Encapsulation of microbial cells into silica gel

This work deals with changes in microbial phenol degradation and cell proli feration caused by immobilization into silica gel. Mixed microbial culture and the yeast Candida tropicalis were immobilized in silica layers and piec es prepared by mixing of prepolymerized tetraethoxysilane with cell suspens ion. The phenol degradation rate of cells entrapped in silica gel was compa red with those immobilized into an organic polymer-polyurethane. The phenol degradation efficiency decreased in the following order: free cell suspens ion > cells entrapped into polyurethane foam similar to cells entrapped int o prepolymerized TEOS. Inside the silica there was no growth observed by op tical microscope. The immobilization of bacterium Pseudomonas species 2 int o silica gel, cells which co-metabolize PCBs with biphenyl, did not result in substantial change of intermediate concentration.