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Kvalitetskriterier for rensefisk og effekten av stamfiskerernæring - CleanLifeCycle
Full text linkProsjektet hadde som hovedmål å undersøke hvordan stamfiskernæring påvirker fekunditet hos morfisken og kvaliteten på avkommet. Dette skulle undersøkes hos de to rensefiskartene rognkjeks og berggylt, der rognkjeks ble gitt fôr med ulike fettnivå og berggylt ble gitt fôr med ulike nivå av fettsyren arakidonsyre. I rognkjeksforsøket var dødeligheten lavest i lavfett-gruppen, noe som kan ha sammenheng med at de kom sent i gyting. Leverindeksen var lavest hos fisk som fikk det magreste fôret. Hannene sluttet å vokse før hunnene, men var også gyteklare før hunnene. Hunnene i høyfett-gruppen startet gytingen før de to andre gruppene, og avsluttet også tidligere. Dette kan bety at gytestart til en viss grad kan styres med fôrsammensetning. Gonadeindeksen hos hunner på fôr med lavt fett økte først fram mot april, noe som har sammenheng med at de modnet senere enn de to andre behandlingene. Mengde rogn som ble produsert (strøket + gytt i kar) var lavere i gruppen på lavt fett, som trolig skyldes at de kom senere i gyting. Befruktnings- og klekkeprosenter fra forsøkene ved SINTEF Ocean tyder på at kvaliteten på rogna fra fisk på det magreste fôret kan ha bedre kvalitet enn ved de to andre behandlingene. Kvaliteten på rogna i forsøket var ofte dårlig, noe vi mener for en stor del skyldes at fisken gikk på for høy temperatur. Berggylt gyter små (0,75 ± 0,04 mm; gj. snitt ± standard avvik) demersale egg, og et relativt kort fritt embryo stadium der de lever på plommesekken. De må startfôres med små plankton dyr som rotatorier og skipsrur nauplier, og det er relativt høy dødelighet i disse stadiene. Basert på tidligere funn i ernæringsanalyser av rogn fra vill berggylt, bestemte vi oss for å undersøke om gyte- og eggkriterier kunne styrkes med økte mengder arakidonsyre (ARA) i fôret til stamfisken. For å muliggjøre dette studiet utviklet vi et mer robust system for å beregne mengden egg som blir gytt på gytesubstratene som oftest blir benyttet for å samle egg fra berggylt stamfisk. Vi fant liten effekt av ARA på fekunditet, befruktning og klekking. Allikevel var det høy ARA gruppen som produserte egg med tilnærmet lik ARA nivå som det som er funnet i gonadene til vill fisk. ARA hadde en effekt på eggstørrelsen, så vi har en hypotese om at dette kan være en fordel for larvene. Dessverre mistet vi tilgang på nødvendig infrastruktur for å gjennomføre startfôring av larvene p.g.a. Covid-19 relaterte komplikasjoner. Gitt at gonader fra vill fisk har optimale ARA nivå, vil vi anbefale ARA nivå i fôr opp mot 5,6 % av totalt lipid.Kvalitetskriterier for rensefisk og effekten av stamfiskerernæring - CleanLifeCyclepublishedVersio
Fermentation of sugar kelp (Saccharina latissima): exploring the potential of the kelp’s native microbiota as starter culture and the microbiological food safety of fermented products
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A toolkit for facilitating markerless integration of expression cassettes in Komagataella phaffii via CRISPR/Cas9
Full text linkBackground The yeast Komagataella phafi (formerly known as Pichia pastoris) has been widely used for functional expression of recombinant proteins, including plant and animal food proteins. CRISPR/Cas9 genome editing systems can be used for insertion of heterologous genes without the use of selection markers. The study aimed to create a convenient markerless knock-in method for integrating expression cassettes into the chromosome of K. phafi using CRISPR/Cas9 technology. The approach was based on the hierarchical, modular, Golden Gate assembly employing the GoldenPiCS toolkit. Furthermore, the aim was to evaluate the system’s efciency and suitability for producing secreted recombinant food proteins. Results Three Cas9/sgRNA plasmids were constructed, along with corresponding donor helper plasmids con‑ taining homology regions for chromosomal integration via homology-directed repair. The integration efciency of an enhanced green fuorescent protein (eGFP) expression cassette was assessed at three genomic loci (04576, PFK1, and ROX1). The 04576 locus showed the highest integration efciency, while ROX1 had the highest transformation efciency. Whole genome sequencing revealed variable copy numbers of eGFP expression cassettes among clones, corresponding with increasing levels of fuorescence. Furthermore, the system’s applicability for producing recombi‑ nant food proteins was validated by successfully expressing and secreting chicken ovalbumin. This constitutes the frst report of CRISPR/Cas9 applied to produce recombinant chicken ovalbumin. Conclusions The adapted GoldenPiCS toolkit combined with CRISPR/Cas9 technology enabled efcient and precise genome integration in K. phafi. This approach holds promise for expanding the production of high-value recom‑ binant proteins. Future research should focus on optimizing integration sites and improving cloning procedures to enhance the system’s efciency and versatility. Keywords Pichia pastoris, Komagataella phafi, CRISPR/Cas9, Heterologous expression, Golden Gate assembly, Food proteins, Ovalbumin, WGSpublishedVersio
The Local Turn in a Global Sea: Identifying Sustainability Trade-Offs in Regionalized Marine Aquaculture Systems
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Restaurering av tareskog i Norge — Rapport I - Statusrapport
Full text linkDen 14. juni 2024 fattet Stortingets anmodningsvedtak 789: «Stortinget ber regjeringen legge frem en plan og foreslå tiltak for å systematisk restaurere norsk tareskog langs kysten for å bedre det marine miljø.». Vedtaket følges opp av Nærings- og fiskeridepartementet (NFD) i samarbeid med Klima- og Miljødepartementet (KLD). Oppdraget er gitt til Havforskningsinstituttet i tildelingsbrevet for 2025. Det skal løses i samarbeid med Fiskeridirektoratet.Restaurering av tareskog i Norge — Rapport I - StatusrapportpublishedVersio
Effect of eicosapentaenoic acid on innate immune responses in Atlantic salmon cells infected with infectious salmon anemia virus
Full text linkAquaculture is one of the world's fastest-growing sectors in food production but with multiple challenges related to animal handling and infections. The disease caused by infectious salmon anemia virus (ISAV) leads to outbreaks of local epidemics, reducing animal welfare, and causing significant economic losses. The composition of feed has shifted from marine ingredients such as fish oil and fish meal towards a more plant-based diet causing reduced levels of eicosapentaenoic acid (EPA). The aim of this study was to investigate whether low or high levels of EPA affect the expression of genes related to the innate immune response 48 h after infection with ISAV. The study includes seven experimental groups: ± ISAV and various levels of EPA up to 200 µM. Analysis of RNA sequencing data showed that more than 3000 genes were affected by ISAV alone (without additional EPA). In cells with increasing levels of EPA, more than 2500 additional genes were differentially expressed. This indicates that high levels of EPA concentration have an independent effect on gene expression in virus-infected cells, not observed at lower levels of EPA. Analyses of enriched biological processes and molecular functions (GO and KEGG analysis) revealed that EPA had a limited impact on the innate immune system alone, but that many processes were affected by EPA when cells were virus infected. Several biological pathways were affected, including protein synthesis (ribosomal transcripts), peroxisome proliferator activated receptor (PPAR) signaling, and ferroptosis. Cells exposed to both increasing concentrations of EPA and virus displayed gene expression patterns indicating increased formation of oxygen radicals and that cell death via ferroptosis was activated. This gene expression pattern was not observed during infection at low EPA levels or when Atlantic salmon kidney (ASK) cells were exposed to the highest EPA level (200 μM) without virus infection. Cell death via ferroptosis may therefore be a mechanism for controlled cell death and thus reduction of virus replication when there are enough polyunsaturated fatty acids (PUFAs) in the membrane.publishedVersio
Side-Stream Based Marine Solubles From Atlantic Cod (Gadus morhua) Modulate Appetite and Dietary Nutrient Utilization in Atlantic Salmon (Salmo salar L.) and can Replace Fish Meal
Full text linkWhitefish fisheries’ side-stream biomass is an abundant underutilized resource that can be valorized to benefit future aquaculture sustainability. Four novel ingredients based on side-streams from Atlantic cod (Gadus morhua) fileting were produced. FM-hb, a fish meal (FM), and FPH-hb, a fish protein hydrolysate based on heads (h) and backbones (b); FM-hbg, a FM based on heads, backbones, and viscera/guts (g); and FPC-g, a fish protein concentrate based on viscera preserved in formic acid. Four diets were prepared containing one of the ingredients replacing 50% of the dietary FM protein, in addition to a positive (FM10) and a negative (FM5) control. The six diets were fed to triplicate tanks with Atlantic salmon (Salmo salar L.; 113Æ 1 g) over 8 weeks. Besides general performance, gut and brain gene expression for selected hormones and key neuropeptides involved in the control of appetite and digestive processes were studied during feeding and postprandial, and possible reference levels for Atlantic salmon were established. All side-stream-added diets performed well, with no significant differences in performance and biometrics between the treatments. Some gene expression differences were observed, but no well-defined patterns emerged supporting clear dietary effects related to digestive performance or appetite. However, in the brain, a short-time upregulation of agouti-related protein-1 (agrp1), corresponded to higher cumulative feed intake (FI) for the FM10 diet supporting notions that this may be a candidate biomarker for appetite in salmon. Expression of stomach ghrelin-1 (ghrl1) was higher than ghrelin-2 (ghrl2) and membrane-bound O-acyltransferase domaincontaining 4 (mboat4), and midgut peptide YYa-2 (pyya2) and glucagon-a (gcga) were higher than peptide YYb-1 (pyyb1). A comparison showed that midgut peptide YYa-1 (pyya1), pyya2, and gcga expressions were higher than in the hindgut, which is opposite of what is found in mammals. In conclusion, this study shows that sustainable side-stream raw materials with different characteristics can partly replace high-quality commercial FMs giving similar performance.publishedVersio
Interaction between dietary saturated fatty acids and cholesterol on mineral and fatty acid availability and postprandial lipids absorption kinetics in Atlantic salmon (Salmo salar)
Full text linkAtlantic salmon (Salmo salar) with an initial weight of approximately 160 g were fed with one of four experimental diets containing low / high levels of saturated fatty acids (SFA, 10 % vs. 24 % of total fatty acid) / cholesterol (CHO, 200 vs. 2400 mg kg−1) in a 2 × 2 design, lasting for 3 months. Plasma samples were collected at 7 postprandial time points (0 h–35.5 h) after 50 days of feeding, and fish were sampled at the end of the trial. Results showed that the increased SFA level in the feed significantly increased the whole-body selenium and iron concentrations. However, whole-body zinc status was neither affected by dietary SFA nor CHO. Additionally, increased SFA level in feed significantly increased the postprandial plasma CHO, low density lipoprotein (LDL) and total protein levels. Also, increased CHO level in feed increased the postprandial plasma astaxanthin, CHO, high density lipoprotein (HDL) and LDL levels. However, analyzed markers related to intestinal triacylglycerol transport were not affected by dietary SFA. Due to dramatic reductions of SFA and CHO in plant-based feed, understanding their nutritional function in Salmo salar is important for the aquaculture industry.publishedVersio
Non-contact interactance NIR spectroscopy for estimating TSS and sensory sweetness in conveyor-belt transported cherry tomatoes (Lycopersicon esculentum ’Piccolo’)
No full textSweetness in tomatoes is a crucial quality feature, especially for high-cost varieties. Without efficient measurements, producers cannot guarantee sweetness, which may lead to low repurchase rates and increased food waste. In this article we report how total soluble solids (TSS), a measure for total sugar content, can be measured in cherry tomatoes using non-contact near-infrared (NIR) interactance spectroscopy. A prototype system working in the wavelength range 760–1080 nm was tested and compared with a commercial handheld NIR reflection instrument operating in the range of 909–1676 nm. The instruments were calibrated using data collected from 200 tomatoes and tested on 5 independent sets harvested over the next 14 months, a total of 611 single tomatoes and 22 tomato trusses. TSS for single tomatoes was in the range 5.3–14 %. NIR interaction obtained typical standard errors of prediction in the range 0.38–0.52 %, significantly lower (p < 0.05) compared to NIR reflection (0.70–0.98 %). Approximately the same accuracy was obtained by interaction measurements on tomatoes moving on a conveyor belt, both in lab (0.47–0.53 %) and in industry (0.39 %). Whole tomato trusses were measured in movement, and TSS could successfully be measured in each tomato on the truss. Three of the test sets were subjected to sensory analysis performed by a trained panel of 10 assessors, revealing high correlations (0.88 – 0.99) between sensory sweetness and NIR estimated TSS. The results demonstrate that a carefully designed NIR interaction instrument can be used for rapid and non-contact monitoring and sorting of cherry tomatoes according to sweetness.publishedVersio
