title: Living bacteria in silica gels.
abstract: The encapsulation of enzymes within silica gels has been extensively studied during the past decade for the design of biosensors and bioreactors. Yeast spores and bacteria have also been recently immobilized within silica gels where they retain their enzymatic activity, but the problem of the long-term viability of whole cells in an inorganic matrix has never been fully addressed. It is a real challenge for the development of sol-gel processes. Generic tests have been performed to check the viability of Escherichia coli bacteria in silica gels. Surprisingly, more bacteria remain culturable in the gel than in an aqueous suspension. The metabolic activity of the bacteria towards glycolysis decreases slowly, but half of the bacteria are still viable after one month. When confined within a mineral environment, bacteria do not form colonies. The exchange of chemical signals between isolated bacteria rather than aggregates can then be studied, a point that could be very important for 'quorum sensing'.
authors.affiliation: Chimie de la Matière Condensée, Université Pierre et Marie Curie, 4 place Jussieu, 75252 Paris, France.
authors.forename: Nadine
authors.initials: N
authors.lastname: Nassif
authors.forename: Odile
authors.initials: O
authors.lastname: Bouvet
authors.forename: Marie
authors.initials: M
authors.lastname: Noelle Rager
authors.forename: Cécile
authors.initials: C
authors.lastname: Roux
authors.forename: Thibaud
authors.initials: T
authors.lastname: Coradin
authors.forename: Jacques
authors.initials: J
authors.lastname: Livage
mesh_terms: D002455:Cell Division; D004926:Escherichia coli / Q000254:growth & development / Q000302:isolation & purification* / Q000378:metabolism* / Q000648:ultrastructure; D005947:Glucose / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D020034:Silicone Gels; D013997:Time Factors
chemical_list: D020034:Silicone Gels; D005947:Glucose