title: Spatial distribution of viable cells immobilized in agar membranes.
abstract: The biocatalytic structures obtained by immobilizing microorganisms in planar gel slabs have been studied and modeled to better understand the dynamics of systems controlled by diffusion-reaction-growth couplings. The theoretical results give two kinds of information: the time evolution of the extra-membrane system due to the intra-membrane reactions which can easily be compared to experiments, and the intra-membrane behaviour which is mainly characterized by the concentration profiles. The steady state cell concentration profile is one of the most important elements of a system's behaviour. In addition to photographs taken at different depths in the membrane, we have developed an original, simple and reproducible technique for the experimental determination of the intra-membrane cell concentration profiles. The technique uses a home-made microtome to obtain gel slices, in which the cell concentration is determined using visible spectroscopy. By using this technique, we have shown a good agreement between the theoretical predictions and the experimental profiles, which validates the modeling.
authors.affiliation: URA 500 CNRS, Université de Rouen, Mont-Saint-Aignan, France.
authors.forename: J
authors.initials: J
authors.lastname: Lefebvre
authors.forename: J C
authors.initials: JC
authors.lastname: Vincent
mesh_terms: D000362:Agar; D015169:Colony Count, Microbial / Q000379:methods*; D004926:Escherichia coli / Q000166:cytology / Q000254:growth & development*; D008566:Membranes
chemical_list: D000362:Agar