[Dependence of extracellular proteases synthesis on the growth phase of Pseudomonas fluorescens]

The aim of this work was to study the dependence of the synthesis of exocellular proteolytic enzymes on the growth phase of Pseudomonas fluorescens which was cultivated in media containing amino acids as a sole carbon source. In all of the studied cases, the proteolytic activity of the medium increased in parallel to the bacterial growth until the culture reached the stationary growth phase. Chloramphenicol added in the phase of intensive growth ceased the increase of the proteolytic activity of the medium without a noticeable delay in time. This fact indicates that the processes of translation and secretion of exoproteases occur virtually at the same time in the cell of P. fluorescens. The rate of degradation of exocellular proteolytic enzymes was shown to be insignificant in comparison to the rate of their synthesis. Therefore, the increase in the proteolytic activity of the medium directly reflects the rate of synthesis of exoproteases.