Miscanthus×giganteus xylooligosaccharides: Purification and fermentation

Abstract

A procedure was developed to recover xylooligosaccharides (XOS) from Miscanthus×giganteus (M×G) hydrolyzate. M×G hydrolyzate was prepared using autohydrolysis, and XOS rich fractions were acquired using activated carbon adsorption and stepwise ethanol elution. The combined XOS fractions were purified using a series of ion exchange resin treatments. The end product, M×G XOS, had 89.1% (w/w) total substituted oligosaccharides (TSOS) composed of arabinose, glucose, xylose and acetyl group. Bifidobacterium adolescentis and Bifidobacterium catenulatum (health promoting bacteria) were cultured in vitro on M×G XOS and a commercial XOS source, which was used as a comparison. B. adolescentis grew to a higher cell density than B. catenulatum in both XOS cultures. Total xylose consumption for B. adolescentis was 84.1 and 84.8%, respectively for M×G and commercial XOS cultures; and for B. catenulatum was 76.6 and 73.6%, respectively. The xylobiose (X2), xylotriose (X3) and xylotetraose (X4) were almost utilized for both strains. Acetic and lactic acids were the major fermentation products of the XOS cultures.

Keywords: Acetic acid; Acetic acid (PubChem CID: 176); Autohydrolysis; D-Glucose (PubChem CID: 5793); Fermentation; L-Arabinose (PubChem CID: 5460291); Lactic acid; Lactic acid (PubChem CID: 612); Miscanthus×giganteus; Xylobiose (PubChem CID: 439538); Xylohexaose (PubChem CID: 74539951); Xylooligosaccharides; Xylopentaose (PubChem CID: 10146542); Xylotetraose (PubChem CID: 10230811); Xylotriose (PubChem CID: 10201852); d-Xylose (PubChem CID: 135191).