Fig. 1

R. eutropha H16 growth under different conditions. The initial growth medium pH was 7.0. a Biomass formation, g L⁻¹, was determined after 48 h bacterial growth; b specific growth rate (µ); c pH changes during bacterial growth for 48 h; FN Fructose–Nitrogen, FGN Fructose–Glycerol–Nitrogen, GN Glycerol–Nitrogen, GFN Glycerol–Fructose–Nitrogen, BSGH brewery spent grains hydrolysate. 3 mM DTT (DL-dithiothreitol) and 1 mM ferricyanide (Fer) were supplemented as indicated. Average data of three independent measurements are presented with standard errors