Submitted to: Biotechnology for Fuels and Chemicals Symposium Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: May 12, 2004
Publication Date: May 12, 2004
Citation: Nichols, N.N., Dien, B.S., Guisado, G.M., Lopez, M.J. 2004. Use of the ascomycete coniochaeta ligniaria to remove inhibitors from biomass-derived sugars [abstract]. Biotechnology For Fuels And Chemicals Symposium. Paper No. 2-10. Technical Abstract: Use of agricultural residues as feedstock for production of fuels and chemicals is limited in part by the presence of inhibitory substances in the sugar streams obtained from the residues. Conditions that promote the hydrolysis of glucan and xylans to free sugars also promote formation of compounds including furfural, 5-hydroxymethylfurfural (HMF), acetate, and phenolics that may interfere with fermentations. Biological treatment of hydrolysates for inhibitor abatement is a promising strategy for abatement of microbial inhibitors in ethanol fermentations of biomass sugars. We isolated a fungus from soil that metabolizes many of the inhibitory compounds and reduces the concentration of furfural, HMF, and acetate in corn stover hydrolysates essentially to zero. The fungus, Coniochaeta ligniaria strain NRRL30616, was used to remove inhibitors from hydrolyzed corn stover, followed by saccharification and fermentation to ethanol with Saccharomyces cerevisiae. Additional strains of the same and related species were evaluated for the ability to metabolize furans, sugars, and phenolics. The isolates most closely related to NRRL30616 could metabolize furfural and HMF, and a subset of those could grow in corn stover hydrolysate. C. ligniaria is a unique species that may be useful for detoxifying biomass-derived sugar streams.