The European Union (EU) is dependent on imports of soya beans to meet its domestic needs. In this respect, the development of alternative endemic feed ingredients is key to decrease its dependence. Legumes such as Lupinus albus, with their high protein content and balanced amino acid profile, are promising candidates. However, the presence of anti-nutritional factors (ANF) that inhibit enzymatic activity and the absorption of other nutrients restricts their use in feeds. Solid-state fermentation is a novel technology in the field of animal nutrition for utilising plant ingredients. Microorganisms, such as Saccharomyces cerevisiae, have the ability to produce enzymes and bioactive metabolites and reduce ANF’s during fermentation (Ihtifazhuddin et al., 2016, Dileep et al., 2021). The aim of the present study was the replacement of soybean meal by Lupin meal fermented with Saccharomyces cerevisiae, in European sea bass nutrition.
Lupin seeds were fermented by inoculation with Saccharomyces cerevisiae at a concentration of 1^10E6/g of substrate. Four diets were formulated, one control containing only soybean meal and three diets replacing soybean meal by fermented lupin meal in three different levels 67, 83 and 100%. Juvenile sea bass (18.9 g initial weight) were fed the experimental feeds ad libitum three times per day for a period of 71 days.
In the current study inclusion of fermented lupin meal, revealed positive results. Specifically, the population fed diets with fermented lupin showed higher final weight (62.5-63.8g) in contrast to the population fed control diet. Even though FCR did not show significant differences, a trend (P=0.09) for lower FCR was observed for fish treated with FRL2 compared to those treated with control diet. Significantly higher digestibility of protein observed for the groups fed diets FRL2 and FRL3 compared to control group. These results showed that fermented lupin is a promising alternative to soya for Mediterranean aquaculture.