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ARS Home » Midwest Area » Peoria, Illinois » National Center for Agricultural Utilization Research » Bioenergy Research » Research » Publications at this Location » Publication #313698
Title: Bioabatement with hemicellulase supplementation to reduce enzymatic hydrolysis inhibitors

Author
item CAO, GUANGLI - Purdue University
item XIMENES, EDUARDO - Purdue University
item Nichols, Nancy
item Frazer, Sarah
item KIM, DAEHWAN - Purdue University
item Cotta, Michael
item LADISCH, MICHAEL - Purdue University

Submitted to: Bioresource Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/10/2015
Publication Date: 8/1/2015
Publication URL: http://handle.nal.usda.gov/10113/62148
Citation: Cao, G., Ximenes, E., Nichols, N.N., Frazer, S.E., Kim, D., Cotta, M.A., Ladisch, M. 2015. Bioabatement with hemicellulase supplementation to reduce enzymatic hydrolysis inhibitors. Bioresource Technology. 190:412-415.

Interpretive Summary: Enzymes are a significant cost of making renewable fuels and chemicals from biomass, so improving the activity of enzymes used in the process could decrease the input cost for biofuels. In making renewable fuels and chemicals, cellulose from plants is first converted to glucose by enzymes termed cellulases. However, the cellulase enzymes are inhibited by a number of substances present in biomass slurries. To improve cellulase activity, we used a microbe to remove inhibitors and further showed that removal of short sugar chains (xylo-oligomers) also boosted cellulase activity and improved conversion of cellulose to glucose 1.2- to 1.4-fold. These results will benefit producers of renewable fuels and chemicals by decreasing the cost of enzymes used for production of biofuels.

Technical Abstract: Removal of inhibitory compounds by bioabatement, combined with xylan hydrolysis, enables effective cellulose hydrolysis of pretreated corn stover, for fermentation of the sugars to fuel ethanol or other products. The fungus Coniochaeta ligniaria NRRL30616 eliminates most enzyme and fermentation inhibitors from liquid hot water-pretreated corn stover hydrolysates. However, addition of hemicellulases after bioabatement but before enzymatic hydrolysis of cellulose is needed to achieve high glucose yields (about 20% higher compared to non-treated samples). This work presents the mechanisms by which supplementation of the fungus with hemicellulase enzymes enables maximal conversion, and confirms the inhibitory effect of xylo-oligosaccharides in corn stover hydrolysates once the dominant inhibitory effect of phenolic compounds is removed.