Engineering Yeast Transcription Machinery for Improved Ethanol Tolerance and Production

TLDR

Global transcription machinery engineering reprograms gene transcription to elicit cellular phenotypes relevant to biotechnology. The study applies gTME to Saccharomyces cerevisiae to enhance glucose/ethanol tolerance, a critical trait for biofuel production. By mutagenizing the transcription factor Spt15p and selecting for growth, the authors identified dominant mutations that increased ethanol tolerance and improved glucose conversion. The improved phenotype arises from three SPT15 mutations (Phe177Ser, Tyr195His, Lys218Arg) and demonstrates that gTME can generate complex traits inaccessible to conventional methods.

Abstract

Global transcription machinery engineering (gTME) is an approach for reprogramming gene transcription to elicit cellular phenotypes important for technological applications. Here we show the application of gTME to Saccharomyces cerevisiae for improved glucose/ethanol tolerance, a key trait for many biofuels programs. Mutagenesis of the transcription factor Spt15p and selection led to dominant mutations that conferred increased tolerance and more efficient glucose conversion to ethanol. The desired phenotype results from the combined effect of three separate mutations in the SPT15 gene [serine substituted for phenylalanine (Phe 177 Ser) and, similarly, Tyr 195 His, and Lys 218 Arg]. Thus, gTME can provide a route to complex phenotypes that are not readily accessible by traditional methods.