Short-term adaptation improves the fermentation performance of Saccharomyces cerevisiae in the presence of acetic acid at low pH.

The release of acetic acid due to deacetylation of the hemicellulose fraction during the treatment of lignocellulosic biomass contributes to the inhibitory character of the generated hydrolysates. In the present study, we identified a strain-independent adaptation protocol consisting of pre-cultivating the strain at pH 5.0 in the presence of at least 4 g L⁻¹ acetic acid that enabled aerobic growth and improved fermentation performance of Saccharomyces cerevisiae cells at low pH (3.7) and in the presence of inhibitory levels of acetic acid (6 g L⁻¹). During anaerobic cultivation with adapted cells of strain TMB3500, the specific ethanol production rate was increased, reducing the fermentation time to 48 %.