X: Biomass concentration; S: Substrate concentration; DOT: Dissolved oxygen tension;
my: Specific growth rate;  F: Feed rate.

Dynamic simulation of a fedbatch process. After the batch phase (0-6 hrs) a constant feed of concentrated substrate (glycerol) was started. At about 8 hours the feed rate was doubled. See the effects of F on growth rate and DOT. The effect of F on S can not be seen here due to the scale but it is parallel to my.

The simulation does not represent a specific organism but the parameters are close to those of E. coli growing aerobically on glycerol.

A better but more elaborate model based on stoichiometric analysis is used in the SIMSPEC file fedbatch_Cmol.fig.