title: Microchemostat-microbial continuous culture in a polymer-based, instrumented microbioreactor.
abstract: 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.
authors.affiliation: Department of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Ave. 66-566, Cambridge, MA 02139, USA.
authors.forename: Zhiyu
authors.initials: Z
authors.lastname: Zhang
authors.forename: Paolo
authors.initials: P
authors.lastname: Boccazzi
authors.forename: Hyun-Goo
authors.initials: HG
authors.lastname: Choi
authors.forename: Gerardo
authors.initials: G
authors.lastname: Perozziello
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Sinskey
authors.forename: Klavs F
authors.initials: KF
authors.lastname: Jensen
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry; D001431:Bacteriological Techniques / Q000295:instrumentation* / Q000379:methods; D019149:Bioreactors; D048168:Escherichia coli K12 / Q000254:growth & development* / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D055095:Optics and Photonics; D010100:Oxygen / Q000378:metabolism; D011095:Polyethylenes / Q000737:chemistry; D019904:Polymethyl Methacrylate / Q000737:chemistry
chemical_list: D000180:Acrylic Resins; D011095:Polyethylenes; C083316:(polyethylene-acrylic acid) copolymer; D019904:Polymethyl Methacrylate; D010100:Oxygen