Using fluorogenic substrate analogs, the dynamics of extracellular enzyme activities (EEA)
of free and particle-bound a-glucosidase and aminopeptidase were investigated in mixed
cultures of marine phagotrophic nanoflagellates and bacteria. Flagellate growth on either
live or heatkilled bacteria led to an expression of free aminopeptidase activity with up to 94%
of total EEA found in the dissolved phase. No significant release of free a-glucosidase or
free aminopeptidase was found in flagellate-free bacterial cultures. Fed with heat-killed …

Using fluorogenic substrate analogs, the dynamics of extracellular enzyme activities of free
and particle-bound α-glucosidase and aminopeptidase were investigated in mixed cultures
of marine phagotrophic nanoflagellates and bacteria. The significance of the results is
discussed according to current theories on enzyme-catalyzed organic matter cycling.