In the course of experimenting on the laboratory silification of algal cells and algal mats a series of organosilicon compounds was employed in attempts to simulate fossilization. These compounds provided a silica source for emplacement in the organic matrices of the algae. It was found that during the silicification process silicon acetate, triethoxysilane propylamine and tetraethylorthosilicate (tetraethoxysilane) yielded hydrolytic products which supported growth of microbes. Large numbers of microorganisms: several fungi, including yeast and an Aspergillus sp. and Pseudomonas aeruginosa were isolated from salt solutions containing these organosilicon compounds as the sole source of carbon. The rate of hydrolysis yielding silica for emplacement was not affected by growth of these microorganisms. The isolation and growth of pure cultures of P. aeruginosa on either triethylsilane propylamine or tetraethylorthosilicate is described.