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

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.