Phosphatases in Lake Water: Characterization of Enzymes from Phytoplankton and Zooplankton by Gel Filtration

Sephadex gel filtration was used to characterize phosphomonoesterases in two small takes in northern Sweden. Two fractions, here termed phosphatase A and phosphatase B, were found both as free enzymes and associated with seston. The activity of phosphatase A was correlated with the presence of algal biomass. Phosphatase B, on the other hand, was derived from zooplankton. Phosphate served as an effective inhibitor of phosphatase A but had no such effect on phosphatase B. Both fractions had pH optima between 6.5 and 7.0.