In vitro evaluation of the interaction between exogenous carbohydrases produced by solid-state fermentation of brewers’ spent grain and digestive enzymes

Abstract

[Excerpt] Introduction The presence of non-starch polysaccharides (NSP) in most plant feedstuffs (PF) has been associated with adverse effects on carnivorous fish nutrient digestibility and, ultimately, on growth and health. The lack of enzymatic machinery and well-developed microbiota in the digestive tract of carnivorous fish for processing NSP are possible causes for such effects. A promising nutritional strategy to improve nutrient digestibility of plant-based diets is the use of exogenous enzymes (e.g. carbohydrases, proteases) as feed additives. Solid-state fermentation (SSF) is an eco-friendly and cost-effective biotechnology process that allows converting inexpensive agro-industrial by-products into added-value products such as carbohydrases. As a low-cost and lignocellulosic by-product of the brewing industry, brewery spent grain (BSG) is an attractive substrate for microbial enzyme production by SSF. The present study was designed to assess the potential of a carbohydrase enzyme extract obtained by SSF to release total amino acids (AA) and monosaccharides (pentoses) from plant-based diets in an in vitro gastrointestinal model with enzyme extracts of European sea bass (Dicentrarchus labrax).[...]