title: Encapsulation of living E. coli cells in hollow polymer microspheres of highly defined size.
abstract: Here, we report the preparation and characterization of hollow polymer microspheres based on the preprecipitation of porous calcium carbonate cores with an average size of 5 μm and their use for encapsulation of living microorganisms. The microspheres filled with individual living E. coli cells were prepared by layer-by-layer (LbL) deposition of different polyelectrolytes and proteins onto the porous calcium carbonate cores leading to the formation of matrix-like complexes of the compounds followed by calcium carbonate core dissolution using EDTA. Both the influence of the encapsulation process as well as of the used polyelectrolytes on the survival rate of the cells were determined by confocal laser scanning microscopy (CLSM) and microtiter plate fluorescence tests. After the encapsulation process ~40% of the cells were alive. Cultivation tests indicated that the lag phase of cells treated with polyelectrolytes increases and the encapsulated E. coli cells were able to produce green fluorescent protein inside the microcapsules.
authors.affiliation: Lehrstuhl für Chemie Biogener Rohstoffe, Technische Universität München, Schulgasse 16, 94315 Straubing, Germany.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Flemke
authors.forename: Matthias
authors.initials: M
authors.lastname: Maywald
authors.forename: Volker
authors.initials: V
authors.lastname: Sieber
mesh_terms: D004926:Escherichia coli / Q000737:chemistry* / Q000166:cytology / Q000648:ultrastructure*; D029968:Escherichia coli Proteins / Q000737:chemistry; D008863:Microspheres; D010316:Particle Size; D011108:Polymers / Q000737:chemistry*
chemical_list: D029968:Escherichia coli Proteins; D011108:Polymers