Applied Microbiology and Biotechnology

, Volume 97, Issue 17, pp 7607–7616

Kinetic modeling of the time course of N-butyryl-homoserine lactone concentration during batch cultivations of Pseudomonas aeruginosa PAO1

  • Marius Henkel
  • Anke Schmidberger
  • Christian Kühnert
  • Janina Beuker
  • Thomas Bernard
  • Thomas Schwartz
  • Christoph Syldatk
  • Rudolf Hausmann
Biotechnological products and process engineering

DOI: 10.1007/s00253-013-5024-5

Cite this article as:
Henkel, M., Schmidberger, A., Kühnert, C. et al. Appl Microbiol Biotechnol (2013) 97: 7607. doi:10.1007/s00253-013-5024-5

Abstract

Quorum sensing affects the regulation of more than 300 genes in Pseudomonas aeruginosa, influencing growth, biofilm formation, and the biosynthesis of several products. The quorum sensing regulation mechanisms are mostly described in a qualitative character. Particularly, in this study, the kinetics of N-butyryl-homoserine lactone (C4-HSL) and rhamnolipid formation in P. aeruginosa PAO1 were of interest. In this system, the expression of the rhamnolipid biosynthesis genes rhlAB is directly coupled to the C4-HSL concentration via the rhl system. Batch cultivations in a bioreactor with sunflower oil have been used for these investigations. 3-oxo-dodecanoyl-homoserine lactone (3o-C12-HSL) displayed a lipophilic character and accumulated in the hydrophobic phase. Degradation of C4-HSL has been found to occur in the aqueous supernatant of the culture by yet unknown extracellular mechanisms, and production was found to be proportional to biomass concentration rather than by autoinduction mechanisms. Rhamnolipid production rates, as determined experimentally, were shown to correlate linearly with the concentration of autoinducer C4-HSL. These findings were used to derive a simple model, wherein a putative, extracellular protein with C4-HSL degrading activity was assumed (putative C4-HSL acylase). The model is based on data for catalytic efficiency of HSL-acylases extracted from literature (kcat/Km), experimentally determined basal C4-HSL production rates (qC4 - HSLbasal), and two fitted parameters which describe the formation of the putative acylase and is therefore comparatively simple.

Keywords

Rhamnolipid Biosurfactant Modeling Homoserine lactone Quorum sensing Pseudomonas aeruginosa 

Supplementary material

253_2013_5024_MOESM1_ESM.pdf (120 kb)
ESM 1(PDF 120 kb)

Copyright information

© Springer-Verlag Berlin Heidelberg 2013

Authors and Affiliations

  • Marius Henkel
    • 1
  • Anke Schmidberger
    • 2
  • Christian Kühnert
    • 3
  • Janina Beuker
    • 4
  • Thomas Bernard
    • 3
  • Thomas Schwartz
    • 2
  • Christoph Syldatk
    • 1
  • Rudolf Hausmann
    • 4
  1. 1.Institute of Process Engineering in Life Sciences, Section II: Technical BiologyKarlsruhe Institute of Technology (KIT)KarlsruheGermany
  2. 2.Institute of Functional Interfaces, Department Microbiology of Natural and Technical InterfacesKarlsruhe Institute of Technology (KIT)Eggenstein-LeopoldshafenGermany
  3. 3.Department Systems for Measurement, Control and Diagnosis (MRD)Fraunhofer Institute of Optronics, System Technologies and Image ExploitationKarlsruheGermany
  4. 4.Institute of Food Science and Biotechnology (150), Section Bioprocess Engineering (150k)University of HohenheimStuttgartGermany