out using either 100% water or 50% ethanol. Protein assessment (protein content and bioactive peptides’ identification), as well as ICP-MS analysis of minerals and heavy metals, was conducted on both the solid matrices and liquid extracts. The findings indicate that the choice of solvent (100% water or 50% ethanol) and PEF treatment significantly (p < 0.05) affected protein recovery in the sea bass side streams liquid extracts, while a considerable protein amount was retained in the solid matrices. Furthermore, the ICP-MS analysis of minerals revealed that PEF treatment significantly (p < 0.05) improved mineral recovery in the head and muscle liquid extracts. However, a considerable amount of minerals remained in the solid matrices. Lower contents of heavy metals were found in the liquid extracts compared to the solid matrices, being anyway the quantities of the five heavy metals analyzed within edible and safe limits. Additionally, the total antioxidant capacity (TAC) of sea bass side stream extracts was assessed to measure the potential antioxidant bioactive compounds in the liquid extracts. PEF treatments significantly (p < 0.05) increased the TAC of the liquid extracts from sea bass viscera, as opposed to other side streams. Both 100% water and 50% ethanol were effective as extraction solvents, promoting the recovery of high-added-value compounds not only from the liquid extracts but also from solid matrices. Thus, PEF pre-treatment can be considered a valuable technique to enhance fish side stream valorization.publishedVersio
Breaking down barriers: live or dehydrated dietary whole black soldier fly larvae supplementation in slow growing chickens preserve meat quality and sensory traits
Get PDFThis study investigated the effects of supplementing the diet of a slow-growing autochthonous chicken breed with dehydrated or live Black Soldier Fly Larvae (BSFL) on meat quality and sensory attributes. The research, conducted at the University of Turin, Italy, involved 144 male birds distributed in three experimental groups. The control group (C) was fed a basal diet in which soybean meal was completely substituted with alternative ingredients. The 2 experimental groups were administered a diet identical to the control group but supplemented with either whole dehydrated black soldier fly larvae (DL) or whole live black soldier fly larvae (LL) at a level equal to 5% expected daily feed intake of dry matter. We evaluated the following parameters: nutrient intake, slaughtering performance, physical and nutritional meat quality, fatty acid composition, proteomics, and sensory characteristics. The results demonstrated BSFL supplementation to have no detrimental effects on overall meat quality or sensory attributes. Specifically, there were no significant differences in physical meat quality parameters, nutritional composition, lipid oxidation, or protein digestibility between control and BSFL-fed groups. Fatty acid analysis revealed higher concentrations of lauric and myristic acids in BSFL-fed chicken breast (p < 0.005), suggesting potential nutritional benefits from the supplement. The proteomic analysis also showed no significant differences in the expression of abundant proteins in the breast meat between groups, indicating minimal physiological impact of BSFL supplementation. Overall, this study provides reassurance to consumers and industries about the suitability of BSFL as a sustainable feed supplement for poultry that also offers potential benefits in terms of optimizing the fatty acid profile of chicken meat.publishedVersio
Live storage of kelp under stressful conditions led to higher iodine reductions during subsequent blanching
Get PDFKelp growers and the food industry, as well as food researchers, are currently finding methods for controlling the iodine content of kelp intended for food as this is one of the major obstacles to entering a profitable market. Kelps are rich sources of dietary iodine since iodine is up-concentrated in algal tissue and utilized as an inorganic antioxidant during exposure to stress. As kelp contains much more iodine than any other food source, it is warranted to reduce the amount of iodine in the biomass prior to consumption, since both iodine deficiency and excess can cause health problems. Iodine is typically removed post-harvest using traditional methods such as blanching. In the present work, we attempted to utilize inherent stressors, i.e., intermediate storage (3 days) with high light exposure and low turnover of water, to reduce the iodine content prior to processing. Furthermore, we assessed the effect on subsequent blanching, comparing samples stored in tanks and not stored samples. The iodine content was slightly reduced when comparing storage to no storage, but in most cases not significantly so. However, after subsequent blanching, there was a pronounced added reduction for stored samples (87 % reduction) compared to not stored samples (80 % reduction). Although the differences are smaller than we expected, our research shows that using post-harvest intermediate storage of kelp may alter the iodine content post-processing. Fine-tuning the stressors and conditions could lead to new possibilities for iodine reduction.Live storage of kelp under stressful conditions led to higher iodine reductions during subsequent blanchingpublishedVersio
Variable time delay estimation in continuous industrial processes
Get PDFDigital sensors and machine learning enable efficiency improvements in production processes, through process monitoring, anomaly detection, soft sensing, and process control. However, the development of such solutions requires several data preprocessing steps. In continuous processes, a crucial part of the data preparation is adjusting for time delays between different sensors. This is necessary to ensure that each sensor measurement relate to the same volume of materials going through various processing steps. This study provides an overview of data-driven methods for estimating time lags between sensors in continuous processes. The methods are assessed in a large simulation study, on data sets with different sample sizes, model complexities and autocorrelation functions. Our results shows that most methods work well if the relationships are close to linear, but more flexible metrics like distance correlation and maximum information coefficient are needed in more complex systems. Finally, we present a real industrial example to illustrate some real-world aspects of the variable time delay estimation process.publishedVersionpublishedVersio
Reproductive performance of lumpfish (Cyclopterus lumpus, L. 1758) females: Effects of integrated photoperiod and temperature manipulations on sexual maturation and spawning
Get PDFA successful control of sexual maturation is crucial for year-round production of lumpfish juveniles destined as cleaner fish in Atlantic salmon aquaculture. This study investigated the combined effects of photoperiod and temperature manipulations on sexual maturation and spawning in lumpfish females. Lumpfish juveniles were exposed to simulated natural and nine-month compressed annual photoperiods, with subsequent temperature elevation. Body weight (BW), condition factor (K), gonadosomatic index (GSI), ovarian development, plasma levels of 17β-estradiol (E2), testosterone (T) and 11-ketotestosterone (11-KT), and spawning were assessed. Compressing the natural photoperiod caused a clear increase and decrease in GSI, T, 11-KT and E2 towards and during the spawning period. Before the temperature elevation, GSI, T, 11-KT, E2 and ovarian development were advanced in the compressed photoperiod. After the temperature elevation, GSI, T, 11-KT and E2 fluctuated more in the compressed photoperiod, while in the natural photoperiod, E2 declined, and GSI, T and 11-KT increased. Spawning was advanced by 1 month in the compressed photoperiod compared to the natural photoperiod. Temperature elevation led to higher levels, earlier peaks and declines of T, 11-KT or E2 in both photoperiods, and advanced spawning by 1.5 months in the compressed photoperiod compared to the natural photoperiod. Temperature elevation also led to increased ovulation recruitment and increased cumulative weight of spawned eggs in the natural photoperiod. Compressing the natural photoperiod and elevating temperature can thus advance sexual maturation and spawning in lumpfish females. Due to the lower amounts of spawned egg weights in the high temperature compressed photoperiod, further studies on effects of photoperiod and timing of temperature manipulations on spawning, fecundity and egg quality could optimize the photothermal manipulations on lumpfish broodstock.publishedVersio