Application of fermented brewer's spent grain extract in plant-based diets for European seabass juveniles

Available online 10 February 2022
This work aimed to evaluate the potential of a carbohydrases-rich extract produced by SSF of BSG to enhance the nutritional value of plant-based diets for European seabass (Dicentrarchus labrax) juveniles. BSG was fermented by A. ibericus (MUM 03.49) to obtain an aqueous enzymatic extract (1178 and 8317Ug1 cellulase and xylanase activity, respectively). A control (50% protein; 18% lipids) diet was formulated with 55% DM of plant-feedstuffs (PF), and four other diets were formulated similarly to the control but including 0.4% and 0.8% DM of lyophilized extract (BSG-extract), corresponding to 4000 and 8000U of cellulase kg1 of diet, directly included in the diet (BSG4 and BSG8 diets) or used to pre-treat the PF mixture of the control diet (PreBSG4 and PreBSG8 diets). Pre-treatment of PF with BSG-extract increased three-fold the dietary reducing sugars content and two-fold the antioxidant activity than the control diet. Cellulase and xylanase activities were highest in diets including BSG-extract directly added than pre-treated PF diets. These diets were fed to European seabass (IBW=22±1g) for 66days. Dietary supplementation with BSG-extract, mixed in the diet or used as a pre-treatment of PF, did not affect growth performance and whole-body composition (p0.05) of European seabass but increased feed efficiency (up to 18%; p
The authors thank UNICER, a soft-drink company (Porto, Portugal), for providing the brewer's spent grain used in this study. This work was supported by the project "SPO3- Development of innovative sustainable protein and omega-3 rich feedstuffs for aquafeeds, from local agro-industrial by-products" [reference POCI-010145-FEDER030377] funded by European Regional Development Fund (ERDF) and Portuguese Foundation for Science and Technology (FCT) and by strategic funding of FCT Technology through the projects UIDB/04423/2020 and UIDP/04423/2020. The H.F. was supported by FCT, MCTES, FSE, and UE grant [reference SFRH/BD/131219/2017] under the North Portugal Regional Operational Program (NORTE2020).
info:eu-repo/semantics/publishedVersion