Sunday, May 3, 2009
3-46

Profiling of Oligosaccharides and Related Degradation Products Generated by AFEX Pretreatment of Lignocellulosic Biomass using LC/TOF-MS

Ramin Vismeh1, Shishir Chundawat2, James F. Humpula2, A. Daniel Jones3, and Bruce Dale2. (1) Department of Chemistry, Michigan State University, Chemistry department, Michigan State University, East Lansing, MI 48824, (2) Chemical Engineering and Materials Science, Michigan State University, Great Lakes Bioenergy Research Center (GLBRC), 3900 Collins Rd, Lansing, MI 48910, (3) Department of Chemistry, Department of Biochemistry and Molecular Biology, Michigan State University, Room 209, Biochemistry Building, East Lansing, MI 48824

Pretreatment of biomass helps enhance accessibility of recalcitrant cell wall sugar polymers to enzymatic processing. Characterization of chemical transformations of soluble oligosaccharides and other degradation products has remained elusive, but this information is critical for optimization of pretreatment conditions for maximizing enzymatic digestibility.

This study presents methods for quantitative profiling of oligosaccharides and related degradation products following Ammonia Fiber Explosion (AFEX) pretreatment of corn stover using different thermochemical severity conditions. Solid phase extraction conditions were optimized for enrichment of oligosaccharides using porous graphitized carbon, and LC/TOF MS using electrospray ionization with multiplexed collision induced dissociation (CID) was used to analyze the degradation products. The study revealed presence of oligosaccharides up to degree of polymerization (DP) 22, with and without various chemical modifications including acetylation. Multivariate statistical analyses highlighted variations in oligosaccharide content among untreated and different severity AFEX-treated corn stover. Chemical characterization of AFEX byproducts reveals the extent of oligosaccharide modification using different pretreatment conditions, and provides valuable information for process optimization.


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See more of The 31st Symposium on Biotechnology for Fuels and Chemicals (May 3-6, 2009)