Improvement of the Nutraceutical Profile of Brewer’s Spent Grain after Treatment with Trametes versicolor

• Published in: Microorganisms (Basel) 2022-11, Vol.10 (11), p.2295
• Main Authors: Zeko-Pivač, Anđela, Bošnjaković, Anja, Planinić, Mirela, Parlov Vuković, Jelena, Novak, Predrag, Jednačak, Tomislav, Tišma, Marina
• Format: Article
• Language: English
• Subjects: Animal feed; Biological treatment; Breweries; brewer’s spent grain; Cellulase; Cellulose; Chemical composition; Dietary minerals; Enriched feed; enzyme cocktail; Enzymes; Feeds; Fermentation; Functional foods & nutraceuticals; Fungi; Glucosidase; Grain; Hemicellulose; Invertebrates; Laboratories; Laccase; Lignin; Lignin peroxidase; Ligninolytic enzymes; Lignocellulose; Manganese; Manganese peroxidase; Microorganisms; Moisture content; Nutrient content; Nutrition; Nutritive value; Peroxidase; phenolic compounds; Polyphenols; Raw materials; Solid state fermentation; Substrates; Sugar; Trametes versicolor; Xylanase; β-Glucosidase
• ISSN: 2076-2607; 2076-2607
• DOI: 10.3390/microorganisms10112295

Brewer’s spent grain (BSG) is an important secondary raw material that provides a readily available natural source of nutraceuticals. It finds its largest application as animal feed and part of the human diet, while the future perspective predicts an application in the production of value-added products. In order to investigate a sustainable BSG treatment method, two BSG samples (BSG1 and BSG2) were evaluated as substrates for the production of hydrolytic (xylanase, β-glucosidase and cellulase) and lignolytic enzymes (laccase, manganese peroxidase and lignin peroxidase) by solid-state fermentation (SSF) with Trametes versicolor while improving BSG nutritional value. The biological treatment was successful for the production of all hydrolytic enzymes and laccase and manganese peroxidase, while it was unsuccessful for the production of lignin peroxidase. Because the two BSGs were chemically different, the Trametes versicolor enzymes were synthesized at different fermentation times and had different activities. Consequently, the chemical composition of the two BSG samples at the end of fermentation was also different. The biological treatment had a positive effect on the increase in protein content, ash content, polyphenolic compounds, and sugars in BSG1. In BSG2, there was a decrease in the content of reducing sugars. Cellulose, hemicellulose, and lignin were degraded in BSG1, whereas only cellulose was degraded in BSG2, and the content of hemicellulose and lignin increased. The fat content decreased in both samples. The safety-related correctness analysis showed that the biologically treated sample did not contain any harmful components and was therefore safe for use in nutritionally enriched animal feed.