Kinetic modeling of rhamnolipid production by Pseudomonas aeruginosa PAO1 including cell density-dependent regulation.
The production of rhamnolipid biosurfactants by Pseudomonas aeruginosa is under complex control of a quorum sensing-dependent regulatory network. Due to a lack of understanding of the kinetics applicable to the process and relevant interrelations of variables, current processes for rhamnolipid production are based on heuristic approaches. To systematically establish a knowledge-based process for rhamnolipid production, a deeper understanding of the time-course and coupling of process variables is required. By combining reaction kinetics, stoichiometry, and experimental data, a process model for rhamnolipid production with P. aeruginosa PAO1 on sunflower oil was developed as a system of coupled ordinary differential equations (ODEs). In addition, cell density-based quorum sensing dynamics were included in the model. The model comprises a total of 36 parameters, 14 of which are yield coefficients and 7 of which are substrate affinity and inhibition constants. Of all 36 parameters, 30 were derived from dedicated experimental results, literature, and databases and 6 of them were used as fitting parameters. The model is able to describe data on biomass growth, substrates, and products obtained from a reference batch process and other validation scenarios. The model presented describes the time-course and interrelation of biomass, relevant substrates, and products on a process level while including a kinetic representation of cell density-dependent regulatory mechanisms.
Institute of Process Engineering in Life Sciences, Section II: Technical Biology, Karlsruhe Institute of Technology (KIT), Engler-Bunte-Ring 1, 76131, Karlsruhe, Germany, marius.henkel@kit.edu.
Marius
M
Henkel
Anke
A
Schmidberger
Markus
M
Vogelbacher
Christian
C
Kühnert
Janina
J
Beuker
Thomas
T
Bernard
Thomas
T
Schwartz
Christoph
C
Syldatk
Rudolf
R
Hausmann
D002452:Cell Count; D006017:Glycolipids / Q000378:metabolism*; D008962:Models, Theoretical; D010938:Plant Oils / Q000378:metabolism; D011550:Pseudomonas aeruginosa / Q000378:metabolism*; D000074242:Sunflower Oil; D013997:Time Factors
D006017:Glycolipids; D010938:Plant Oils; D000074242:Sunflower Oil; C418382:rhamnolipid