Researchers at the Norwegian Institute of Food, Fisheries and Aquaculture Research (Nofima) have confirmed that microalgae can exhibit faster growth and increased omega-3 production through selective breeding, making them a more compelling option as a feed ingredient.
The study, led by senior researcher Marie Lillehammer, demonstrates that targeted breeding can notably enhance the omega-3 content in the microalgae Seminavis robusta - a well-studied species with sexual reproduction capabilities.
The experiments, conducted in collaboration with European partners, have yielded promising results, suggesting a potential avenue for utilizing microalgae in European aquaculture feed.
As the foundation of the aquatic food chain, microalgae are emerging as a promising ingredient for farmed fish feed. The efficiency of these ingredients lies in their direct utilization in fish feed, minimizing energy loss compared to alternative sources like krill and small fish.
Marine omega-3 fatty acids, crucial for fish nutrition, are currently primarily sourced from fish oil. Cultivating microalgae with elevated levels of these fatty acids could support the gradual replacement of fish oil in feed formulations, Nofima notes.
While Seminavis robusta is not currently considered a prominent feed resource for omega-3, the study revealed that 18% of the algae's omega-3 production is influenced by genetics. Through selective breeding, this translated to an 8.8% increase in omega-3 content within a single generation.
The research team explored the concept of breeding microalgae, akin to practices employed in farmed fish. By strategically crossing individuals or lineages with superior traits, the researchers were able to produce subsequent generations that exhibited increased performance.
The study showed that, with a heritability of 50%, microalgae could achieve a 25% increase in growth per generation.
However, the researchers note, although this may appear to suggest microalgae's ability to double growth each year, factors such as inbreeding and physiological limitations might impact this over the longer-term.
Lillehammer emphasized the need for further exploration of breeding practices for microalgae, especially if they are to play a significant role in European aquaculture feed.
The research, conducted as part of the EU project NewTechAqua, involved collaboration with the University of Las Palmas in Spain and the University of Ghent in Belgium.
