Fig. 2

Extracellular and intracellular glycerol concentrations for SCJ-VHG fermentations with S. cerevisiae industrial yeast strains PE-2 and CAT-1. Glycerol concentrations were quantified during a single 24-h fermentation cycle with 30 °Bx sugar cane juice, either non-supplemented (NS, square) or supplemented (SPP) with DAP (triangle) or urea (circle). Extracellular (ext) glycerol concentrations were measured in the fermentation broth after removal of the yeast biomass (a), and the biomass was used for estimation of the intracellular retention (int) of glycerol (b). Insert: The 24-h averages of the intracellular glycerol concentrations in the non-supplemented (NS) and DAP or urea supplemented 30 °Bx SCJ fermentations are compared. Results are presented as averages with standard deviation of three independent batch cultures. ****Indicates differences with statistical significance of P < 0.001