Solid-State Fermentation of Distiller’s Dried Grains with Solubles Improves Digestibility for European Seabass (Dicentrarchus labrax) Juveniles

Aquaculture requires new, economical, and eco-friendly protein sources to replace traditional fisheries plant ingredients. Using agriculture by-products as would reduce land-based feed production pressure waste production, promoting a circular economy sustainable aquaculture. Distiller’s dried grains with solubles (DDGS) is the main by-product of bioethanol production. Corn DDGS has high level, but its fiber content limits use ingredient, particularly for carnivorous fish. Solid-state fermentation (SSF) uses lignocellulosic-rich substrates, such DDGS, microbial growth in near absence water, enzyme that degrades lignocellulosic matrix, increasing free reducing sugars, protein, antioxidant levels substrate. In present work, SSF corn Aspergillus carbonarius, A. ibericus, uvarum was tested. Then, digestibility most promising fermented (in terms upgraded nutritional composition) tested by including it reference diet (70% diet; 48% crude protein; 15% lipids) European seabass (Dicentrarchus labrax) juveniles (171 g averaged weight; trial duration 52 days). Among fungi tested, ibericus led generally higher upgrading composition, leading amount (from 42.7 49.7 N/kg DM), phenolic compounds (1.49 4.86 mg/g caffeic acid equivalents), sugars (9.5 31.9 mg/g), (45 U/g 68 cellulase xylanase, respectively), reduction detergent neutral (up 29 43%, respectively). Compared unfermented presented increased lipids, starch, energy digestibility, while phosphorous similar. diet, dietary inclusion or trypsin chymotrypsin activities. The activity digestive enzymes not affected except amylase activity, which lower than diet. conclusion, enhanced value, when included diets juveniles.