Acetic acid (mM) Ethanol (g/L) Glycerol (g/L) Fermentation Efficiency (%) 0 41.04 ± 0.46 4.19 ± 0.045 88.82 20 43.58 ± 0.53 2.78 ± 0.03 93.53 50 34.45 ± 0.4 1.78 ± 0.2 78.31

Table 1: Ethanol, glycerol production (g/L) for S. cerevisiae NCYC2592 under control conditions (no acetic acid), 20 mM and 50 mM acetic acid. Fermentation efficiencies (%) were calculated using ethanol production-0.51 g/L theoretical maxima.