A Comparative Study of Collagen Proteins in Skin, Bones, and Guts of Atlantic Salmon (Salmo salar L.) and Atlantic Cod (Gadus morhua)

The contents and distribution of different collagen types in bones, skins, and guts of salmon and cod were assessed by chemical and mass spectroscopic methods. The highest levels of collagen were found in the skin (89–98%), followed by the bones (79–89%), and the guts (25–36%). A variety of different collagen α-chain proteins were detected in the assessed tissues, with proteins from 12 to 6 different collagen types quantified in salmon and cod, respectively. The less well-known collagen IV was found in significant levels in all tissues, and the most diverse collagen composition was found in the bones.A Comparative Study of Collagen Proteins in Skin, Bones, and Guts of Atlantic Salmon (Salmo salar L.) and Atlantic Cod (Gadus morhua)publishedVersio

Methionine deficiency does not increase polyamine turnover through depletion of hepatic S-adenosylmethionine in juvenile Atlantic salmon

During the last few decades, plant protein ingredients such as soya proteins have replaced fishmeal in the diets of aquacultured species. This may affect the requirement and metabolism of methionine as soya contains less methionine compared with fishmeal. To assess whether methionine limitation affects decarboxylated S-adenosylmethionine availability and polyamine status, in the present study, juvenile Atlantic salmon were fed a methionine-deficient plant protein-based diet or the same diet supplemented with dl-methionine for 8 weeks. The test diets were compared with a fishmeal-based control diet to assess their effects on the growth performance of fish. Methionine limitation reduced growth and protein accretion, but when fish were fed the dl-methionine-supplemented diet their growth and protein accretion equalled those of fish fed the fishmeal-based control diet. Methionine limitation reduced free methionine concentrations in the plasma and muscle, while those in the liver were not affected. S-adenosylmethionine (SAM) concentrations were higher in the liver of fish fed the methionine-deficient diet, while S-adenosylhomocysteine concentrations were not affected. Putrescine concentrations were higher and spermine concentrations were lower in the liver of fish fed the methionine-deficient diet, while the gene expression of SAM decarboxylase (SAMdc) and the rate-limiting enzyme of polyamine synthesis ornithine decarboxylase (ODC) was not affected. Polyamine turnover, as assessed by spermine/spermidine acetyltransferase (SSAT) abundance, activity and gene expression, was not affected by treatment. However, the gene expression of the cytokine TNF-α increased in fish fed the methionine-deficient diet, indicative of stressful conditions in the liver. Even though taurine concentrations in the liver were not affected by treatment, methionine and taurine concentrations in muscle decreased due to methionine deficiency. Concomitantly, liver phospholipid and cholesterol concentrations were reduced, while NEFA concentrations were elevated. In conclusion, methionine deficiency did not increase polyamine turnover through depletion of hepatic SAM, as assessed by SSAT activity and abundance.publishedVersio

Identification of proteins related to the stress response in Enterococcus faecalis V583 caused by bovine bile

<p>Abstract</p> <p>Background</p> <p><it>Enterococcus faecalis </it>is an opportunistic pathogen and one of the most important causes of hospital infections. Bile acids are a major stress factor bacteria have to cope with in order to colonize and survive in the gastro-intestinal tract. The aim of this study was to investigate the effects of bile acids on the intracellular proteome of <it>E. faecalis </it>V583.</p> <p>Results</p> <p>The proteomes of cells challenged with 1% bile were analyzed after 20 - 120 minutes exposure, using 2D gel electrophoresis and mass spectrometry. Among the approximately 500 observed proteins, 53 unique proteins were found to be regulated in response to bile and were identified with mass spectrometry. The identified proteins belonged to nine different functional classes, including fatty acid- and phospholipid-biosynthesis, energy metabolism, and transport and binding. Proteins involved in fatty acid and phospholipid biosynthesis pathways were clearly overrepresented among the identified proteins and all were down-regulated upon exposure to bile. The proteome data correlated reasonably well with data from previous transcriptome experiments done under the same conditions, but several differences were observed.</p> <p>Conclusion</p> <p>The results provide an overview of potentially important proteins that <it>E. faecalis </it>V583 needs to regulate in order to survive and adapt to a bile-rich environment, among which are several proteins involved in fatty acid and phospholipid biosynthesis pathways. In addition, this study reveals several hypothetical proteins, which are both abundant and clearly regulated and thus stand out as targets for future studies on bile stress.</p

Dietary intake of micronized avian eggshell membrane in aged mice reduces circulating inflammatory markers, increases microbiota diversity, and attenuates skeletal muscle aging

Introduction: Avian eggshell membrane (ESM) is a complex extracellular matrix comprising collagens, glycoproteins, proteoglycans, and hyaluronic acid. We have previously demonstrated that ESM possesses anti-inflammatory properties in vitro and regulates wound healing processes in vivo. The present study aimed to investigate if oral intake of micronized ESM could attenuate skeletal muscle aging associated with beneficial alterations in gut microbiota profile and reduced inflammation. Methods: Elderly male C57BL/6 mice were fed an AIN93G diet supplemented with 0, 0.1, 1, or 8% ESM. Young mice were used as reference. The digestibility of ESM was investigated using the static in vitro digestion model INFOGEST for older people and adults, and the gut microbiota profile was analyzed in mice. In addition, we performed a small-scale pre-clinical human study with healthy home-dwelling elderly (>70 years) who received capsules with a placebo or 500 mg ESM every day for 4 weeks and studied the effect on circulating inflammatory markers. Results and discussion: Intake of ESM in elderly mice impacted and attenuated several well-known hallmarks of aging, such as a reduction in the number of skeletal muscle fibers, the appearance of centronucleated fibers, a decrease in type IIa/IIx fiber type proportion, reduced gene expression of satellite cell markers Sdc3 and Pax7 and increased gene expression of the muscle atrophy marker Fbxo32. Similarly, a transition toward the phenotypic characteristics of young mice was observed for several proteins involved in cellular processes and metabolism. The digestibility of ESM was poor, especially for the elderly condition. Furthermore, our experiments showed that mice fed with 8% ESM had increased gut microbiota diversity and altered microbiota composition compared with the other groups. ESM in the diet also lowered the expression of the inflammation marker TNFA in mice and in vitro in THP-1 macrophages. In the human study, intake of ESM capsules significantly reduced the inflammatory marker CRP. Altogether, our results suggest that ESM, a natural extracellular biomaterial, may be attractive as a nutraceutical candidate with a possible effect on skeletal muscle aging possibly through its immunomodulating effect or gut microbiota.publishedVersio

An opinion paper: emphasis on white muscle development and growth to improve farmed fish flesh quality

Due to rapid depletion of wild stocks, the necessity to cultivate fish is eminent. Current fish farming practices seek to improve flesh quality. The notion that white muscles are the main target of the fishing industry is emphasized. A novel approach is suggested based on the development of white muscles in wild fish from eggs to adults. A compilation of facts about white muscle structure, function and ontogeny is followed by an account of the changes in swimming behaviour and performance related to the use of white muscle during growth from larva to adult. Ecological data narrate early swimming performance with white muscle development and growth, unveiling some of the important natural selection factors eliminating weak swimmers and poor growers from the breeding stock. A comparison between fish culture practise and natural conditions reveals fundamental differences. New approaches following wild breeding processes promise several important advantages regarding the quality of white muscle

The role of extracellular matrix components in pin bone attachments during storage—a comparison between farmed Atlantic salmon (Salmo salar) and cod (Gadus morhua L.)

Pin bones represent a major problem for processing and quality of fish products. Development of methods of removal requires better knowledge of the pin bones’ attachment to the muscle and structures involved in the breakdown during loosening. In this study, pin bones from cod and salmon were dissected from fish fillets after slaughter or storage on ice for 5 days, and thereafter analysed with molecular methods, which revealed major differences between these species before and after storage. The connective tissue (CT) attaches the pin bone to the muscle in cod, while the pin bones in salmon are embedded in adipose tissue. Collagens, elastin, lectin-binding proteins and glycosaminoglycans (GAGs) are all components of the attachment site, and this differ between salmon and cod, resulting in a CT in cod that is more resistant to enzymatic degradation compared to the CT in salmon. Structural differences are reflected in the composition of transcriptome. Microarray analysis comparing the attachment sites of the pin bones with a reference muscle sample showed limited differences in salmon. In cod, on the other hand, the variances were substantial, and the gene expression profiles suggested difference in myofibre structure, metabolism and cell processes between the pin bone attachment site and the reference muscle. Degradation of the connective tissue occurs closest to the pin bones and not in the neighbouring tissue, which was shown using light microscopy. This study shows that the attachment of the pin bones in cod and salmon is different; therefore, the development of methods for removal should be tailored to each individual species. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s10695-016-0309-0) contains supplementary material, which is available to authorized users

The application of omics in ruminant production: a review in the tropical and sub-tropical animal production context

The demand for animal products (e.g. dairy and beef) in tropical regions is expected to increase in parallel with the public demand for sustainable practices, due to factors such as population growth and climate change. The necessity to increase animal production output must be achieved with better management and production technologies. For this to happen, novel research methodologies, animal selection and postgenomic tools play a pivotal role. Indeed, improving breeder selection programs, the quality of meat and dairy products as well as animal health will contribute to higher sustainability and productivity. This would surely benefit regions where resource quality and quantity are increasingly unstable, and research is still very incipient, which is the case of many regions in the tropics. The purpose of this review is to demonstrate how omics-based approaches play a major role in animal science, particularly concerning ruminant production systems and research associated to the tropics and developing countriesinfo:eu-repo/semantics/acceptedVersio

Låssetting av sommermakrell. Delrapport

Dette er en delrapport i FHF-prosjektet «Låssetting av sommermakrell» fase 2, der en kvalitetsbedømmelsen etter låssettingsperioden er blitt utført. Metodene som er blitt benyttet til kvalitetsbedømmelse er instrumentell måling av tekstur og histologi. Fisken som er blitt vurdert er fra låssetting serien beskrevet i fase 1 i prosjektet. Det ble målt tekstur på fileter fra fisk etter ulike tidspunkter av låssetting (dag 0, dag 1, dag 3, dag 7, dag 14, dag 25 og dag 37). Teksturanalysene viste en signifikant økning i fasthet etter dag 3 med låssetting, og med høyeste verdier i slutten av låssettingsperioden. På bakgrunn av de histologiske undersøkelsene ser det ut som om musklene i den første perioden etter låssettingen (dvs. etter 3 og 14 dagers låssetting) går inn i en noe unormal tilstand, med både nedbryting og krymping av muskelfibre, samt mindre tettpakkede muskelfibre. Etter 37 dagers låssetting ser det ut som om musklene nærmer seg en normaltilstand igjen (dvs. lik kontrollgruppen og dag 0 låssettingsgruppen), men med noe større muskelfibre. Parametere som størrelse på fisk, muskelfiberstørrelse, og mengde bindevev er kjent å kunne gi fastere tekstur. Flere analyser i forhold til disse parameterne vil være nødvendig for endelig kunne forklare mulig årsak til økte teksturverdier utover i låssettingsperioden på makrellfilet

Can postmortem proteolysis explain tenderness differences in various bovine muscles?

This study investigated the relationship between postmortem proteolysis, muscle pH decline, sarcomere length (SL), intramuscular fat (IMF) and Warner-Bratzler shear force (WBSF) in four bovine muscles (biceps femoris (BF), infraspinatus (IS), longissimus lumborum (LL), psoas major (PM). The WBSF was low in BF, IS and PM, while LL had a higher value (P<0.001), but still considered as tender. The PM had fastest pH decline (P<0.001), ultimate pH was lowest in LL and PM and highest for IS (P<0.001), sarcomeres were longest for PM and shortest for BF and LL (P<0.001), while IS and PM had more IMF than BF and LL (P=0.038). Troponin T degradation was similar in all muscles after 2d postmortem, however after 13d LL had more degradation than IS (P=0.003). The MMP-2 activity increased during storage (P=0.001), while IS had less activity than the other muscles (P=0.022). Although the variation in proteolytic activity could not explain the variation in WBSF, the study provides useful knowledge for the meat industry for optimising processing and storage procedures for different beef muscles.Can postmortem proteolysis explain tenderness differences in various bovine muscles?submittedVersio

Predicting post-mortem meat quality in porcine longissimus lumborum using Raman, near infrared and fluorescence spectroscopy

Spectroscopic techniques can provide valuable information about post-mortem meat quality. In the current study, Raman, NIR and fluorescence spectroscopy was used to analyze pH, drip loss and intramuscular fat in pork longissimus lumborum (n = 122) at 4–5 days post-mortem. Results were promising for partial least squares regression (PLSR) from Raman spectroscopy, giving coefficients of determination from cross validation (rcv2) ranging from 0.49 to 0.73 for all attributes examined. Important regions in the PLSR models from Raman spectroscopy were attributed to changes in concentrations of post-mortem metabolites and modifications of protein secondary structure. Near infrared and fluorescence spectroscopy showed limited ability to analyze quality, with rcv2 ranging from 0.06 to 0.57 and 0.04 to 0.18, respectively. This study encourages further research on the subject of Raman spectroscopy as a technique for meat quality analysis.submittedVersio