Abstract
Growing demand for animal protein and the extensive use of human-edible crops in animal feeds have intensified concerns regarding food–feed competition and the sustainability of global food systems. Aquaculture is expected to play a central role in future food security, yet the production of major farmed species, such as Atlantic salmon, remains highly dependent on imported plant ingredients and finite marine resources. This dependence exposes aquaculture to environmental pressures, market volatility, and supply-chain disruptions. This perspective explores how biotransformation of non-edible agricultural, food and forestry byproducts into microbial proteins (MIs) can reduce competition between the use of biomass for feed and food. Using Paecilomyces variotii (PEKILO®) produced from forestry industry side streams, as an illustrative case, we examine the potential of converting non-edible biomasses into sustainable feed ingredients for salmon. Evidence suggests that MIs can partially replace conventional feed ingredients such as fishmeal and soy protein concentrate, contributing to more circular and resilient food systems. Potential substrates, technological opportunities, and examples of MIs use in aquaculture are reviewed. We propose that structured risk profiles can support risk-based decision-making, facilitate regulatory assessment, and promote safe adoption of novel feed ingredients. Integrating sustainability, food security, and food safety considerations will be essential for scaling biotransformation technologies in future aquaculture production systems.
Introduction
Only 20–25% of annually produced terrestrial agricultural biomass (crops and grasslands) is suitable as human food (Animal Task Force, 2021). Consequently, animals are needed to convert the remaining 75–80% biomass into edible foods. However, less than half of the cereals and vegetable oils were used directly as food in 2023 (Food and Agriculture Organization of the United Nations, FAO, 2025), as around 1/3 of the cereal cropland is used for animal feed production (Animal Task Force, 2021; Muscat et al., 2019). Sustainable food security requires that food-feed competition is resolved (Forte et al., 2023; James et al., 2022; Muscat et al., 2019). One partial solution is the expansion of aquaculture, and today more than half of the world’s seafood supply is produced by aquaculture (FAO, 2026). The expansion of aquaculture has increased pressure on marine resources derived from wild-capture fisheries as well as plant-based feed resources, raising concerns about sustainability and competition between feed and food production (Boyd et al., 2022; Costello et al., 2019). In addition, supply chain disruption, feed cost volatility, and growing environmental concerns are driving the search for alternative feed ingredients (OECD, 2015). Promising solutions include the biotransformation of agro-industrial by-products and food industry by-products into insect and microbial ingredients (MIs), and the use of microalga in aquafeeds (Hua et al., 2019; Cottrell et al., 2020). Such novel feed resources have the potential to partially replace current food-competing feed ingredients (van Riel et al., 2023). To avoid food-feed competition, the substrates for this biotransformation should be based on non-edible biomasses. The risks can be outlined as a risk profile (Joint FAO/WHO Codex Alimentarius Commission, 2007; Ardizzone, 2020; Gupta et al., 2023; Morgan et al., 2022; Wiedmann et al., 2026). We suggest that greater use of risk profiles helps risk-based decision-making on the use of byproducts in aquaculture production systems. We will use the microbial ingredients (MIs), specifically Paecilomyces variotii (PEKILO®), through biotransformation of forestry by-products as an illustrative example of a feed ingredient for Atlantic salmon: first by looking into the sustainability of salmon farming and food-feed competition, then by highlighting possible substrates for biotransformation to MIs and some examples where MIs can substitute other feed ingredients. Some risks might emerge on the demand side, in particular consumer perceptions and public acceptance, but also safety considerations. We will assess regulatory issues, with the caveat that the legislation is rapidly evolving, and suggest some future perspectives.
PEKILO®as example
The PEKILO® production, converting forestry side streams into mycoprotein, was developed by the Finnish forest industry, and was in production between 1975 and 1991 (Ritala et al., 2017; Salo and Pekkarinen, 1981; Ugalde and Castrillo, 2002). It was successfully used as a protein source for pigs and poultry without serious side effects reported. PEKILO® was approved for use as an animal feed ingredient by Finland in 1971, Czechoslovakia in 1978 and Sweden in 1981. Today, PEKILO® is a promising protein source with high nutritional value for salmon (Hooft et al., 2024) and could be commercially available as early as 2026.
PEKILO® entered the EU feed materials catalogue in July 2022, Commission Regulation (EU) 2022/1104, amending Regulation (EU) No 68/2013 (European Commission, 2024). This enables PEKILO®, produced through biotransformation of forestry byproduct (stillage), to partially replace fishmeal and imported plant ingredients. Moreover, a mycoprotein ingredient derived from PEKILO® for human use was submitted for formal review by the US Food and Drug Administration (Enifer, 2026). However, PEKILO® as a meat substitute or used in breadmaking (Koivurinta et al., 1979; Koivurinta et al., 1980) was not a success initially as there were taste issues associated with residual DNA/RNA contents.
Sustainability of salmon farming
Producing 1.6 million tons of salmon in Norway requires around 2 million tons of feed annually (Aas et al., 2022). Of this, more than 90% of the raw materials for salmon feeds are imported (Skavang and Strand, 2024). Salmon feed is pelleted and consists of about 73% plant ingredients, 22% fishmeal and fish oil, and 4% micro-ingredients, such as vitamins, minerals, amino acids and astaxanthin (Aas et al., 2022). Alternative feed sources (microalgae, insects, MI) made up 0.4% of the feed - around 8,000 tons. Feeds are formulated based on ingredient availability, nutritional value, the functional properties of the feed ingredients, costs, and the nutritional requirements of the fish (Glencross, 2020; Thakur et al., 2020).
Marine raw materials used in salmon feed are derived from whole pelagic fish, bycatches, byproducts from industrial fisheries, offcuts and residual raw materials from seafood processing. The materials are processed at reduction plants, where fish oil is extracted and remaining solids are dried and milled into fishmeal. While these ingredients are valuable feedstuffs, it could be more sustainable to valorize them for human consumption (Cadena et al., 2024). The plant-based components originate from soy, sunflowers, rapeseed, corn, peas, and wheat. Soy protein concentrate is the largest single component, accounting for 21% of the total feed volume, and most is imported (81%) from South America (Skavang and Strand, 2024). The wars in Ukraine and the Middle East, with associated shipping delays, demonstrated the fragility of global supply chains and the consequent vulnerability of Norway’s salmon farming. Moreover, imported plant ingredients are the main source of greenhouse gas emissions in salmon farming (Skavang and Strand, 2024).
Food-feed competition
Resolving the competition between food and feed uses of biomass is crucial to a sustainable future (Makkar, 2018; Sandström et al., 2022). Sustainable animal production systems should use feed ingredients not intended for human food. This is not sustainable, as the bioconversion losses in animal food production systems reach up to 90% of edible energy and protein (Makkar and Beever, 2013). Salmon farming has lower greenhouse gas emissions and more efficient feed conversion than meat production from cattle, pigs, poultry, or sheep (Poore and Nemecek, 2018; Aas et al., 2020), and these advantages can be expanded by using locally sourced feed ingredients (Ziegler et al., 2024). This is critical as six out of nine planetary boundaries have already been exceeded (Richardson et al., 2023). Expanding animal production based on cereals and crop production would intensify pressures on the planetary boundaries, while feed ingredients produced from non-edible biomasses not relying on arable land or freshwater would create a more resilient and sustainable supply chain. Other advantages include a more predictable supply and prices of feedstuffs and less exposure to geopolitical challenges. However, EU subsidies incentivize the use of food and forest byproducts for bioethanol production (Schuenemann and Delzeit, 2022) rather than for animal feed or human nutrition, creating competition between food, feed and fuel uses of biomasses.
Byproducts as substrates
Promising feedstocks that could be bio-transformed originate from food industries, e.g., sugar or starch-based products, agricultural byproducts such as straw, and the forestry industries (Devi et al., 2023). A byproduct of sugar production, molasses, is commonly fermented to produce ethanol, which is used in beverages, biofuels, and chemicals. The residual liquid after fermentation, vinasse, can also be a substrate for further biotransformation. Starchy plants such as corn (maize), wheat, rice, cassava, and potatoes are also used in bioethanol production. After ethanol recovery, the remaining residue, stillage, provides a suitable substrate for biotransformation and can be combined with the solid fraction (distiller’s dried grains, DDG) (Bušić et al., 2018). In addition, biorefineries processing lignocelluloses, such as wood, straw, and corn cobs, offer suitable byproducts for PEKILO® production, such as pre-hydrolysis liquor (PHL) from dissolving pulp production (Bušić et al., 2018). Currently accessible forestry byproducts from traditional sulphite pulping are stillage and hydrolyzed residual wood biomass (e.g., sawdust). Black liquor, a side stream of the Kraft pulping process, has the largest volumes; however, its use in fermentation would require pre-treatments.
Biotransformation of byproducts
The terms byproducts and side streams are used interchangeably, confusing readers. We suggest the following understanding: byproducts are secondary products that drive neither the profits nor the production decisions of a business, while side streams include all byproducts, materials and energy generated by a primary product. Byproducts could be disposed of as waste or upcycled to valuable products (Poltronieri and D'Urso, 2016), and upcycling could create additional business opportunities (Dou et al., 2024; Garcia-Valencia et al., 2026). These byproducts can be transformed into higher-value products such as food and feed ingredients, materials, fibers or biofuels rather than being discarded or incinerated (Glencross et al., 2025). Byproducts, such as molasses, sugar syrup, alcohol, distillery waste, cereals, fruit juice, whey, lactic acid, plant fibers, fermentation byproducts, and spent sulphite liquor, can be converted by microbes into valuable feed ingredients such as microbial ingredients (MI) (Ritala et al., 2017). A critical priority is finding alternative feed sources for aquaculture that do not compete with human food use. There are several studies suggesting this approach could help find sustainable salmon feed ingredients replacing soy and marine biomass. Øverland et al. (2013) investigated the effect of replacing about 40% of fishmeal protein with different yeasts in Atlantic salmon diets. The growth performance depended strongly on yeast type. Fish fed Candida utilis or Kluyveromyces marxianus showed similar growth, feed conversion, and nutrient utilization as fishmeal-fed controls, indicating these yeasts are promising alternative protein sources to fishmeal. Moreover, Hatlen et al. (2012) demonstrated that Yarrowia lipolytica biomass can be used as a feed ingredient in Atlantic salmon diets, but the effect was strongly dependent on inclusion levels. Moderate inclusion supported acceptable growth and feed utilization, while higher levels led to reduced performance, indicating nutritional or digestibility limitations. Y. lipolytica contributed to a significant increase in EPA (Eicosapentaenoic acid) deposition in fish tissues, highlighting its value as a functional lipid ingredient. Grain distillers dried yeast (GDDY) can replace fishmeal in diets for juvenile rainbow trout, with moderate inclusion levels supporting comparable growth performance and feed efficiency (Hauptman et al., 2014). However, higher replacement levels tended to reduce growth and feed utilization, indicating limitations related to nutrient balance or digestibility. Vidakovic et al. (2020) found that yeast can replace fishmeal in rainbow trout diets up to 40% without negative effects on growth, nutrient digestibility, or overall fish health. At higher inclusion levels (60%), performance declined: specific growth rate decreased, feed intake was reduced, and protein and amino acid digestibility were lower compared to the fishmeal control. High yeast inclusion appears to be associated with signs of intestinal stress, including mucosal changes and increased mucus production, indicating reduced gut health. Overall, the studies showed that yeast can replace a proportion of fishmeal, but only certain yeast species, maintained growth performance, highlighting the importance of selecting appropriate yeast sources. The importance of species and downstream processing was underlined by Øverland et al. (2013), who found that fish fed Saccharomyces cerevisiae had reduced growth and feed efficiency, suggesting a lower nutritional value. Evidence for filamentous fungi as protein sources in salmonid feeds remains limited. The strongest published growth-performance data are currently available for Paecilomyces variotii (PEKILO®) in Atlantic salmon and rainbow trout. In Atlantic salmon, a single freshwater feeding trial reported that PEKILO® could replace up to 20% of the dietary crude protein without compromising growth performance (Hooft et al., 2024), while in rainbow trout growth was maintained at dietary inclusion levels up to 20% of the diet (Gaudhaman et al., 2026). These findings are currently supported by only two freshwater feeding trials, both conducted by research teams that partially overlap with the authors of the present review. Consequently, additional independent studies also including marine environments, are required before broader conclusions can be drawn regarding the use of P. variotii in salmonid feeds.
Consumer perception and reputational risks
Food business operators (FBO) in aquaculture must carefully manage risks related to consumer demand (food scares) and supply chains. Food scares, while not highly likely, pose tangible risks due to large economic consequences. The European Union (EU) is the key market for Norwegian salmon, and EU consumer perception influences demand. European consumers tend to favor wild fish over farmed, citing concerns about appearance, smell, taste, and high prices as reasons for reduced fish consumption (Menozzi et al., 2020). While accurate, positive information on sustainability can improve consumer attitudes (Menozzi et al., 2020), negative news tends to have a stronger impact. Maintaining consumer trust that farmed salmon is healthy is important considering salmon’s price inelasticity: a small drop in demand causes a large drop in price for the market to clear (price elasticity estimates: frozen salmon −0.37, fresh salmon −0.87; Xie et al., 2009). Consequently, food safety scares can have major consequences for demand, prices, and aquaculture profits. Events with a low probability that damage trust, such as health or environmental concerns, may cause significant economic losses.
Public acceptance of aquaculture
It appears the aquaculture industry has conditional acceptance in Norway (Schei Olsen et al., 2023), as most Norwegian consumers (75%) view the aquaculture industry positively or neutrally, but only 60% believe salmon is produced sustainably. While there is broad acceptance of salmon farming (85% positive or neutral), this support drops to 60% when it comes to industry expansion and Schei Olsen et al. (2023) found that while most of the Norwegian public thought the aquaculture industry was important, the distribution of benefits was unfair. Partly justified by the inequitable distribution of the benefits, the Norwegian government imposed a resource rent tax on salmon production (Misund et al., 2024).
Safety concerns
When introducing novel biotransformation-derived ingredients, monitoring for the presence of hazards is essential (EFSA Scientific Committee, 2015). Safety depends on controlling the substrates, as processing may not eliminate contaminants like heavy metals (Amara and El-Baky, 2023). We suggest that using risk profiles (Joint FAO/WHO Codex Alimentarius Commission, 2007) can be helpful for risk management, and in Table 1, some elements of a risk profile for PEKILO® mycoproteins are outlined. The concerns when introducing microbial ingredients in salmon feed include: (a) toxins produced by microorganisms in particular those that are heat stable; (b) allergens (Amara and El-Baky, 2023); (c) chemical and biological hazards in the substrate that is not inactivated during the processes from substrate to feed such as heavy metals and prions, respectively; and (d) nucleic acid (DNA/RNA) content because ingestion of purine compounds can cause high uric acid concentrations in plasma (Ritala et al., 2017). However regarding the last point, salmon has an efficient uricolytic pathway involving enzymes that metabolize purines (Andersen et al., 2006). P. variotii is not listed in EFSA’s Qualified Presumption of Safety (QPS) list (EFSA BIOHAZ Panel, 2024; EFSA BIOHAZ Panel, 2026), due to limited data on toxicological effects. Like many thermophilic filamentous fungi, Paecilomyces variotii pose risks to immune-compromised individuals and animals (Moreira et al., 2018; Borba and Brito, 2015; Ham et al., 2016). The concern is that contaminated food could serve as a fomite, facilitating aerosol transmission. Kofoed et al. (2024) reported that P. variotii was associated with occupational health issues at Danish biowaste plants, illustrating the concern for occupational health risks in handling or processing feedstuffs with P. variotii. Additionally, P. variotii is a spoilage organism in food and beverages (Moreira et al., 2018). Nevertheless, fungal single-cell protein production based on a specific P. variotii strain was already scaled up to commercial production in Finland in the 1970s and used in the feed industry with no adverse effects reported (Romantschuk and Lehtomäki, 1978). One concern is that P variotii spores are heat resistant and survive up to 15 min in 100⁰ C (Piecková and Samson, 2000). On the other hand, safety steps for fish feedstuffs with PEKILO® mycoproteins (Figure 1) include heat treatments during substrate sterilization (100–130 °C for 5–30 min) and extrusion in pellet production (100–150 °C, at ~90 bar) (Hooft et al., 2024). These processes should be effective at killing most pathogens and inactivating most toxins. However, these processes cannot guarantee elimination of spore-forming microbes including P variotii and heat-stable toxins. Consequently, control of substrates used in biotransformation is crucial.
Table 1
| Hazards | Likelihood | Consequences | Affected stakeholders | Mitigation options | Knowledge gaps |
|---|---|---|---|---|---|
| Biological hazards | |||||
| Bacteria | Low | Medium | Feed producers, fish farmers | Heat treatments | House flora – processing plants, risk introduction after heat treatment |
| Spore forming bacteria | Low-Medium | Medium | Feed producers, fish farmers | Heat treatments, control of substrates | Survival of heat treatment, risk introduction after heat treatment |
| Parasites | Low | Medium | Feed producers, fish farmers | Heat treatments | Risk introduction after heat treatment |
| Viruses | Low | Medium | Feed producers, fish farmers | Heat treatments | Risk introduction after heat treatment |
| Chemical hazards | |||||
| Persistent organic pollutants POPs – polychlorinated biphenyls (PCB) dioxins, chlorinated pesticides, brominated flame retardants, | Low - Medium (but dependent on the substrate origin and type) | High | Feed producers, fish farmers, fish processors, retail and wholesale, and consumers | Control and surveillance of substrates. Risk-based monitoring | Which substrates are contaminated, variation of contamination and causes thereof |
| Heavy metals (As, Pb, Cd, Hg) | Low – Medium (but dependent on the substrate origin and type) | Medium – High | Feed producers, fish farmers, fish processors, retail and wholesale, and consumers | Control and surveillance of substrates. Risk-based monitoring | Which substrates are contaminated, variation of contamination and causes thereof |
| Antimicrobial substances | Low | Low- Medium | Feed producers, fish farmers, fish processors, retail and wholesale, and consumers | Control of substrate, | Presence in substrates, |
| Mycotoxins | Low | Medium | Feed producers, fish farmers, fish processors, retail and wholesale, and consumers | Control of substrate and processing, storage, and distribution | Presence in substrates, possibilities for growth and toxin production during processing and storage |
| Agricultural residues, pesticides, herbicides | Low (but dependent on the substrate origin and type) | Medium | Feed producers, fish farmers, fish processors, retail and wholesale, and consumers | Control of substrate | Presence in substrates |
| Process contaminants and additives (processing byproducts, e.g., acrylamides, feed additives) | Low (but dependent on the type of process) | Low-Medium | Feed producers, fish farmers, fish processors, retail and wholesale, and consumers | Control of process | Could the process, e.g., heat treatment cause acrylamides? |
Risk profile for use of PEKILO® (Paecilomyces variotii) mycoprotein in diets for Atlantic salmon using forestry byproducts as an example.
The likelihood and consequences are based on expert (the authors) judgments. This table is the starting point for an iterative risk analysis where resources prioritized for getting more refined assessments of likelihood and consequences, for those hazards that appear to be critical for risk management.
Figure 1
Discussion
The importance of food safety to public health is reflected in its inclusion in the United Nations Sustainable Development Goals - SDG 2 (Zero Hunger), SDG 3 (Good Health and Well-being), and SDG 12 (Responsible Consumption and Production), and the World Health Organization’s food safety strategy (World Health Organization, 2022; Wiedmann et al., 2026). Food safety is tied to broader food security, public health and sustainability goals for food value chains (Monteiro et al., 2024; Vågsholm et al., 2020). The World Health Organization (2022) noted that practical risk management options for foodborne risks from changes in food value chains are needed for future food security. We suggest that greater use of risk profiles (Table 1) would improve the interface between industry, risk assessors and regulators and facilitate approvals of and the use of non-edible byproducts in aquaculture production systems (Joint FAO/WHO Codex Alimentarius Commission, 2007).
While food business operators (FBOs) are responsible for ensuring the safety of all food and feed products under the European Union’s General Food Law (Regulation (EU) 178/2002), the approval process for novel foods and feeds could be simplified without compromising safety to facilitate sustainability. Unclear regulations, weak economic incentives and limited awareness (Mubarik et al., 2024) are hurdles for implementing circular and sustainable food production systems. The interactions and communication between risk–benefit assessors and regulators are of utmost importance for a working regulatory process (Monteiro et al., 2024). The Novel Food Regulation (2015/2283) and the GM Food Regulation (1823/2003) appear in their current implementations, to limit the transformative potential of novel foods and animal feed ingredients in Europe and obstruct development of sustainable food value chains. In future legislation, food security, safety, resilience of food value chains and sustainability should be carefully aligned (Lähteenmäki-Uutela et al., 2021).
Sandström et al. (2022) found that up to 68, 49 and 38% of poultry feeds, aquaculture and pig feeds, respectively, consist of ingredients edible to humans. There is urgency to change the aquaculture value chain and reduce the food-feed competition (Chary et al., 2024). Edible biomasses should end up on a plate, while non-edible biomasses should end up as animal feeds. A one nutrition system (Pinotti et al., 2025) where animals, including fish, can convert the non-edible biomasses into edible food and manure as a source of nutrients for plants and soils, is one step toward sustainable food production systems without compromising food safety.
Statements
Data availability statement
The original contributions presented in the study are included in the article, further inquiries can be directed to the corresponding author/s.
Author contributions
IV: Writing – original draft, Writing – review & editing. LM: Writing – original draft, Writing – review & editing. JH: Writing – original draft, Writing – review & editing. AG: Writing – original draft, Writing – review & editing. KB: Writing – original draft, Writing – review & editing. MØ: Writing – original draft, Writing – review & editing.
Funding
The author(s) declared that financial support was received for this work and/or its publication. This study was supported by the NORDICFEED project ‘Biokonvertering av. bioresurser’ (Project No. 24931000/3277068), funded by FORMAS and NORDFORSK, and the Research Council of Norway (RCN); and the ForestFeed project ‘En nordisk blågrön värdekedja från skog till fiskfilé’ (Project No. 2023-00132/344116) funded by VINNOVA, RCN, and Bioeconomy in the North.
Conflict of interest
The author(s) declared that this work was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
The author(s) KB declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision.
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References
1
AasT. S.ÅsgårdT.YtrestøylT. (2020). Utilization of feed resources in the production of Atlantic salmon (Salmo salar) in Norway: an update for 2020. Aquaculture Reports.26:101316. doi: 10.1016/j.aqrep.2022.101316,
2
AasT. S.YtrestøylT.ÅsgårdT. (2022). Utnyttelse av fôrressurser i norsk oppdrett av laks og regnbueørret i 2020. Available online at: https://havbruk2022.no/foredrag/utnyttelse-av-forressurser-i-norsk-oppdrett-av-laks-og-orret-i-2020 (Accessed July 11, 2024)
3
AmaraA. A.El-BakyN. A. (2023). Fungi as a source of edible proteins and animal feed. J. Fungi9:73. doi: 10.3390/jof9010073,
4
AndersenØ.AasT. S.SkugorS.TakleH.van NesS.Grisdale-HellandB.et al. (2006). Purine-induced expression of urate oxidase and enzyme activity in Atlantic salmon (Salmo salar). Cloning of urate oxidase liver cDNA from three teleost species and the African lungfish Protopterus annectens. FEBS J.273, 2839–2850. doi: 10.1111/j.1742-4658.2006.05288.x,
5
Animal Task Force. (2021). Going beyond feed versus food: crops and animals together to address food and nutrition security. Report of the One-day Symposium of the Animal Task Force and the EAAP Livestock Farming Systems Commission, Davos, Switzerland. Available online at: http://animaltaskforce.eu/wp-content/uploads/2024/10/EAAP2021_ATF-LFS_one-day_symposium_report.pdf (Accessed March 18, 2026)
6
ArdizzoneM. (2020). Emerging Risks Associated With Feed and Products of Feed Production Technologies of Increasing Relevance (Novel Feeds). EFSA Briefing Note ID0423. Available online at: https://www.efsa.europa.eu/sites/default/files/event/2020/6.2-novel-feed.pdf (Accessed July 9, 2024)
7
BorbaC. M.BritoM. M. S. (2015). “Paecilomyces: mycotoxin production and human infection,” in Molecular Biology of Food and Water Borne Mycotoxigenic and Mycotic Fungi, eds. PatersonR. R. M.LimaN. (Boca Raton, FL: CRC Press), 401–421.
8
BoydC. E.McNevinA. A.DavisR. P. (2022). The contribution of fisheries and aquaculture to the global protein supply. Food Secur.14, 805–827. doi: 10.1007/s12571-021-01246-9,
9
BušićA.MarđetkoN.KundasS.MorzakG.BelskayaH.Ivančić ŠantekM.et al. (2018). Bioethanol production from renewable raw materials and its separation and purification: a review. Food Technol. Biotechnol.56, 289–311. doi: 10.17113/ftb.56.03.18.5546,
10
CadenaE.KocakO.DewulfJ.IñarraB.BaldC.GutierrezM.et al. (2024). Valorisation of seafood side streams through the Design of new Holistic Value Chains: WaSeaBi project. Sustainability16:1846. doi: 10.3390/su16051846
11
CharyK.HenrikssonP. J. G.TroellM. (2024). Competition for human edible feed resources in aquaculture - looking at tilapia farming. Food Secur.17, 57–72. doi: 10.1007/s12571-024-01513-5,
12
CostelloC.CaoL.GelcichS. (2019). The Future of Food from the Sea. Washington, DC: World Resources Institute. Available online at: http://www.oceanpanel.org/future-food-sea (Accessed June 4, 2026)
13
CottrellR. S.BlanchardJ. L.HalpernB. S.MetianM.FroehlichH. E. (2020). Global adoption of novel aquaculture feeds could substantially reduce forage fish demand by 2030. Nat. Food1, 301–308. doi: 10.1038/s43016-020-0078-x
14
DeviA.BajarS.SihagP.SheikhZ. U. D.SinghA.KaurJ.et al. (2023). A panoramic view of the technological landscape for bioethanol production from various generations of feedstocks. Bioengineered14, 81–112. doi: 10.1080/21655979.2022.2095702,
15
DouZ.DierenfeldE. S.WangX.ChenX.ShursonG. C. (2024). A critical analysis of challenges and opportunities for upcycling food waste to animal feed to reduce climate and resource burdens. Resour. Conserv. Recycl.203:107418. doi: 10.1016/j.resconrec.2024.107418
16
EFSA BIOHAZ Panel (2024). Update of the list of qualified presumption of safety (QPS) recommended microbiological agents intentionally added to food or feed as notified to EFSA 19: suitability of taxonomic units notified to EFSA until September 2023. EFSA J.22. doi: 10.2903/j.efsa.2024.8517,
17
EFSA BIOHAZ Panel (2026). Update of the list of QPS-recommended biological agents intentionally added to food or feeds as notified to EFSA. EFSA J.24. doi: 10.2903/j.efsa.2026.9823,
18
EFSA Scientific Committee (2015). Scientific opinion on a risk profile related to production and consumption of insects as food and feed. EFSA J.13:4257. doi: 10.2903/j.efsa.2015.4257
19
Enifer. (2026). Enifer Moves PEKILO® into FDA Review. Available online at: https://enifer.com/enifer-moves-PEKILO®-into-fda-review (Accessed April 14, 2026)
20
European Commission. (2024). EU Novel Food Status Catalogue. Available online at: https://ec.europa.eu/food/food-feed-portal/screen/novel-food-catalogue/search (Accessed April 14, 2024)
21
Food and Agriculture Organization of the United Nations (FAO) (2026). In Brief to the State of World Fisheries and Aquaculture 2026: Blue Transformation: Turning Vision into Impact. Rome: FAO.
22
Food and Agriculture Organization of the United Nations, FAO (2025). Food Balance Sheets 2010–2023. FAOSTAT Analytical Brief Series No. 112. Rome: FAO.
23
ForteC.Lo FiegoD. P.Trabalza MarinucciM.PravettoniD.NatalelloA. (2023). Editorial: efforts to reduce feed-food competition. Front. Vet. Sci.10:1335007. doi: 10.3389/fvets.2023.1335007,
24
Garcia-ValenciaM.SvartebekkK. M.AltintzoglouT.GaarderM. Ø. (2026). A perspective of upcycled food by Norwegian consumers: the meaning without the word. J. Int. Food Agribus. Mark.38, 1–24. doi: 10.1080/08974438.2025.2475480
25
GaudhamanA.VidakovicA.WarwasN.DoyleD.Morales-LangeB.ØverlandM.et al. (2026). Paecilomyces Variotii Mycoprotein in Diets for Juvenile Rainbow Trout: Effects on Growth Performance, Intestinal Health and Technical Feed Quality. Aquac Nutr2026:4320030. doi: 10.1155/anu/4320030,
26
GlencrossB. (2020). A feed is still only as good as its ingredients: an update on the nutritional research strategies for the optimal evaluation of ingredients for aquaculture feeds. Aquac. Nutr.26, 1871–1883. doi: 10.1111/anu.13138
27
GlencrossB.BureauD.ØverlandM.SimonC.ValenteL. M. P.GraceyE.et al. (2025). Toward applying a circularity framework against the use of aquaculture feed ingredients. Rev. Fish. Sci. Aquac.34, 343–356. doi: 10.1080/23308249.2025.2552166,
28
GuptaR.ShankarR.LaiK. H.KumarA. (2023). Risk profiling of food security impediments using decision maker's behavioural preference towards operational risk management. Ann. Oper. Res.4, 1–36. doi: 10.1007/s10479-022-05148-7,
29
HamH.KimS.KimM.LeeS.HongS. K.RyuJ.et al. (2016). Mycobiota of ground red pepper and their aflatoxigenic potential. J. Microbiol.54, 832–837. doi: 10.1007/s12275-016-6480-2,
30
HatlenB.BergeG. M.OdomJ. M.MundheimH.RuyterB. (2012). Growth performance, feed utilisation and fatty acid deposition in Atlantic salmon, Salmo salar L., fed graded levels of high-lipid/high-EPA Yarrowia lipolytica biomass. Aquaculture364-365, 39–47. doi: 10.1016/j.aquaculture.2012.07.005,
31
HauptmanB. S.BarrowsF. T.BlockS. S.GibsonG. T.PatersonJ. A.RawlesS. D.et al. (2014). Evaluation of grain distillers dried yeast as a fish meal substitute in practical-type diets of juvenile rainbow trout, Oncorhynchus mykiss. Aquaculture432, 7–14. doi: 10.1016/j.aquaculture.2014.03.026
32
HooftJ. M.MonteroR.Morales-LangeB.BlihovdeV. F.PurushothamanK.PressC. N.et al. (2024). Paecilomyces variotii (PEKILO®) in novel feeds for Atlantic salmon: effects on pellet quality, growth performance, gut health, and nutrient digestibility and utilization. Aquaculture589:740905. doi: 10.1016/j.aquaculture.2024.740905
33
HuaK.CobcroftJ. M.ColeA.CondonK.JerryD. R.MangottA.et al. (2019). The future of aquatic protein: implications for protein sources in aquaculture diets. One Earth1, 316–329. doi: 10.1016/j.oneear.2019.10.018
34
JamesK.MillingtonA.RandallN. (2022). Food and feed safety vulnerabilities in the circular economy. EFSA J.19:7226E. doi: 10.2903/sp.efsa.2022.EN-7226
35
Joint FAO/WHO Codex Alimentarius Commission. (2007). Principles and Guidelines for the Conduct of Microbiological Risk Management (CXG 63-2007). Rome: FAO/WHO. Available online at: https://www.fao.org/input/download/standards/10741/CXG_063e.pdf (Accessed June 9, 2026)
36
KofoedV. C.CampionC.RasmussenP. U.MøllerS. A.EskildsenM.NielsenJ. L.et al. (2024). Exposure to resistant fungi across working environments and time. Sci. Total Environ.923:171189. doi: 10.1016/j.scitotenv.2024.171189,
37
KoivurintaJ.KurkelaR.KoivistoinenP. (1979). Uses of PEKILO®, a microfungus biomass from Paecilomyces variotii in sausage and meat balls. Int. J. Food Sci. Technol.14, 561–570. doi: 10.1111/j.1365-2621.1979.tb00902.x
38
KoivurintaJ.KurkelaR.KoivistoinenP.HolasováM.BlattnáJ. (1980). Bread baking properties of PEKILO®, a microfungus biomass from Paecilomyces variotii. Nahrung24, 597–606. doi: 10.1002/food.19800240702
39
Lähteenmäki-UutelaA.RahikainenM.LonkilaA.YangB. (2021). Alternative proteins and EU food law. Food Control130:108336. doi: 10.1016/j.foodcont.2021.108336
40
MakkarH. P. S. (2018). Review: feed demand landscape and implications of food-not feed strategy for food security and climate change. Animal12, 1744–1754. doi: 10.1017/S175173111700324X,
41
MakkarH. P. S.BeeverD. (2013). Optimization of feed use efficiency in ruminant production systems. In: Proceedings of the FAO Symposium, 27 November 2012, Bangkok, Thailand. FAO Animal Production and Health Proceedings No. 16. Rome: FAO and Asian-Australasian Association of Animal Production Societies.
42
MenozziD.NguyenT. T.SogariG.TaskovD.LucasS.Castro-RialJ. L. S.et al. (2020). Consumers' preferences and willingness to pay for fish products with health and environmental labels: evidence from five European countries. Nutrients12:2650. doi: 10.3390/nu12092650,
43
MensahD. D. (2025). NMBU PhD Thesis 2025:24 [Doctoral Dissertation]. Norwegian University of Life Sciences (NMBU). Available online at: https://www.nb.no/items/URN:NBN:no-nb_digibok_2025032448061 (Accessed July 17, 2026).
44
MisundB.MolnárP.NguyenQ. M.TotlandE. (2024). Impact of rent taxation on Norwegian salmon farming companies. Aquac. Econ. Manag.29, 1–20. doi: 10.1080/13657305.2024.2342268,
45
MonteiroC. D. M.MembréJ. M.PoulsenM.ThomsenS. T.PiresS. M. (2024). Risk–benefit assessment of foods and its role to inform policy decisions: outcome of an international workshop. Front. Nutr.11:1458531. doi: 10.3389/fnut.2024.1458531,
46
MoreiraD. C.OliveiraM. M. E.BorbaC. M. (2018). Human pathogenic Paecilomyces from food. Microorganisms6:64. doi: 10.3390/microorganisms6030064,
47
MorganK. M.CrawfordA.KowalcykB. B. (2022). Risk-based decision making definition: a scoping review of food, agricultural, environmental, and medical literature. Risk Anal.42, 2107–2121. doi: 10.1111/risa.13845,
48
MubarikM. S.KontoleonA.ShahbazM. (2024). Beyond the hurdles: exploring policy obstacles in the path to circular economy adoption. J. Environ. Manag.370:122667. doi: 10.1016/j.jenvman.2024.122667,
49
MuscatA.de OldeE. M.de BoerI. J. M.Ripoll-BoschR. (2019). The battle for biomass: a systematic review of food-feed-fuel competition. Glob. Food Sec.25:100330. doi: 10.1016/j.gfs.2019.100330,
50
OECD (2015). Green Growth in Fisheries and Aquaculture. OECD Green Growth Studies. Paris: OECD Publishing.
51
ØverlandM.KarlssonA.MydlandL. T.RomarheimO. H.SkredeA. (2013). Evaluation of Candida utilis, Kluyveromyces marxianus and Saccharomyces cerevisiae yeasts as protein sources in diets for Atlantic salmon (Salmo salar). Aquaculture402-403, 1–7. doi: 10.1016/j.aquaculture.2013.03.016,
52
PieckováE.SamsonR. A. (2000). Heat resistance of Paecilomyces variotii in sauce and juice. J. Ind. Microbiol. Biotechnol.24, 227–230. doi: 10.1038/sj.jim.2900794,
53
PinottiL.CheliF.GovoniC.RulliM. C.PremarajanP.CattaneoD. M. I. R. (2025). The "one nutrition" approach: connecting crop production, animal nutrition and human nutrition. Ital. J. Anim. Sci.24, 978–987. doi: 10.1080/1828051X.2025.2488956
54
PoltronieriP.D'UrsoO. F. (2016). Biotransformation of Agricultural Waste and By-Products: The Food, Feed, Fibre, Fuel (4F) Economy. London: Elsevier.
55
PooreJ.NemecekT. (2018). Reducing food's environmental impacts through producers and consumers. Science360, 987–992. doi: 10.1126/science.aaq0216,
56
RichardsonK.SteffenW.LuchtW.BendtsenJ.CornellS. E.DongesJ. E.et al. (2023). Earth beyond six of nine planetary boundaries. Sci. Adv.9:eadh2458. doi: 10.1126/sciadv.adh2458,
57
RitalaA.HäkkinenS. T.ToivariM.WiebeM. G. (2017). Single cell protein: state-of-the-art, industrial landscape and patents 2001–2016. Front. Microbiol.8:2009. doi: 10.3389/fmicb.2017.02009,
58
RomantschukH.LehtomäkiM. (1978). Operational experiences of first full-scale PEKILO® SCP mill application. Process Biochem.13, 16–29.
59
SaloM. L.PekkarinenE. (1981). Nutritive value for growing pigs of PEKILO® protein and torula yeast grown in spent sulphite liquor. Agric. Food Sci.53, 52–56. doi: 10.23986/afsci.72055
60
SandströmV.ChrysafiA.LamminenM.TroellM.JalavaM.PiipponenJ.et al. (2022). Food system byproduct upcycled in livestock and aquaculture feeds can increase global food supply. Nat. Food3, 729–740. doi: 10.1038/s43016-022-00589-6,
61
Schei OlsenM.Steiro AmundsenV.OsmundsenT. C. (2023). Exploring public perceptions and expectations of the salmon aquaculture industry in Norway: a social license to operate?Aquaculture574:739632. doi: 10.1016/j.aquaculture.2023.739632,
62
SchuenemannF.DelzeitR. (2022). Potentials, subsidies and trade-offs of cellulosic ethanol in the European Union. Ecol. Econ.195:107384. doi: 10.1016/j.ecolecon.2022.107384
63
SkavangP. K.StrandA. V. (2024). Conceptualization of the Norwegian feed system of farmed Atlantic salmon. Front. Mar. Sci.11:1378970. doi: 10.3389/fmars.2024.1378970
64
ThakurM.JohansenU.JafarzadehS.CechuraL.RumankovaL.KroupovaZ. Z.et al. (2020). Report on Information and Material Flow Analysis for the Selected Case Studies. VALUMICS Project Deliverable D4.3. Trondheim: SINTEF Ocean.
65
UgaldeU. O.CastrilloJ. I. (2002). Single cell proteins from fungi and yeasts. Appl. Mycol. Biotechnol.2, 123–149. doi: 10.1016/S1874-5334(02)80008-9
66
VågsholmI.ArzoomandN. A.BoqvistS. (2020). Food security, safety, and sustainability: getting the trade-offs right. Front. Sustain. Food Syst.4:16. doi: 10.3389/fsufs.2020.00016
67
Van RielA. J.NederlofM. A. J.CharyK.WiegertjesG.de BoerI. J. M. (2023). Feed-food competition in global aquaculture: current trends and prospects. Rev. Aquac.15, 1142–1158. doi: 10.1111/raq.12804
68
VidakovicA.HuybenD.SundhH.NymanA.VielmaJ.PassothV.et al. (2020). Growth performance, nutrient digestibility and intestinal morphology of rainbow trout (Oncorhynchus mykiss) fed graded levels of the yeasts Saccharomyces cerevisiae and Wickerhamomyces anomalus. Aquac. Nutr.26, 275–286. doi: 10.1111/anu.12988
69
WiedmannM.SunilS.Moreno-SwittA. I.VongkamjanK.JohlerS. (2026). Balancing food safety and sustainability: trade-off risk assessments and predictive modeling. Front. Sci.4:1720772. doi: 10.3389/fsci.2026.1720772
70
World Health Organization. (2022). WHO Global Strategy for Food Safety 2022–2030: Towards Stronger Food Safety Systems and Global Cooperation. Geneva: World Health Organization. Available online at: https://www.who.int/publications/i/item/9789240057685 (Accessed April 14, 2026)
71
XieJ.KinnucanH. W.MyrlandO. (2009). Demand elasticities for farmed salmon in world trade. Eur. Rev. Agric. Econ.36, 425–445. doi: 10.1093/erae/jbp028
72
ZieglerF.NistadA. A.LangelandM.WockenY.HognesE. S.MehtaS. (2024). Greenhouse gas emission reduction opportunities for the Norwegian salmon farming sector: can they outweigh growth?Aquaculture581:740431. doi: 10.1016/j.aquaculture.2023.740431
Summary
Keywords
biotransformation, byproduct, feed, mycoprotein, Paecilomyces variotii, resilience, risk profile, salmon
Citation
Vågsholm I, Mydland LT, Hooft JM, Gaudhaman A, Baruah K and Øverland M (2026) Safety concerns when reducing food-feed competition through biotransformation of non-edible byproducts to microbial proteins—the example of Paecilomyces variotii in diets for Atlantic salmon. Front. Sustain. Food Syst. 10:1855614. doi: 10.3389/fsufs.2026.1855614
Received
14 April 2026
Revised
10 August 2026
Accepted
11 August 2026
Published
08 September 2026
Volume
10 - 2026
Edited by
Juan Manuel Vera Delgado, Technical University of Manabi, Ecuador
Reviewed by
Rocco Pavesi, University of Milan, Italy
Yash Khalasi, Central Institute of Fisheries Education (ICAR), India
Updates
Copyright
© 2026 Vågsholm, Mydland, Hooft, Gaudhaman, Baruah and Øverland.
This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
*Correspondence: Ivar Vågsholm, Ivar.Vagsholm@slu.se; Margareth Øverland, Margareth.Overland@nmbu.no
ORCID: Ivar Vågsholm, orcid.org/0000-0002-1661-0677; Liv Torunn Mydland, orcid.org/0000-0002-9361-3687; Jamie M. Hooft, orcid.org/0000-0003-4748-8333; Ashwath Gaudhaman, orcid.org/0000-0002-1563-7480; Kartik Baruah, orcid.org/0000-0002-2060-4982; Margareth Øverland, orcid.org/0000-0003-1142-6624
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