Submitted to: Biotechnology for Fuels and Chemicals Symposium Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: May 9, 2004
Publication Date: May 9, 2004
Citation: Gorsich, S.W., Slininger, P.J., Liu, Z. 2004. Identification of Saccharomyces cerevisiae genes involved in furfural tolerance during fermentation. Biotechnology for Fuels and Chemicals Symposium Proceedings. May 9-12, 2004. Chattanooga, TN. Poster No. 2-42. p. 155. Technical Abstract: Lignocellulose is potentially a low-cost substrate for fermentative production of ethanol. However, to release sugars (glucose and xylose) from lignocellulose an acid hydrolysis procedure is often utilized. Unfortunately, growth inhibitors, furfural (2-furfuraldehyde) and 5-hydroxymethylfurfural (HMF) are also generated as degradation products of xylose and glucose, respectively. The desired end product, ethanol, at 8-12% is also a growth inhibitor. In addition to blocking cell growth, these inhibitors reduce ethanol yield. Engineering yeast to be more tolerant of these inhibitors is expected to increase ethanol yields and make bioconversion of lignocellulose more cost effective. Unfortunately, at the genetic level, little is known about how these inhibitors affect cell physiology. A Saccharomyces cerevisiae deletion library was screened to identify genes tolerant to furfural, HMF, and ethanol. We have identified two classes of genes. When compared to wild type, the first class enables better growth and the second class prevents or slows growth in the presence of one of the inhibitors. In both classes, identified genes are either uncharacterized or have previously been linked to known cellular processes. These include endocytosis, transcription, translation, stress response and vacuole, peroxisome, and plasma membrane maintenance. Glucose consumption, ethanol yield, and inhibitor metabolism were analyzed in deletion mutants and in strains overexpressing identified genes. Identified genes will be genetically engineered and introduced into industry yeast strains to evaluate their industrial potential.