Location: Bioenergy ResearchTitle: Miscanthus x giganteus xylooligosaccharides: Purification andfermentation Author
|Chen, Ming-hsu - University Of Illinois|
|Rausch, Kent - University Of Illinois|
|Tumbleson, M.e. - University Of Illinois|
|Signh, Vijay - University Of Illinois|
Submitted to: Carbohydrate Polymers
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/17/2015
Publication Date: 4/20/2016
Citation: Chen, M.H., Bowman, M.J., Cotta, M.A., Dien, B.S., Iten, L.B., Whitehead, T.R., Rausch, K.D., Tumbleson, M.E., Singh, V. 2016. Miscanthus x giganteus xylooligosaccharides: Purification and fermentation. Carbohydrate Polymers. 140:96-103. doi: 10.1016/j.carbpol.2015.12.052.
Interpretive Summary: There is a need for value-added co-products that can be conveniently produced by second generation ethanol facilities, which use cellulosic feedstocks, and that increase profit margins. Miscanthus x giganteus (MxG) is a warm season grass, which is adapted for growth in the Midwest that is considered a bioenergy crop because of its exceptional biomass production. In this study, we developed a process to extract out xylooligosaccharides (XOS). XOS are currently being marketed as a diet supplement that promotes the growth of beneficial gut microorganisms and good digestion. The process described is notable because the XOS produced was at commercial purity and generated from a novel biomass source. Furthermore, the cellulose fraction was left behind and would be suitable for conversion to ethanol. Finally, the XOS were compatible for the growth of two sample gut bacteria.
Technical Abstract: A procedure was developed to recover xylooligosaccharides (XOS) from Miscanthus x giganteus (MxG) hydrolyzates. MxG hydrolyzates were 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, MxG XOS, had 89.3% (w/w) total substituted oligosaccharides. Bifidobacterium adolescentis and Bifidobacterium catenulatum (health promoting bacteria) were cultured in vitro on MxG 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 MxG and commercial XOS cultures; and for B. catenulatum was 76.6 and 73.6%, respectively. The X2, X3 and X4 were almost utilized for both strains. Acetic and lactic acids were the major fermentation products of the XOS cultures.