Submitted to: Applied Biochemistry and Biotechnology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 20, 2004
Publication Date: April 1, 2005
Citation: Nichols, N.N., Dien, B.S., Guisado, G.M., Lopez, M.J. 2005. Bioabatement to remove inhibitors from biomass-derived sugar hydrolysates. Applied Biochemistry and Biotechnology. 121-124:379-390. Interpretive Summary: Additional value could be obtained from agricultural crops, if the sugars present in agricultural waste materials (biomass) could be efficiently converted to products such as fuel ethanol. Use of crop residues to make value-added products is limited in part by the presence of substances, formed during acid pretreatment of biomass, that are toxic to the microbes used to carry out fermentation reactions. We discovered a new fungus that can be used to remove the inhibitory chemicals and incorporated its use into a fermentation scheme for converting biomass to ethanol. Current methods used to remove inhibitory compounds rely on chemical treatment and, in general, produce wastes and/or are too costly. The biological abatement method described here would be relatively inexpensive, use less water, and would generate little or no chemical waste. This work will benefit agricultural producers by adding value to crops. Producers of ethanol and other value-added chemicals will have an improved method to remove inhibitors from biomass-derived sugars.
Technical Abstract: Coniochaeta ligniaria NRRL30616, an Ascomycete that metabolizes furfural and 5-hydroxymethylfurfural, is a unique species that may be useful for detoxifying biomass sugars. NRRL30616 and 23 related strains were screened for the ability to metabolize furans and grow in dilute acid hydrolysate of corn stover. NRRL30616 was the best strain for removal of inhibitors from hydrolysate, and abatement of hydrolysate by inoculation with the strain allowed subsequent yeast fermentation of cellulose to ethanol. Bioabatement may be a method for removal of inhibitory compounds from lignocellulose hydrolysates, that could be incorporated into a scheme for fermentation of ethanol from cellulose.