Microchemostat-microbial continuous culture in a polymer-based, instrumented microbioreactor

Lab Chip. 2006 Jul;6(7):906-13. doi: 10.1039/b518396k. Epub 2006 Apr 20.


In a chemostat, microbial cells reach a steady state condition at which cell biomass production, substrates and the product concentrations remain constant. These features make continuous culture a unique and powerful tool for biological and physiological research. We present a polymer-based microbioreactor system integrated with optical density (OD), pH, and dissolved oxygen (DO) real-time measurements for continuous cultivation of microbial cells. Escherichia coli (E. coli) cells are continuously cultured in a 150 microL, membrane-aerated, well-mixed microbioreactor fed by a pressure-driven flow of fresh medium through a microchannel. Chemotaxisial back growth of bacterial cells into the medium feed channel is prevented by local heating. Using poly(ethylene glycol) (PEG)-grafted poly(acrylic acid) (PAA) copolymer films, the inner surfaces of poly(methyl methacrylate) (PMMA) and poly(dimethylsiloxane) (PDMS) of the microbioreactor are modified to generate bio-inert surfaces resistant to non-specific protein adsorption and cell adhesion. The modified surfaces of microbioreactor effectively reduce wall growth of E. coli for a prolonged period of cultivation. Steady state conditions at different dilution rates are demonstrated and characterized by steady OD, pH, and DO levels.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acrylic Resins / chemistry
  • Bacteriological Techniques / instrumentation*
  • Bacteriological Techniques / methods
  • Bioreactors*
  • Escherichia coli K12 / growth & development*
  • Escherichia coli K12 / metabolism
  • Hydrogen-Ion Concentration
  • Optics and Photonics
  • Oxygen / metabolism
  • Polyethylenes / chemistry
  • Polymethyl Methacrylate / chemistry


  • Acrylic Resins
  • Polyethylenes
  • (polyethylene-acrylic acid) copolymer
  • Polymethyl Methacrylate
  • Oxygen