Improved ethanol production at high temperature by consolidated bioprocessing using Saccharomyces cerevisiae strain engineered with artificial zinc finger protein

In this work, the consolidated bioprocessing (CBP) yeast Saccharomyces cerevisiae MNII/cocδBEC3 was transformed by an artificial zinc finger protein (AZFP) library to improve its thermal tolerance, and the strain MNII-AZFP with superior growth at 42°C was selected. Improved degradation of acid swollen cellulose by 45.9% led to an increase in ethanol production, when compared to the control strain. Moreover, the fermentation of Jerusalem artichoke stalk (JAS) by MNII-AZFP was shortened by 12h at 42°C with a concomitant improvement in ethanol production. Comparative transcriptomics analysis suggested that the AZFP in the mutant exerted beneficial effect by modulating the expression of multiple functional genes. These results provide a feasible strategy for efficient ethanol production from JAS and other cellulosic biomass through CBP based-fermentation at elevated temperatures.