Submitted to: Meeting Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: August 1, 2004
Publication Date: July 27, 2004
Citation: Gorsich, S.W., Slininger, P.J., Liu, Z., Nichols, N.N., Dien, B.S. 2004. Identification of Saccharomyces cerevisiae genes involved in furfural tolerance during fermentation [abstract]. Proceedings of the Yeast Genetics and Molecular Biology. Abstract No. 166A, p. 104. Technical Abstract: Lignocellulose is a low-cost substrate for fermentative production of ethanol. However, to release sugars (glucose and xylose) from lignocellulose, an acid hydrolysis treatment is often utilized. Unfortunately, this treatment also generates growth inhibitors by degrading glucose and xylose to furfural and 5-hydroxymethylfurfural (HMF). These inhibitors cause cells to accumulate acetaldehyde and reduce ethanol yield. Engineering yeast to be more tolerant to these inhibitors is expected to increase ethanol yields and make bioconversion of lignocellulose more efficient. At the genetic level, little is known about the effect these inhibitors have on cell physiology. A Saccharomyces cerevisiae deletion library was screened to identify genes involved in furfural tolerance. This yielded two gene classes. The first class enables better growth while the second class prevents or slows growth in the presence of furfural, when compared to wildtype. Some identified genes are uncharacterized while others are linked to known cellular processes. These include endocytosis, transcription, translation, stress response, metabolite biosynthesis, and organelle function. These mutants were also analyzed for their ability to tolerate the other inhibitory furan produced during acid hydrolysis, HMF. Maximum inhibitor concentrations, for furfural and HMF, which allow identified mutants to grow were determined. Finally, glucose consumption, ethanol yield, and inhibitor metabolism were analyzed.