Mechanizmy i kontrola mikrobiologicznych procesów degradacjii utylizacji materii organicznej w ekosystemach jeziornych o różnym stopniu eutrofizacji wód

The report presents the results of a study of phytoplankton primary and bacterial secondaryproduction, and enzymatic activities in surface lake water sampled from five lakes (MazurianLake District, Poland) of different degrees of eutrophication during summer stratification period.The rates of bacterial secondaiy production correlated postively to phytoplankton primary production and both processes related to the trophic status of the lakes. The magnitude of bacterialproduction was strongly dependent on bacterial enzymatic degradation of polymeric organicmatter. Through the production of hydrolytic enzymes (aminopeptidase, [3-glucosidase, lipase),bacteria were capable of utilizing a variety of polymeric substrates, otherwise not utilizable,which predominated in lake water. The authors also propose and discuss a model of flow oforganic matter in aquatic ecosystems and a role of bacteria and phages in this process.