The diel changes of the size fractionated alkaline phosphatase activity (APA) were studied in relation to several abiotic and biotic factors in Villerest reservoir (located on the Loire river, near the city of Roanne, France), bihourly during two days in July 1992 . The APA measured in this work exceeded considerably those reported in the literature, suggesting that dissolved mineral phosphorus was not available to microorganisms . At 1 m, the APA was primarily due to bacteria which actively assimilated organic P compounds released by photosynthetic algal metabolism . At 5, 10 and 20 m, the APA was predominantly algal . The high concentrations in SRP (soluble reactive phosphorus) would indicate that orthophosphates were not bioavailable . The reverse (i.e. availability to phytoplankton) would have resulted in undetectable levels of P-PO4 -due to the massive proliferation of algae in Villerest reservoir .
49
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.