Effects of protease inhibitors on growth of Serratia marcescens and Pseudomonas aeruginosa.

The growth inhibitory effects of chicken egg white ovomacroglobulin (ovoM) on Serratia marcescens and Pseudomonas aeruginosa were studied. The growth of protease-producing strains was greater than that of the strains producing little protease, and was inhibited in a dose-dependent manner by ovoM, a potent protease inhibitor. Dose-dependent enhancement of growth of strains of S. marcescens and P. aeruginosa that produce little protease was observed with the medium treated with proteases. These results indicate that extracellular proteases produced by the organisms augment their growth and that inhibition of the proteases results in suppression of growth.