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

• Type: Article in International Scientific Journal
• Date: 2023

Authors

Filipe, D (Author) Other; Dias, M (Author) Other; Magalhaes, R (Author) Other; Fernandes, H (Author) Other; Salgado, J (Author) Other; Belo, I (Author) Other; Oliva Teles, A (Author) FCUP; Peres, H (Author) FCUP

Journal

Title: Fishes

Vol. 121

Final page: 90

Publisher: MDPI

Indexing

ISI Web of Knowledge - 0 Citations

Scopus - 1 Citation

Other information

Authenticus ID: P-00X-T54

DOI: 10.3390/fishes8020090

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

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 15