Fig. 2: Effects of metabolic engineering in ethanol fermentation and the PDH bypass on pleuromutilin production.

a The ethanol fermentation pathway and the PDH bypass with the enzymes catalysing each reaction. The processes with the proteins indicated as blue box were blocked by gene deletion. Pleuromutilin production (b) and ethanol amount in the culture supernatant (c) in the indicated strains. The strains were cultured in MPY liquid medium at 30 °C for 5 days (b) and 1 day (c). Data are shown as means ± standard deviation (S.D.) with dot plot indicating each data of three independent experiments. *p < 0.05, **p < 0.01 by Student’s t-test compared to the WT strain. “N.D.” indicates “not detected”.