Sol-gel as reaction matrix for bacterial enzymatic activity

Sol-gel process is a rapid growing field in material chemistry. The sol-gel matrices (SGM) are basically porous wet-gels or xerogels obtained by the h ydrolysis and condensation-polymerisation of metal and semimetal alkoxides, mainly SiO2 materials. The current study presents the uses of sol-gel glas s matrix (SGM) that allow direct entrapment of biomolecules within and at s urface, which can be utilized by microorganisms. This glass type is solid, transparent, porous and can be modulated to form a hydrophobic or hydrophil ic surface. In view of all these beneficial characteristics of SGM, prelimi nary data is presented on biofilm formed on thin films of SGM doped with a fluorochrome (fluorescein diacetate). The esterase/lipase activity of E. co li CN13 and K. oxytoca spp. biofilm grown on top of SGM thin film, doped wi th fluorescein diacetate, was detected at the level of a single cell by epi fluorescence microscopy. In view of these preliminary results, sol-gel glas s has a considerable potential as a variable matrix for single bacteria and biofilm investigation.