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| 2. |
- Bergman, Kristina, et al.
(författare)
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Environmental and biodiversity performance of a novel single cell protein for rainbow trout feed
- 2024
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Ingår i: Science of the Total Environment. - : Elsevier B.V.. - 0048-9697 .- 1879-1026. ; 907
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Tidskriftsartikel (refereegranskat)abstract
- Seafood has an important role to play to achieve a sustainable food system that provides healthy food to a growing world population. Future seafood production will be increasingly reliant on aquaculture where feed innovation is essential to reduce environmental impacts and minimize feed and food competition. This study aimed to investigate whether a novel single cell protein feed ingredient based on Paecilomyces variotii grown on a side stream from the forest industry could improve environmental sustainability of farmed rainbow trout (Oncorhynchus mykiss) by replacing the soy protein concentrate used today. A Life Cycle Assessment including commonly addressed impacts but also the rarely assessed biodiversity impacts was performed. Furthermore, feeding trials were included for potential effects on fish growth, i.e., an assessment of the environmental impacts for the functional unit ‘kg feed required to produce 1 kg live-weight rainbow trout’. Results showed that the best experimental diet containing P. variotii performed 16–73 % better than the control diet containing soy protein concentrate in all impact categories except for energy demand (21 % higher impact). The largest environmental benefits from replacing soy protein with P. variotii in rainbow trout diets was a 73 % reduction of impact on biodiversity and halved greenhouse gas emissions. The findings have high relevance for the aquaculture industry as the production scale and feed composition was comparable to commercial operations and because the effect on fish growth from inclusion of the novel ingredient in a complete diet was evaluated. The results on biodiversity loss from land use change and exploitation through fishing suggest that fishery can dominate impacts and exclusion thereof can greatly underestimate biodiversity impact. Finally, a novel feed ingredient grown on side streams from the forest industry has potential to add to food security through decreasing the dependence on increasingly scarce agricultural land resources.
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| 3. |
- Ewald, Nils, et al.
(författare)
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Fatty acid composition of black soldier fly larvae (Hermetia illucens) - Possibilities and limitations for modification through diet
- 2020
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Ingår i: Waste Management. - : Elsevier BV. - 0956-053X .- 1879-2456. ; 102, s. 40-47
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Tidskriftsartikel (refereegranskat)abstract
- Black soldier fly larvae (Hermetia illucens; BSFL) can convert organic wastes into a nutrient-rich biomass suitable in animal feed, which could be a way to achieve more sustainable production of food. However, little is known about how the diet fed to BSFL affects their nutritional value, especially their fatty acid composition. In this study, BSFL were fed 11 diets based on four different organic waste sources (mussels, bread, fish and food waste). Fatty acid and proximate composition (dry matter, crude fat, crude protein and ash) were analysed in the diets, in two-week-old larvae and substrate residues. Larval weight, survival and feed conversion were also recorded. The diet was found to affect all parameters investigated. Irrespective of diet, the larval fat consisted mainly of lauric acid and other saturated fatty acids and these were found to be synthesised by the larvae. However, both the fatty acid composition of the substrate, and the larval weight were found to affect the fatty acid profile of the larvae. In general, larvae with a higher weight contained a higher percentage of saturated fatty acids and a lower percentage of unsaturated fatty acids, such as eicosapentaenoic (EPA) and docosahexaenoic acid (DHA). It was concluded that the possibilities to tailor the fatty acid composition of the BSFL through the diet are limited; thus, the BSFL fat may not be suitable to replace fish oil, but has potential of inclusion in other food, feed and fuel products. (C) 2019 The Authors. Published by Elsevier Ltd.
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| 4. |
- Hinchcliffe, James, 1992, et al.
(författare)
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Comparative survival and growth performance of European lobster Homarus gammarus post-larva reared on novel feeds
- 2020
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Ingår i: Aquaculture Research. - : Hindawi Limited. - 1355-557X .- 1365-2109. ; 51:1, s. 102-113
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Tidskriftsartikel (refereegranskat)abstract
- One approach to ongrow juvenile European lobster, Homarus gammarus, is to utilize land based rearing systems, incorporating automated feeding, individual culture and provision of stable pelleted feeds, preferably using sustainable ingredients. We initiated three feeding experiments to investigate the general suitability of ingredients produced from seafood by-products as novel feeds for H. gammarus, in terms of promoting survival, development and growth of post-larval lobsters from post-larvae (PL) stage IV to the first juvenile stage (stage V). The first experiment was designed to screen an array of candidate, locally produced, novel protein sources on growth performance parameters. This initial experiment revealed that PL reared on a raw (i.e. wet, unprocessed shrimp) feed used as a reference showed superior performance to those reared on experimental feeds containing fishmeal, herring protein isolate or mussel meal; however, a novel type of shrimp meal, produced by flocculation from waste water, promoted the best PL performance of any experimental feed. A second experiment was designed to test the effect of drying method and to optimize the form of a wet shrimp reference feed used by lobster hatcheries. This showed that the performance of PL reared on experimental freeze-dried shrimp feed was not significantly different to those reared on the wet, unprocessed shrimp used as a reference feed. However, lobsters offered experimental oven-dried shrimp feed (with or without an immune supplement) resulted in significantly lower survival or growth performance. A third and final experiment was designed in an attempt to improve a candidate herring-based protein source, by supplementing with nutrients found in shrimp. However, the results showed that PL reared on the wet reference shrimp feed still showed superior growth and survival than those reared on a herring feed alone, or supplemented with additives found in shrimp meal (either glucosamine, astaxanthin or both supplements combined). The high survival and growth, low incidence of moulting problems and high availability of waste shrimp material, suggest that non-heat-treated shrimp products are a promising feed ingredient for post-larval European lobsters.
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| 5. |
- Hultberg, Malin, et al.
(författare)
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Adding benefit to wetlands : valorization of harvested common reed through mushroom production
- 2018
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Ingår i: Science of the Total Environment. - 0048-9697 .- 1879-1026. ; 637-638, s. 1395-1399
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Tidskriftsartikel (refereegranskat)abstract
- Wetlands have been successfully implemented as water purification systems for removal of plant nutrients and can play a significant role in nutrient recycling, depending on use of the harvested biomass. In a constructed wetland in southern Sweden examined in this study, assimilation of plant nutrients in wetland biomass corresponded to 234 kg/ha nitrogen, 22.8 kg/ha phosphorus, and 158 kg/ha potassium in the study year (2016). The harvested biomass, composed exclusively of common reed, was evaluated as a substrate for production of oyster mushrooms, one of the most widely produced edible mushrooms in the world. The biological efficiency of the substrate was 138 ± 10%, corresponding to production of 1.4 kg mushrooms (fresh weight) based on 1 kg reed (dry weight). The fruiting bodies had high quality, with total protein concentration 18.3 ± 2.8% and very low levels of contaminating heavy metals. Thus, nutrient assimilation in wetland biomass not only decreases the risk of eutrophication in recipient waters, but can be utilized for direct production of high-quality food. The biomass remaining after mushroom production, composed of mycelium and partly degraded wetland biomass, has potential for use in ruminant feed, i.e., as roughage.
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| 6. |
- Hultberg, Malin, et al.
(författare)
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Adding benefit to wetlands - Valorization of harvested common reed through mushroom production
- 2018
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Ingår i: Science of the Total Environment. - : Elsevier BV. - 0048-9697 .- 1879-1026. ; 637-638, s. 1395-1399
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Tidskriftsartikel (refereegranskat)abstract
- Wetlands have been successfully implemented as water purification systems for removal of plant nutrients and can play a significant role in nutrient recycling, depending on use of the harvested biomass. In a constructed wetland in southern Sweden examined in this study, assimilation of plant nutrients in wetland biomass corresponded to 234 kg/ha nitrogen, 22.8 kg/ha phosphorus, and 158 kg/ha potassium in the study year (2016). The harvested biomass, composed exclusively of common reed, was evaluated as a substrate for production of oyster mushrooms, one of the most widely produced edible mushrooms in the world. The biological efficiency of the substrate was 138 +/- 10%, corresponding to production of 1.4 kg mushrooms (fresh weight) based on 1 kg reed (dry weight). The fruiting bodies had high quality, with total protein concentration 18.3 +/- 2.8% and very low levels of contaminating heavy metals. Thus, nutrient assimilation in wetland biomass not only decreases the risk of eutrophication in recipient waters, but can be utilized for direct production of high-quality food. The biomass remaining after mushroom production, composed of mycelium and partly degraded wetland biomass, has potential for use in ruminant feed, i.e., as roughage. (C) 2018 Elsevier B.V. All rights reserved.
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| 7. |
- Huyben, David, et al.
(författare)
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Effects of dietary inclusion of the yeasts Saccharomyces cerevisiae and Wickerhamomyces anomalus on gut microbiota of rainbow trout
- 2017
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Ingår i: Aquaculture. - : Elsevier BV. - 0044-8486 .- 1873-5622. ; 473, s. 528-537
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Tidskriftsartikel (refereegranskat)abstract
- Rainbow trout (Oncorhynchus mykiss) were fed for 10 weeks on a diet containing either 30% fish meal (FM) or with 20, 40 and 60% replacement of fish meal protein with Saccharomyces cerevisiae (SC) or a mixture of Wickerhamomyces anomalus and S. cerevisiae(WA). Luminal contents and mucosal tissue from the distal intestine were collected and analysed for yeast and bacterial loads by agar plating. Diversity and abundance were determined by sequencing of amplicons generated from the 26S rRNA (yeast) and 16S rRNA (bacteria) genes. In addition, the diets were analysed before and after feed extrusion to determine the viability and composition of the yeasts ingested by the fish. After extrusion, 9-10 log cells g(-1) of yeast were still intact in the SC and WA diets, but culturable yeast showed log-reductions of 5-7 CFU g(-1). For yeasts isolated from the gut contents, 81-96% of colonies consisted of Debaryomyces hansenii, with few or no colonies of S. cerevisiae or W. anomalus despite their high inclusion rate in the diets. Characterisation of gut bacteria using Illumina MiSeq showed that 70 and 19% of sequences were classified to the phyla Firmicutes and Proteobacteria, specifically sequences identified as Leuconostocaceae, Lactobacillaceae and Photobacterium. Compared with the FM diet, the WA40 diet reduced bacterial diversity, whereas the WA60 diet increased the abundance of the pathogenic yeast Candida albicans and reduced lactic acid bacteria in the gut. Overall, 40 and 60% replacement of fish meal protein with a mixture of W. anomalus and S. cerevisiae significantly altered the gut microbiota of rainbow trout, while 20% replacement and diets with only S. cerevisiae had little or no effect. (C) 2017 Elsevier B.V. All rights reserved.
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| 8. |
- Huyben, David, et al.
(författare)
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Effects of dietary yeast inclusion and acute stress on post-prandial whole blood profiles of dorsal aorta-cannulated rainbow trout
- 2017
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Ingår i: Fish Physiology and Biochemistry. - : Springer Science and Business Media LLC. - 0920-1742 .- 1573-5168. ; 43, s. 421-434
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Tidskriftsartikel (refereegranskat)abstract
- Yeast is a potential alternative to fish meal in diets for farmed fish, yet replacing more than 50 % of fish meal results in reduced fish growth. In a 4-week experiment, 15 rainbow trout (Oncorhynchus mykiss) were cannulated and fed three diets each week: 30 % fish meal as a control (FM); 60 % replacement of fish meal protein, on a digestible basis, with Saccharomyces cerevisiae (SC); and 60 % replacement with Wickerhamomyces anomalus and S. cerevisiae mix (WA). Blood was collected at 0, 3, 6, 12 and 24 h after feeding. In the final week, fish were exposed to a 1-min netting stressor to evaluate possible diet-stress interactions. Significant increases in pH, TCO2, HCO3 and base excess were found after fish were fed the SC and WA diets compared with FM, which elevated blood alkaline tides. Yeast ingredients had lower buffering capacity and ash content than fish meal, which explained the increase in alkaline tides. In addition, fish fed the WA diet had significantly reduced erythrocyte area and fish fed SC and WA diets had increased mean corpuscular haemoglobin levels, indicating haemolytic anaemia. Higher levels of nucleic acid in yeast-based diets and potentially higher production of reactive oxygen species were suspected of damaging haemoglobin, which require replacement by smaller immature erythrocytes. Acute stress caused the expected rise in cortisol and glucose levels, but no interaction with diet was found. These results show that replacing 60 % of fish meal protein with yeasts can induce haemolytic anaemia in rainbow trout, which may limit yeast inclusion in diets for farmed fish.
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| 9. |
- Huyben, David, et al.
(författare)
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Effects of dietary yeast inclusion and acute stress on postprandial plasma free amino acid profiles of dorsal aorta-cannulated rainbow trout
- 2018
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Ingår i: Aquaculture Nutrition. - : Hindawi Limited. - 1353-5773 .- 1365-2095. ; 24, s. 236-246
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Tidskriftsartikel (refereegranskat)abstract
- In a 4-week experiment, 15 cannulated rainbow trout were fed three diets based on fish meal (FM), Saccharomyces cerevisiae yeast (SC) and Wickerhamomyces anomalus and S.cerevisiae yeast mix (WA). Fish were fed daily, and blood samples were collected on day 7 of each week at 0, 3, 6, 12 and 24hr after feeding. In the final week, fish were exposed to a 1-min netting stressor. All essential and non-essential plasma amino acid levels except methionine were similar between fish fed diets FM, SC and WA. Plasma methionine and sarcosine were significantly higher in fish fed diets SC and WA, possibly due to the crystalline methionine level, form or feeding regime. Hydroxy-proline and 3-methyl-histidine were higher in fish fed diet FM, which can be explained by the higher levels present in fish meal compared with yeast. In stressed fish, there were no dietary effects on plasma amino acid levels, but significant increases in taurine and cystathionine were found in stressed compared with unstressed fish. These results demonstrate that yeast-based diets produce similar plasma amino acid profiles to fish meal and suggest that yeast may be a suitable fish meal replacement in diets for rainbow trout.
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| 10. |
- Huyben, David, et al.
(författare)
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Effects of feeding yeasts, Saccharomyces cerevisiae and Wickerhamomyces anomalus, on gut microbiota of rainbow trout
- 2016
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Introduction Single cell proteins, such as yeasts, are an ideal feed alternative to plant and fish meals as they do not compete as food for humans. Previous studies have fed live yeast, such asSaccharomyces cerevisiae, in cold pelleted diets to farmed fish in order to increase beneficial microbiota in the gut (Gatesoupe, 2007). However, commercial salmonid diets are typically extruded at high temperatures, which can inactivate yeasts and reduce their effects on gut microbiota. In addition, previous studies have used culture-based methods to determine gut microbiota, while the development of next generation sequencing has improved identification of unculturable microbiota. The objective of this study was to determine the effect of feeding yeasts,S. cerevisiae and Wickerhamomyces anomalus, on microbiota in the distal intestine of rainbow trout (Oncorhynchus mykiss). Materials and methods A diet of fish meal (FM) was used as a control against yeast diets that replaced 20, 40 and 60% of fish meal (digestible protein basis) with either S. cerevisiae(SC) orW.anomalus/S. cerevisiaemix (WA; Jästbolaget AB, Sweden). Diets were extruded at 120-130oC and later fed to triplicate tanks of 35 rainbow trout for 10 weeks. Afterwards, content and mucosa from the distal intestine of 3 fish per tank were collected. Ingredients, diets and gut samples were plated on yeast-peptone-D-glucose, then 26S rDNA were PCR-amplified and sequenced to determine live yeast counts and taxa. Diets and yeast ingredients were further examined microscopically to determine cell counts of yeast. For gut bacteria, 16S rDNA were PCR-amplified, barcoded and next generation sequenced using Illumina platform (SciLifeLab AB, Sweden). Significant differences (p<0.05) between diets were determined using ANOVA and ANOSIM methods. Results The yeast ingredients,S. cerevisiaeor W. anomalus/S. cerevisiae mix, contained between 9-10 log cfu g-1and SC and WA diets contained 7-8 log cfu g-1before extrusion. After extrusion, all diets had over 4-log reduction in cfu g-1(cultured yeast), however 7-8 log cells g-1of yeast were still viable. Diets of SC and WA contained between 96-100%S. cerevisiaeand 0-20%W. anomalus.After 10 weeks of feeding, the distal intestine contained between 84-96 Þbaryomyces hanseniiwith few colonies of S. cerevisiae and noW. anomalus. For bacteria, the distal intestine contained between 37-62 % ofLeuconostocaceae,Lactobacillaceae and Photobacteriumand significant differences in taxa abundance and similarity were found between fish fed SC60, WA40 and WA60 compared with the FM diet (Fig. 1). Discussion and conclusion This study is the first to analyse intestinal microbiota of rainbow trout fed yeast diets using next generation sequencing. In addition, few studies have investigated the viability and log reduction of yeast after feed extrusion. The low level of culturable yeast compared with the high level of intact yeast cells found after diet extrusion suggested that high temperature from extrusion inactivated yeasts, but did not disrupt the cells. Inactivated, non-disrupted yeast is not ideal because the yeast cannot cultivate the intestine or release nutrients for metabolic uptake. The lack of S. cerevisiaeandW. anomalusin the distal intestine despite the high level of yeast ingestion, suggests that large amounts of yeast were metabolised. However, higher levels of unculturable yeast cells may have been present in the intestinal content and mucosa. For gut bacteria, most were Lactic Acid Bacteria (Lactobacillales order), which includesCarnobacteriaceae, Leuconstocaceae, Leuconstocaceaeand Streptococcaceae families. In comparison, Ingerslev et al. (2014) found similar levels ofStreptococcus, Leuconostoc,Enterobacteriaceae and Lactobacillusin rainbow trout fed fish and plant-based diets.Significant differences in bacteria abundance for fish fed SC60, WA40 and WA60 diets indicated thatW. anomalushad a higher effect thanS. cerevisiaeand that more than 20% replacement of fish meal with yeast affected gut microbiota in rainbow trout. References Gatesoupe F.J. 2007. Live yeasts in the gut: Natural occurrence, dietary introduction, and their effects on fish health and development. Aquaculture 267: 20-30. Ingerslev H.C., L. von Gersdorff Jørgensen, M. Lenz Strube, N. Larsen, I. Dalsgaard, M. Boye, and L. Madsen. 2014. The development of the gut microbiota in rainbow trout (Oncorhynchus mykiss) is affected by first feeding and diet type. Aquaculture 424-425: 24-34.
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