title: Integrated electrochemical sensor array for on-line monitoring of yeast fermentations.
abstract: This paper describes the design, modeling, and experimental characterization of an electrochemical sensor array for on-line monitoring of fermentor conditions in both miniaturized cell assays and in industrial scale fermentations. The viable biomass concentration is determined from impedance spectroscopy. As a miniaturized electrode configuration with high cell constant is applied, the spectral conductivity variation is monitored instead of the permittivity variation. The dissolved oxygen concentration is monitored amperometrically using an ultramicroelectrode array, which is shown to have negligible flow dependence. pH is monitored using an ion-sensitive field effect transistor (ISFET), and a platinum thermistor is included for temperature measurements. All sensors were shown to be sufficiently accurate within the range relevant to yeast fermentations. The sensor array is shown to be very stable and durable and withstands steam-sterilization.
authors.affiliation: MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500AE Enschede, The Netherlands. e.e.krommenhoek@utwente.nl
authors.forename: E E
authors.initials: EE
authors.lastname: Krommenhoek
authors.forename: J G E
authors.initials: JG
authors.lastname: Gardeniers
authors.forename: J G
authors.initials: JG
authors.lastname: Bomer
authors.forename: X
authors.initials: X
authors.lastname: Li
authors.forename: M
authors.initials: M
authors.lastname: Ottens
authors.forename: G W K
authors.initials: GW
authors.lastname: van Dedem
authors.forename: M
authors.initials: M
authors.lastname: Van Leeuwen
authors.forename: W M
authors.initials: WM
authors.lastname: van Gulik
authors.forename: L A M
authors.initials: LA
authors.lastname: van der Wielen
authors.forename: J J
authors.initials: JJ
authors.lastname: Heijnen
authors.forename: And A
authors.initials: AA
authors.lastname: van den Berg
mesh_terms: D018533:Biomass; D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D004563:Electrochemistry; D004867:Equipment Design; D005285:Fermentation; D006863:Hydrogen-Ion Concentration; D007218:Industrial Microbiology; D008839:Microelectrodes; D010984:Platinum / Q000737:chemistry; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000378:metabolism*; D012680:Sensitivity and Specificity; D013696:Temperature; D013821:Thermometers; D014173:Transistors, Electronic
chemical_list: D010984:Platinum