Fig. 9.

2,3-BDO fermentation by the YHI030 (evolved PDCΔ YSM046 expressing alsLpOp, aldcLlOp and BDH1) strain. After pre-cultivation, 0.75 g-wet weight of cells were transferred into 50 mL of fresh SD selection media containing 25 (a), 50 (b) or 100 (c) g L⁻¹ glucose to give initial cell densities of 15 g-wet cell weight L⁻¹. Fermentation was conducted in small fermentation bottles with CO₂ gas outlets under anaerobic (oxygen-limited) conditions. Data are presented as the mean ± standard deviation of three separate cultivations (n = 3 each)