Increasing the bioethanol yield in the presence of furfural via mutation of a native strain of Saccharomyces cerevisiae.

High ethanol yield is a desired property of industrial yeast strains. A significant problem in fermentative conversion of lignocellulosic materials to ethanol is the formation of furfural and hydroxymethylfurfural (HMF), which are formed during acid hydrolysis of lignocellulose. Furfural has been known to create strong inhibition in metabolism of the yeast Saccharomyces cerevisiae. In this article, the result of random mutagenesis of a native strain of S. cerevisiae by ultra violet (UV) light and nitrous acid is presented. By screening the cells in the presence of furfural, a potent mutant was selected which produced 36.7% more bioethanol than the parent strain, in the presence of 0.2% (v/v) furfural.   Key words: Bioethanol, furfural, mutation, nitrous acid, Saccharomyces cerevisiae PTCC 5315, UV radiation.