Kinetic modeling of rhamnolipid production by Pseudomonas aeruginosa PAO1 including cell density-dependent regulation

Appl Microbiol Biotechnol. 2014 Aug;98(16):7013-25. doi: 10.1007/s00253-014-5750-3. Epub 2014 Apr 29.

Abstract

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Count
  • Glycolipids / metabolism*
  • Models, Theoretical*
  • Plant Oils / metabolism
  • Pseudomonas aeruginosa / metabolism*
  • Sunflower Oil
  • Time Factors

Substances

  • Glycolipids
  • Plant Oils
  • Sunflower Oil
  • rhamnolipid