simulation of an E. coli
batch/fedbatch process, started as a batch followed by
exponential/constant feed rate. Acetate is produced during the batch
phase. Therefore the initial glucose concentration should be so low
that it is exhausted before the acetate concentration becomes too
high. But then the biomass concentration is low. To further increase
the biomass concentration, an exponential feed was started with an
exponent (0.32 /h resulting in the same spec. growth rate) which
prevents overflow metabolism. The acetate is then quickly
re-assimilated and the biomass increases exponentially. To avoid
oxygen limitation, the feed rate is finally kept constant to
further increase the biomass concentration.
The oveflow metabolism model used is similar to the
yeast_model, with a maximum glucose uptake rate above which additional
glucose uptake is converted to acetate, which results in a maximum qO.
This model gives a reasonable fit to experimental data with E. coli
W3110 (Biotechnol. Prog. 1999, 15, 81−90). The inhibitory effect of
acetate has not been included in this model.