EN
This paper presents the results of investigatoins on activity of proteases, amylases and lipases synthetized by estuarine bacteria.The highest lavels of activitry of the enzymes studied were observed in bacteria from hypertrophic lake Jamno, the lowast in bacteria from eutrophic lake Lebsko.The activity of the enzymes displayed substantial seasonal fluctuations.The marked impact of pH and salinity on the level of the enzymatic activities was also noticed.