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Nancy N. Nichols,
nicholnn@ncaur.usda.gov1, C. Kevin Chambliss,
Kevin_Chambliss@baylor.edu2, G. Peter van Walsum,
GPeter_van_Walsum@baylor.edu3, Lekh Nath Sharma2,
and Bruce S. Dien, dienb@mail.ncaur.usda.gov1. (1)
Fermentation Biotechnology Research Unit, USDA-Agricultural Research
Service, National Center for Agricultural Utilization Research, 1815
N. University Street, Peoria, IL 61604, (2) Department of Chemistry
and Biochemistry, Baylor University, P.O. Box 97348, Waco, TX 76798,
(3) Department of Environmental Studies, Baylor University, P.O. Box
97266, Waco, TX 76798-7266
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| An important barrier to commercialization of the
biomass-to-ethanol process is the presence of substances that are toxic
to fermenting microorganisms. Organic acids, aldehydes, phenolics, and
furan compounds arise during acid hydrolysis of lignocellulosic biomass
and may cause slow or failed fermentations. We have developed a
bioremediation strategy to detoxify biomass sugars prior to
fermentation. Microorganisms were enriched from soil for their capacity
to metabolize ferulic acid, furfural, and 5-hydroxymethylfurfural and
for their ability to grow in acid hydrolysate of corn stover. The best
isolate for removing inhibitors was a fungus, Coniochaeta ligniaria
NRRL 30616. Analytical extraction of corn-stover hydrolysate followed by
HPLC and LC-MS analyses has been used to quantitate a variety of
aromatic acid, aliphatic acid, and aldehyde and phenolic degradation
products. This approach was used to follow the removal of several
important compounds during inhibitor abatement. |