Optimizing Enchytraeus albidus Production With Agri-Food Waste: A Nutritional Landscape Approach

With aquaculture playing an increasingly important role in global food systems, there is a pressing need for feed innovations that can support industry growth without exacerbating overfishing or environmental degradation. The white worm, Enchytraeus albidus, is a promising substitute live feed candidate capable of growing on a variety of organic waste materials. This study explores the effects of agri-food waste products on the biomass yield, juvenile production, and nutritional composition of E. albidus. Using a nutritional landscape approach, we found that white worm cultures fed baking yeast and oatmeal yielded the highest biomass, while cultures fed fat-reduced oatmeal, spent brewer’s grain, and oatmeal produced the most juveniles. This approach proved valuable for identifying optimal nutrient combinations and visualizing how dietary trade-offs shape growth and reproduction across diverse feed inputs. Diets containing 10%–75% protein, 30%–85% carbohydrate, and 0%–40% lipid, respectively, optimized biomass production, with protein and carbohydrate content serving as critical limiting factors. Juvenile production was primarily influenced by carbohydrate content, with at least 50% carbohydrate needed to achieve more than 85% of the reproduction observed in the control. Feed treatments significantly affected the macronutrient composition of the worms, with high-lipid diets, such as coffee grind and rape seed oil, increasing total fatty acid content. These findings demonstrate the potential of utilizing no- or low-cost feedstock to optimize E. albidus cultivation, providing a cost-effective and sustainable fish feed alternative that could help reduce reliance on marine-derived resources in aquaculture.