Microbial enzymatic degradation of tamarind galactoxyloglucan and wheat arabinoxylan by a porcine faecal inoculum

This study investigated the enzymatic degradation of solubilised tamarind galactoxyloglucan (GXG) and wheat arabinoxylan (AX), as models for abundant polysaccharides in the primary cell walls of fruits/vegetables and cereal grains, respectively. Using a porcine faecal inoculum, it was demonstrated that the microbial consortia produced surface-located endo-β-xyloglucanase and endo-β-xylanase, to enable the degradation of these polymers into oligosaccharides, close to the microbial surface. Subsequently, these oligosaccharides were completely degraded into monosaccharides by exo-degrading enzymes located both within and on the microbial cell wall, while no enzymatic activities were detected in the cytoplasm. This study reveals a competitive utilisation of GXG and AX by a porcine faecal microbiota, and contributes to our understanding of the mechanisms by which fibre polysaccharides are degraded by the gut microbial community.Graphical abstract
Source: Bioactive Carbohydrates and Dietary Fibre - Category: Food Science Source Type: research