Linear Growth Kinetics of Plaque-forming Streptococci in the Presence of Sucrose

SUMMARY Growth of intact plaques of dextran-forming strain sl-1 was linear both on a dry weight and DNA basis. Growth of broth cultures of dextran-forming strains sl-1 and e-49 was linear with sucrose but exponential with other sugars; non dextran-forming strains 4m4 and jr8lg grew exponentially with all sugars tested. When dextranase was added to slowly growing cultures of dextran-forming strains sl-1 and e-49, growth became rapid. Linear growth of strains sl-1 and e-49 with sucrose is ascribable to extracellular dextran synthesized by the organisms.