Presence and regulation of alkaline phosphatase activity in eukaryotic phytoplankton from the coastal ocean: Implications for dissolved organic phosphorus remineralization

• DOI: 10.4319/lo.2006.51.3.1381
• Publication Date: 2010-07-01T18:00:19Z
• Authors: Sonya T. Dyhrman; Kathleen C. Rutte...
• Keywords: 0106 biological sciences; 13. Climate action; 14. Life underwater; 01 natural sciences

The biologically important constituents of the dissolved organic phosphorus (DOP) pool, their bioavailability, and cycling in coastal systems are still poorly understood. Here we use enzyme alkaline phosphatase as a metric DOP bioavailability track activity this system. We observed (APA) >0.2-µm size fraction all surface samples tested during an Oregon coast cruise August 2001. Although there was not significant trend between APA phosphate concentration data set whole, chlorophyll a-normalized elevated at station with lowest inorganic (DIP) concentration. Activity also nutrient-addition experiments which nitrate amendments were used to force community drawdown DIP. These consistent regulation APA. A cell-specific assay revealed that percentage diatoms mimicked hydrolytic rate, but such for dinoflagellates. Further, dinoflagellate cells routinely higher than diatom activity. In nutrientaddition designed evaluate APA, taxa expressed less frequently dinoflagellates, they displayed tighter by DIP variability presence these eukaryotic phytoplankton indicates is potential driver nutrition species composition ocean.