Submitted to: Society of Industrial Microbiology Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 8/15/2002
Publication Date: 8/15/2002
Citation: LOPEZ, M.J., NICHOLS, N.N., DIEN, B.S., MORENO, J., BOTHAST, R.J. SCREENING AND DISCOVERY OF MICROORGANISMS FOR INHIBITOR ABATEMENT IN TOXIC FERMENTATION SUBSTRATES. SOCIETY OF INDUSTRIAL MICROBIOLOGY ANNUAL MEETING. 2002. PAPER NO. 6-2. Interpretive Summary:
Technical Abstract: Agricultural residues have the potential to serve as a low-cost, abundant feedstock for production of fuel ethanol or other value-added products. A major technical challenge to producing ethanol is converting biomass into fermentable sugars. Conditions that promote the hydrolysis of glucan and xylans to free sugars, also promote the formation of toxic side-products (e.g., furfural, 5-hydroxymethylfurfural (HMF), and phenolics). Some of these compounds interfere with fermentations at concentrations as low as 10 mM. Biological treatment of hydrolysates for inhibitor abatement is a promising strategy for minimizing microbial stress during ethanol fermentations. Microorganisms with the ability to reduce inhibitors from corn stover hydrolysates were isolated from soils by enrichment culture using ferulic acid, furfural, or HMF as a sole carbon source. Six isolates were chosen and identified by sequencing a portion of the small subunit rDNA. Each reduced the level of toxic compounds by 50-100%. The most promising organism (C8), a fungus, was used to treat corn stover acid hydrolysates that contained 14 mM furfural and 3 mM HMF. C8 removed the compounds within approximately 30 hr.