Whole-cell encapsulation, in sol-gels

Whole-cell encapsulation in sol-gels and their applications... 

WHOLE-CELL ENCAPSULATION IN SOL-GELS AND THEIR APPLICATIONS... 

One of the major advances in the field of sol-gel materials would be the possibility to trap whole cells within porous silica matrices and a whole chapter of this book is devoted to the encapsulation of eukaryotic cells (fungi, mammalian cells, etc.). Therefore we shall, focus our discussion on prokaryotic cells (bacteria). Their metabolic activity can be used for a large variety of processes in food industry, waste treatment and the prodnction of chemicals or drugs. 

Actually, the viability of whole cells in a sihca matrix is a crucial point for sol-gel to compete with usual encapsulation processes in polymer matrices. However very few experiments have been performed to check the long-term viability of trapped cells after encapsulation. Experiments performed with Pseudomonas sp. bacteria showed that they retain their ability to metabolize atrazine, a widely used herbicide. Entrapped cells lose much of their activity upon immobilization but partial activity could be restored by adding nutrients suggesting that bacteria may remain aUve, at least for some time (Rietti-Shati, 1996). 

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