Could microorganisms provide a new source of valuable omega-3 fatty acids for aquaculture while reducing dependence on marine resources?
A new article by ONE EARTH partner ANFACO-CYTMA, published in Edizioni Pubblicità Italia, explores this question and presents some of the innovative approaches being investigated within the ONE EARTH project. Entitled “Il futuro dei mangimi passa dai microrganismi: meno pesca, più innovazione” (“The Future of Feed Goes Through Microorganisms: Less Fishing, More Innovation”), the article looks at the growing need for sustainable alternatives to conventional ingredients used in aquaculture feed.
As global demand for aquatic food continues to grow, aquaculture has become an increasingly important source of fish for human consumption. This growth, however, also increases demand for the raw materials needed to produce aquaculture feed. While marine proteins such as fishmeal have increasingly been replaced by alternatives including plant proteins, insect meals, animal by-products and microbial biomass, replacing fish oil remains more challenging. Fish oil is an important source of long-chain omega-3 fatty acids, which are essential for the growth, development and reproduction of farmed fish and help maintain their nutritional value for consumers.
The article highlights microorganisms such as yeasts and bacteria as a promising alternative. They can grow rapidly under controlled conditions and can potentially produce omega-3-rich biomass without depending directly on the availability of natural fish stocks.
Connecting Food Side Streams with Biotechnology
This is where the ONE EARTH approach comes in. The project investigates how organic residues from food production can become resources for entirely new value chains. One pathway begins with residues from the dairy industry, particularly cheese whey. Through controlled microbial fermentation, organic matter in the whey is converted into volatile fatty acids (VFAs), intermediate compounds that can subsequently serve as a carbon source for microorganisms.
Researchers are investigating oleaginous microorganisms, including marine bacteria and yeasts such as Yarrowia lipolytica, for their ability to use these intermediates and accumulate valuable long-chain omega-3 fatty acids. The resulting microbial biomass and extracted fatty acids can then be incorporated into experimental aquaculture feeds.
From the Laboratory to Pilot Scale
The article also highlights the contribution of Università Politecnica delle Marche (UNIVPM), where complementary research teams are working across different stages of this process. The WWEELab research group at the SIMAU Department focuses on optimising the production of volatile fatty acids from organic residues through anaerobic fermentation. Work is progressing from laboratory towards pilot scale, including a system with refrigerated whey storage, a 500-litre fermenter and an ultrafiltration membrane unit.
At the Department of Life and Environmental Sciences (DiSVA), research addresses the other end of the value chain: assessing how the new generation of feeds affects commercially important fish species. Experimental feeds are being investigated for rainbow trout and European seabass. The studies consider factors including growth performance, feed conversion efficiency, intestinal and liver health, immune response and the nutritional value of the edible fish.
Together, these activities will help assess the potential for microbial biomass and microbial fatty acids to replace part of the fish oil currently used in aquaculture diets.
Finding Value in Fish-Processing Residues
The article also presents another part of the ONE EARTH concept: making better use of residues generated by the fish-processing industry. Fish heads, scales, skin and bones contain organic matter and minerals that can potentially become resources for other applications. Among the approaches investigated within ONE EARTH is pyrolysis, a thermochemical process that can convert fish-processing residues into products including biochar. Fish-derived biochar can contain significant amounts of calcium and phosphorus, creating potential for agricultural applications such as soil amendment.
By combining biological and thermochemical processes, ONE EARTH is exploring how residues from different food value chains can become starting materials for new products rather than being treated simply as waste.
Read the full article (in Italian) by ANFACO-CYTMA in Edizioni Pubblicità Italia: https://www.pubblicitaitalia.com/pesce/prodotti/il-pesce/2026/2/24393