[Effect of nalidixic acid and mitomycin C on growth and biosynthesis of extracellular proteins by Serratia marcescens].

The effect of various concentrations of nalidixic acid and mitomycin C on the dynamics of growth of Serratia marcescens and synthesis of endonuclease and other extracellular enzymes by it was studied. The synthesis of extracellular endonuclease was induced during inhibition of the cell division under the effect of nalidixic acid and mitomycin C. The induction of the endonuclease synthesis preceded the start of the division of the resistant cells which overcame the phase of the population retarded growth. The fermentation broth of the cells exposed to nalidixic acid and mitomycin C contained increased amounts of protein and possessed higher activities of chitin phosphodiesterase and phosphatase. It was shown by PAAG-electrophoresis with sodium dodecyl sulphate that the pattern of the extracellular proteins of S. marcescens undergone quantitative and qualitative changes under the effect of nalidixic acid and mitomycin C.