Overexpression of a truncated form of the MSN2 gene enhances the initial rate of ethanol production in an industrial fuel-ethanol Saccharomyces cerevisiae strain

Augusto Bücker,Boris Stambuk,Júlio Cézar Espírito Santo,Davi Ludvig Gonçalves

doi:10.1186/1753-6561-8-s4-p126

Augusto Bücker, Boris Stambuk + Show 2 more

Open Access

https://doi.org/10.1186/1753-6561-8-s4-p126

Copy DOI

Abstract

Background The yeast strain CAT-1 isolated from a Brazilian fuelethanol plant (Babrzadeh et al. 2009) is one of the most common strain used nowadays due to its very efficient fermentation capacity, especially at high sugar concentrations and under the stressful industrial conditions. Since the transcription factor genes MSN4, MSN2, YAP1 and HSF1 of tolerant yeast strains are highly expressed under ethanol stress [1], we generated a CAT-1 derived strain named ATT-6 that overexpresses a truncated form of the transcription activator Msn2 through genomic engineering and analyzed the ethanol stress tolerance and fermentation capacity of this modified strain.

Highlights

The yeast strain CAT-1 isolated from a Brazilian fuelethanol plant (Babrzadeh et al 2009) is one of the most common strain used nowadays due to its very efficient fermentation capacity, especially at high sugar concentrations and under the stressful industrial conditions
Following the procedure described by Petracek and Longtine [2], for the construction of a yeast strains overexpressing a truncated form of the MSN2 gene, a DNA fragment containing the Kanr which confers resistance to G418, flanked by LoxP regions and the constitutive PADH1 promoter, was integrated into the genomic locus of the MSN2 gene of CAT-1, deleting the N-terminal region of the protein
We used high sucrose concentration (200 g/L) to expose yeast cells to high ethanol concentrations, caused by the initially added ethanol (12-16%), and by the ethanol produced during fermentation

Summary

Introduction

The yeast strain CAT-1 isolated from a Brazilian fuelethanol plant (Babrzadeh et al 2009) is one of the most common strain used nowadays due to its very efficient fermentation capacity, especially at high sugar concentrations and under the stressful industrial conditions. Methods Following the procedure described by Petracek and Longtine [2], for the construction of a yeast strains overexpressing a truncated form of the MSN2 gene, a DNA fragment containing the Kanr which confers resistance to G418 (geneticin), flanked by LoxP regions and the constitutive PADH1 promoter, was integrated into the genomic locus of the MSN2 gene of CAT-1, deleting the N-terminal region (first 48 amino acids) of the protein. The effect of 12-16% (v/v) ethanol addition on cell growth of the strain was evaluated in 96-well plates using a Tecan GENios microplate reader at 30°C and 110 rpm.

Results

Conclusion