The impact of transcription factors Znf1, Sip4, Adr1, Tup1, and Hap4 on xylose alcoholic fermentation in the engineered yeast Saccharomyces cerevisiae.

ABSTRACT

Lignocellulosic biomass is an attractive sustainable platform for fuel ethanol production. Xylose is a second after glucose most abounded sugar in lignocellulosic hydrolysates. Effective conversion of xylose to ethanol is one of key prerequisite for the development of an efficient conversion of biomass to ethanol. Engineered Saccharomyces cerevisiae strains are able to xylose fermentation. However, the yield and productivities of xylose fermentation remains lower in comparison with glucose fermentation. In this work, we studied impact of transcription factors Znf1, Sip4, Adr1, Tup1, and Hap4 on xylose catabolism. We have isolated znf1Δ, adr1Δ, tup1Δ and hap4Δ mutants, and strains overexpressing SIP4, ADR1 and HAP4 genes on the background of xylose-fermenting strain of S. cerevisiae aiming to explore involvement of these transcription factors in regulation of xylose growth and fermentation. It was shown that hap4Δ reveal 1.8-fold increase of ethanol production from xylose as compared to that of parental strain. The hap4Δ mutant accumulates 10.38 g l-1 of ethanol with an overall ethanol yield reaching 0.41 g g-1 of consumed xylose. While the other constructed strains revealed a decrease in ethanol production from this pentose.