Bioprocess Engineering

, Volume 4, Issue 5, pp 217–222

Modelling of the metabolism of Zymomonas mobilis growing on a defined medium

  • C. Posten

DOI: 10.1007/BF00369175

Cite this article as:
Posten, C. Bioprocess Eng. (1989) 4: 217. doi:10.1007/BF00369175


A structured model of Zymomonas mobilis is presented using fermentation data of a defined aspartate medium. After some remarks on the structure of the metabolism the model is derived by considering sub-models, e.g. balance equations, and by identifying the unknown parameters separately for each sub-model. Some results are the elemental composition of Zymomonas mobilis, a description of the substrate uptake during substrate limitation and the growth inhibition during substrate saturation. The results are shown as simulations and are discussed in relation to the inhibitory effect of ethanol on the bacterial cell.

List of Symbols

Asp mg/dm3


ctr g/(dm3 · h)

carbondioxide transfer rate

D dm3/h

dilution rate

eE,X g/g

content of element E in the biomass X


matrix of the elemental composition of r


vector of the elemental composition of the biomass


vector of modelling parameters

ki,s dm3/(g · h)

inhibition of substrate uptake

ki,NH dm3/g

inhibition of ammonia uptake

ki,yxs dm3/g

inhibition of yield factor

kred mmol/g

degree of reduction of the biomass

ks kg/m3

Michaelis-Menten parameter

P kg/m3

product, ethanol

pex kg/m3

ethanol in outlet gas

pi kg/m3

inorganic phosphate

Pyr kg/m3



vector of specific turn-over rates

rE g/(g · h)

spec. uptake rate of element E

\(r_{NH_3 , max} \) mg/(g · h)

max. ammonium uptake rate

\(r_{NH_3 , max,0} \) mg/(g · h)

max. ammonium uptake rate without ethanol influence

rs,max g/(g · h)

maximal specific substrate uptake

S kg/m3

substrate, glucose

S0 kg/m3

feed concentration

X kg/m3


Yx,s g/g

yield factor

μ h−1

specific growth rate

Copyright information

© Springer-Verlag 1989

Authors and Affiliations

  • C. Posten
    • 1
    • 2
  1. 1.Arbeitsbereich Regelungstechnik und SystemdynamikTU Hamburg-HarburgFRG
  2. 2.Hamburg 90FRG

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