Fig. 10

2,3-BDO fermentation by the YHI030 (evolved PDCΔ YSM046 expressing alsLpOp, aldcLlOp and BDH1) strain in pH-adjusted buffered medium under mild aerobic conditions. After pre-cultivation, 0.75 g-wet weight of cells were transferred into 50 mL of fresh SD selection medium containing 100 g L⁻¹ glucose and 500 mM MES (pH adjusted to 6.0) to give initial cell densities of 15 g-wet cell weight L⁻¹. Fermentation was conducted in Erlenmeyer flasks under mild aerobic conditions. The agitation speed was 50 rpm. A total of 300 g L⁻¹ of glucose was added to the fermentation culture in three equal doses (100 g L⁻¹ each, including the initially contained glucose). Glucose was added to the fermentation culture at 72 and 192 h. Data are presented as the mean ± standard deviation of three separate cultivations (n = 3 each)