Immobilization of Saccharomyces uvarum onto solid carriers modifies their growth. When adsorbed onto glass or brick beads, synchronous yeast cycles and reduced generation times can be observed. The same phenomena take place when the cells are bound to the glass by glutaraldehyde. Synchronization of growth is also obtained with Schizosaccharomyces pombe amd Bacillus megaterium. These modifications do not result from an immobilization of cells in a particular state or from an interaction before linking.