Effects of Yeast Species and Processing on Intestinal Health and Transcriptomic Profiles of Atlantic Salmon (Salmo salar) Fed Soybean Meal-Based Diets in Seawater

publishedVersio

Mapping Energy Expertise: Actors and Topics

The study has been funded by the Stavanger Chamber of Commerce on behalf of a consortium of research-related actors in the Stavanger region,1 and conducted as a collaborative project between the Fridtjof Nansen Institute (FNI) and the Norwegian Institute of International Affairs (NUPI) on behalf of a Stavanger-region consortium of educational and industrial agents. The basic aim has been to provide background information for plans to establish a ‘think tank’ in Norway’s energy capital Stavanger to work on European energy security issues. The main mandate of the project group was to map the leading institutions conducting research on the topic. Research institutions play an important role in the choice of and framing of the security-of-supply problem, and in providing options for policy-makers

Fecal excretion and whole-body retention of macro and micro minerals in Atlantic salmon fed Torula yeast grown on sugar kelp hydrolysate

SIMPLE SUMMARY: Cultivation of seaweed for various purposes has gained more focus in Europe during the last decades. Our study demonstrates the potential of seaweed as a substrate for yeast production, uptake of seaweed minerals into the yeast, and the bioavailability of minerals from this yeast in Atlantic salmon. We show that several minerals, especially the microminerals that are normally supplemented to commercial salmon diets, can be provided by yeast produced on seaweed hydrolysate. ABSTRACT: Yeast is a microbial feed ingredient that can be produced from non-food biomasses. Brown seaweed contains high levels of complex carbohydrates that are not digested to any extent by monogastric animals but can be used as carbon sources for yeast production. The objective of this study was to investigate how minerals originating from brown macroalgae (Saccharina latissima) are incorporated in Cyberlindnera jadinii yeast and to assess the bioavailability of these different minerals as well as their accumulation into different organs of Atlantic salmon. The yeast C. jadinii was produced on a seaweed hydrolysate mixed with a sugar-rich wood hydrolysate in a 9:1 volume ratio and fed to Atlantic salmon (Salmo salar) in two different experiments: a digestibility experiment with 30% dietary inclusion of yeast and a retention experiment with increasing inclusion of yeast (5, 10, and 20%). Seaweed minerals such as zinc (Zn), copper (Cu), iodine (I), manganese (Mn), and cobalt (Co) were incorporated to a high degree in the yeast. The apparent fecal excretion of minerals was similar in both experiments, in general, with low excretion of, I, bromine (Br), and arsenic (As) (ranging from 18.0% to 63.5%) and high excretion of iron (Fe), Cu, Mn, aluminum (Al), cadmium (Cd) and lead (Pb) (ranging from 56.9% to <100%), despite the different fish size and fecal sampling method. High levels of Cu, I, Br, and Co in the yeast resulted in a linear decrease (p < 0.05) in retention of these minerals in salmon fed increasing levels of yeast. Despite increasing amounts of these minerals in the feed, whole-body levels of Cu and Mn remained stable, whereas whole-body levels of Co, somewhat unexpectedly, decreased with increased dietary yeast inclusion. The Cd from the yeast had low bioavailability but was concentrated more in the kidney (0.038 mg kg(−1)) and liver (0.025 mg kg(−1)) than in muscle (0.0009 mg kg(−1)). The given Cd level in fish strengthens the indication that it is safe to feed salmon with up to 20% inclusion of seaweed yeast without exceeding the maximum limit for Cd of 0.05 mg kg(−1) w.w. in fish meat. The level and retention (p < 0.05) of As were lower in the yeast compared to fishmeal. The high level of iodine in S. latissima (3900 mg kg(−1)) was partly transferred to the yeast, and salmon fed increasing levels of yeast displayed a linear increase in whole-body I content (p < 0.05). There is, however, a need for a growth experiment with larger fish to draw any firm conclusions regarding food safety. Overall, this study shows that yeast grown on hydrolyzed seaweed can be a suitable mineral source for Atlantic salmon, especially when diets are low in fishmeal

Obstructive sleep apnea in Norwegian adults with achondroplasia: a population-based study

Background Previous studies have found a high prevalence of obstructive sleep apnea (OSA) in children with achondroplasia, but clinical studies on this complication in adults with achondroplasia are lacking. Objectives This population-based, cross-sectional study investigated the prevalence, severity, and predictive factors of OSA in Norwegian adults with achondroplasia. Methods We collected clinical data on 49 participants. Participants without a preexisting diagnosis of OSA had an overnight sleep registration. OSA was defined as an apnea–hypopnea index (AHI) ≥ 5 plus characteristic clinical symptoms, or AHI ≥ 15. We used the Berlin Questionnaire to assess clinical symptoms of OSA. Results OSA was found in 59% (29/49) of the participants (95% confidence interval 44 to 73%), of whom 59% (17/29) had moderate to severe OSA (AHI ≥ 15), and 48% (14/29) were previously undiagnosed. Variables predictive of OSA were: excessive daytime sleepiness; unrested sleep; loud snoring; observed nocturnal breathing stops; hypertension; age > 40 years; and BMI > 30 kg/m2. Conclusion OSA was highly prevalent in Norwegian adults with achondroplasia, which we believe is representative of this population worldwide. Follow-up of adults with achondroplasia should include assessment of symptoms and signs of OSA, with a low threshold for conducting an overnight sleep registration if findings suggestive of OSA are present

Towards a new marine industry for kelp? : Potential and challenges for culturing algae in Norway

Behovet for bærekraftig produksjon av mat fra havet har aktualisert dyrking av tang og tare. Selv om potensialet for dyrking er stort i Norge er produksjonen på prøvestadiet på grunn av utfordringer knyttet til marked, produksjon, miljø og forvaltning. I denne rapporten har Havforskningsinstituttet, SINTEF og NMBU sammen undersøkt mulighetene for utvikling av en bærekraftig ny havnæring og hva som skal til for å lykkes med lønnsom produksjon av alger. Rapporten kommer også med anbefalinger i forhold til å initiere forskning og innovasjon som kan stimulere til utvikling av en lønnsom og bærekraftig taredyrkingsindustri i Norge.publishedVersio

Mot en ny havnæring for tare? : Muligheter og utfordringer for dyrking av alger i Norge

Behovet for bærekraftig produksjon av mat fra havet har aktualisert dyrking av tang og tare. Selv om potensialet for dyrking er stort i Norge er produksjonen på prøvestadiet på grunn av utfordringer knyttet til marked, produksjon, miljø og forvaltning. I denne rapporten har Havforskningsinstituttet, SINTEF og NMBU sammen undersøkt mulighetene for utvikling av en bærekraftig ny havnæring og hva som skal til for å lykkes med lønnsom produksjon av alger. Rapporten kommer også med anbefalinger i forhold til å initiere forskning og innovasjon som kan stimulere til utvikling av en lønnsom og bærekraftig taredyrkingsindustri i Norge

Microbial Protein Produced from Brown Seaweed and Spruce Wood as a Feed Ingredient

The conversion of nonedible biomass to protein for use in feed is an attractive strategy toward improved sustainability in aquaculture. We have studied the possibility to produce protein-rich yeast Candida utilis on a medium consisting of enzymatically hydrolyzed sulphite-pulped spruce wood, mainly providing glucose, and enzymatically hydrolyzed brown seaweed, supplemented with ammonium sulfate. The results show that this blend constitutes a complete fermentation medium that enables good growth rates and cell yields. Results from a salmon feeding trial showed that the yeast can replace parts of a traditional fishmeal diet without harmful effects, although the apparent protein digestibility coefficient for the yeast was suboptimal. While further optimization of both the fermentation process and downstream processing is needed, the present proof-of-concept study shows a path to the production of microbial protein based on a simple, local and sustainable fermentation medium

Effects of Yeast Species and Processing on Intestinal Health and Transcriptomic Profiles of Atlantic Salmon (Salmo salar) Fed Soybean Meal-Based Diets in Seawater

The objective of the current study was to examine the effects of yeasts on intestinal health and transcriptomic profiles from the distal intestine and spleen tissue of Atlantic salmon fed SBM-based diets in seawater. Cyberlindnera jadinii (CJ) and Wickerhamomyces anomalus (WA) yeasts were heat-inactivated with spray-drying (ICJ and IWA) or autolyzed at 50 °C for 16 h (ACJ and AWA), followed by spray-drying. Six diets were formulated, one based on fishmeal (FM), a challenging diet with 30% soybean meal (SBM) and four other diets containing 30% SBM and 10% of each of the four yeast fractions (i.e., ICJ, ACJ, IWA and AWA). The inclusion of CJ yeasts reduced the loss of enterocyte supranuclear vacuolization and reduced the population of CD8α labeled cells present in the lamina propria of fish fed the SBM diet. The CJ yeasts controlled the inflammatory responses of fish fed SBM through up-regulation of pathways related to wound healing and taurine metabolism. The WA yeasts dampened the inflammatory profile of fish fed SBM through down-regulation of pathways related to toll-like receptor signaling, C-lectin receptor, cytokine receptor and signal transduction. This study suggests that the yeast species, Cyberlindnera jadinii and Wickerhamomyces anomalus are novel high-quality protein sources with health-beneficial effects in terms of reducing inflammation associated with feeding plant-based diets to Atlantic salmon

Effect of yeast species and processing on intestinal microbiota of Atlantic salmon (Salmo salar) fed soybean meal-based diets in seawater

Abstract Background Yeasts are gaining attention as alternative ingredients in aquafeeds. However, the impact of yeast inclusion on modulation of intestinal microbiota of fish fed plant-based ingredients is limited. Thus, the present study investigates the effects of yeast and processing on composition, diversity and predicted metabolic capacity of gut microbiota of Atlantic salmon smolt fed soybean meal (SBM)-based diet. Two yeasts, Cyberlindnera jadinii (CJ) and Wickerhamomyces anomalus (WA), were produced in-house and processed by direct heat-inactivation with spray-drying (ICJ and IWA) or autolyzed at 50 °C for 16 h, followed by spray-drying (ACJ and AWA). In a 42-day feeding experiment, fish were fed one of six diets: a fishmeal (FM)-based diet, a challenging diet with 30% SBM and four other diets containing 30% SBM and 10% of each of the four yeast products (i.e., ICJ, ACJ, IWA and AWA). Microbial profiling of digesta samples was conducted using 16S rRNA gene sequencing, and the predicted metabolic capacities of gut microbiota were determined using genome-scale metabolic models. Results The microbial composition and predicted metabolic capacity of gut microbiota differed between fish fed FM diet and those fed SBM diet. The digesta of fish fed SBM diet was dominated by members of lactic acid bacteria, which was similar to microbial composition in the digesta of fish fed the inactivated yeasts (ICJ and IWA diets). Inclusion of autolyzed yeasts (ACJ and AWA diets) reduced the richness and diversity of gut microbiota in fish. The gut microbiota of fish fed ACJ diet was dominated by the genus Pediococcus and showed a predicted increase in mucin O-glycan degradation compared with the other diets. The gut microbiota of fish fed AWA diet was highly dominated by the family Bacillaceae. Conclusions The present study showed that dietary inclusion of FM and SBM differentially modulate the composition and predicted metabolic capacity of gut microbiota of fish. The inclusion of inactivated yeasts did not alter the modulation caused by SBM-based diet. Fish fed ACJ diet increased relative abundance of Pediococcus, and mucin O-glycan degradation pathway compared with the other diets

Impact of down-stream processing on functional properties of yeasts and the implications on gut health of Atlantic salmon (Salmo salar)

International audienceYeasts are becoming popular as novel ingredients in fish feeds because of their potential to support better growth and concomitantly ensure good fish health. Here, three species of yeasts ( Cyberlindnera jadinii , Blastobotrys adeninivorans and Wickerhamomyces anomalus ), grown on wood sugars and hydrolysates of chicken were subjected to two down-stream processes, either direct heat-inactivation or autolysis, and the feed potential of the resulting yeast preparations was assessed through a feeding trial with Atlantic salmon fry. Histological examination of distal intestine based on widening of lamina propria, showed that autolyzed W. anomalus was effective in alleviating mild intestinal enteritis, while only limited effects were observed for other yeasts. Our results showed that the functionality of yeast in counteracting intestinal enteritis in Atlantic salmon was dependent on both the type of yeast and the down-stream processing method, and demonstrated that C. jadinii and W. anomalus have promising effects on gut health of Atlantic salmon