Fig. 5

Fermentation of glucose or xylose to butyrate in mineral salt medium by E. coli strain LW393. Fermentations were in AM1 medium with additional trace metals at 37 °C and pH 7.0. N₂ was sparged through the cultures at 7 ml min⁻¹. a Glucose; b xylose; c glucose + yeast extract (5 g l⁻¹); d xylose + yeast extract (5 g l⁻¹). Other experimental conditions are the same as listed in Fig. 4