Glucuronosylated and linear xylooligosaccharides from Quinoa stalks xylan as potential prebiotic source for growth of Bifidobacterium adolescentis and Weissella cibaria

Abstract

Quinoa stalks glucuronoarabinoxylan (QSGAX) has been extracted by alkali and further utilized for production of two-types of xylooligosaccharides (XOs): i) enzymatically produced glucuronosylated-XOs (GXOs), and ii) a dilute acid produced mixture of non-substituted/substituted XOs of different degree of polymerization (DP). The respective mixtures were then separately evaluated as prebiotics by analysis of their consumption by two phylogenetically different potential probiotic bacterial strains (Bifidobacterium adolescentis ATCC15703 and Weissella cibaria strain 92), from which release of short chain fatty acids (SCFA) was also monitored. The GXOs mixture was produced using a glucuronosyl-requiring family 30 glycoside hydrolase (GH) Bacteroides ovatus (BoXyn30A), while the XOs mixture was produced by a 30 min acid treatment of QSGAX with H2SO4 [24.5 g/L] at 90 °C. B. adolescentis consumed both GXOs and XOs (DP 2–6), in both cases releasing acetate, lactate, propionate, formate and butyrate as metabolic products. W. cibaria only consumed XOs (DP 2–4), releasing acetate, lactate and minor amounts of butyrate. This is the first study reporting the ability of GXOs consumption by B. adolescentis and shows the potential of GXOs to selectively stimulate B. adolescentis, while XOs stimulated both types of potential probiotics (B. adolescentis ATCC15703 and W. cibaria strain 92).