Miscanthus×giganteus xylooligosaccharides: Purification and fermentation

Area of Science:

• Biomass valorization
• Food science
• Microbiology

Background:

• Miscanthus×giganteus (M×G) is a sustainable lignocellulosic biomass source.
• Xylooligosaccharides (XOS) are prebiotics with potential health benefits.
• Efficient extraction and characterization of XOS from novel biomass sources are needed.

Purpose of the Study:

• To develop a procedure for recovering xylooligosaccharides (XOS) from Miscanthus×giganteus (M×G) hydrolyzate.
• To evaluate the prebiotic potential of M×G XOS by assessing its ability to support the growth of specific probiotic bacteria.
• To compare the fermentation products of M×G XOS with a commercial XOS source.

Main Methods:

• Autohydrolysis of M×G biomass to produce hydrolyzate.
• Activated carbon adsorption and stepwise ethanol elution for XOS-rich fraction isolation.
• Ion exchange resin treatments for purification of M×G XOS.
• In vitro culturing of Bifidobacterium adolescentis and Bifidobacterium catenulatum with M×G XOS and commercial XOS.
• Analysis of bacterial growth, substrate utilization, and fermentation products.

Main Results:

• A high-purity M×G XOS product was obtained, comprising 89.1% total substituted oligosaccharides (TSOS).
• Both Bifidobacterium adolescentis and Bifidobacterium catenulatum utilized M×G XOS, with B. adolescentis showing higher cell density and xylose consumption.
• Xylobiose (X2), xylotriose (X3), and xylotetraose (X4) were significantly consumed by both bacterial strains.
• Acetic and lactic acids were identified as the primary fermentation products.

Conclusions:

• The developed procedure effectively recovers purified XOS from M×G hydrolyzate.
• M×G XOS demonstrates prebiotic potential, supporting the growth of Bifidobacterium species.
• M×G XOS can be a viable alternative to commercial XOS for promoting gut health.