ACTIVITY OF PHOSPHOHYDROLYTIC ENZYMES IN WATERS

Phosphorus occurs in mineral and organic forms in aquatic environments. Much of the available phosphorus resources occur in organic forms which are impossible to use directly by living organisms cytoplasmic membranes of microorganisms' cells transport almost exclusively orthophosphates. Biological decomposition of organic phosphorus combinations is one of the key stages of phosphorus cycle in surface waters. This process is possible due to existence of a group of phosphohydrolytic enzymes, such as: 5'-nucleotidase, endo- and exonucleases, phytase and phosphatases. Occurrence or activity of these enzymes was found in all components of plankton: bacteria, cyanobacteria, algae, fungi, single- and multicellular plankton animals. Activity of phosphohydrolytic enzymes directly affects productivity of aquatic ecosystems.