Impact of three commercial feed formulations on farmed gilthead sea bream (Sparus aurata, L.) metabolism as inferred from liver and blood serum proteomics

Background: The zootechnical performance of three different commercial feeds and their impact on liver and serum proteins of gilthead sea bream (Sparus aurata, L.) were assessed in a 12 week feeding trial. The three feeds, named A, B, and C, were subjected to lipid and protein characterization by gas chromatography (GC) and liquid chromatography-tandem mass spectrometry (LC-MS/MS), respectively. Results: Feed B was higher in fish-derived lipids and proteins, while feeds C and A were higher in vegetable components, although the largest proportion of feed C proteins was represented by pig hemoglobin. According to biometric measurements, the feeds had significantly different impacts on fish growth, producing a higher average weight gain and a lower liver somatic index in feed B over feeds A and C, respectively. 2D DIGE/MS analysis of liver tissue and Ingenuity pathways analysis (IPA) highlighted differential changes in proteins involved in key metabolic pathways of liver, spanning carbohydrate, lipid, protein, and oxidative metabolism. In addition, serum proteomics revealed interesting changes in apolipoproteins, transferrin, warm temperature acclimation-related 65 kDa protein (Wap65), fibrinogen, F-type lectin, and alpha-1-antitrypsin. Conclusions: This study highlights the contribution of proteomics for understanding and improving the metabolic compatibility of feeds for marine aquaculture, and opens new perspectives for its monitoring with serological tests.Pubblicat

Effect of modified atmosphere packaging on quality index method (QIM) scores of farmed gilthead seabream (<i>Sparus aurata</i> L.) at low and abused temperatures

A Quality Index Method (QIM) scheme was developed for modified atmosphere packaging (MAP) packed gilthead seabream, and the effect of MAP gas mixtures (60% CO2 and 40% N2; 60% CO2, 30% O2, and 10% N2), temperature (2, 4, and 8 °C), and time of storage on QI scores was assessed. QI scores were crossed with sensory evaluation of cooked fish according to a modified Torry scheme to establish the rejection point. In order to reduce redundant parameters, a principal component analysis was applied on preliminary QIM parameters scores coming from the best performing MAP among those tested. The final QIM scheme consists of 13 parameters and a maximum demerit score of 25. The maximum storage time was found to be 13 d at 4 °C for MAP 60% CO2 and 40% N2. Storage at 2 °C do not substantially improved sensory parameters scores, while storage under temperature abuse (8 °C) accelerated drastically the rate of increase of QI scores and reduced the maximum storage time to 6 d

Proteomic analysis of muscle tissue from gilthead sea bream (<i>Sparus aurata</i>, L.) farmed in offshore floating cages

Characterization of the muscle tissue proteome is key to many aspects of fish aquaculture, encompassing physiology, growth, food safety, seafood authentication and quality, traceability and shelf-life. In this study, a 2D-PAGE-MS study was performed on gilthead sea bream (Sparus aurata, L.) muscle tissue along the production cycle in four offshore floating cage plants and two repopulation lagoons located in different areas of Sardinia, Italy. The aim of this study was to accomplish systematic characterization of the gilthead sea bream muscle proteome, and to gather data about its variability in physiological conditions occurring in both farmed and wild fish. In general, a relatively stable protein expression pattern was observed in farmed sea bream muscle compared to other more dynamic tissue proteomes, such as liver. However, several statistically significant variations in abundance of some proteins and their isoforms were detected, related to growth and environmental factors. Among these, parvalbumins, troponins, and Wap65 showed variations according to fish length and water temperature. Interestingly, the ratio of structural proteins versus glycolytic enzymes was also observed to change during the production cycle, showing an increase with fish length. In order to assess whether the farming conditions were able to induce alterations in the muscle proteome, farmed and wild fish were subjected to a differential proteomics analysis. The data gathered in this study indicate that the protein expression profile of muscle tissue is comparable in wild and maricultured gilthead sea breams of commercial size, supporting the view that farming in offshore floating cages might favor proper muscle tissue development, and therefore enable the production of higher quality fish. In conclusion, this work describes the detailed characterization of the sea bream muscle proteome, and provides a number of insights on its size and environment-related variability