scholarly journals Dissolved organic phosphorus regeneration by bacterioplankton: 5'-nucleotid-ase activity and subsequent phosphate uptake in a mesocosm enrichment experiment

1989 ◽  
Vol 58 ◽  
pp. 89-100 ◽  
Author(s):  
T Tamminen
Keyword(s):  
Phosphate Uptake ◽  
Organic Phosphorus ◽  
Dissolved Organic Phosphorus ◽  
Phosphorus Regeneration

Dissolved Organic Phosphorus Compounds: Do They Satisfy Planktonic Phosphate Demand in Summer?

1986 ◽  
Vol 43 (2) ◽  
pp. 343-350 ◽  
Author(s):  
Robert T. Heath
Keyword(s):  
Uptake Rate ◽  
Phosphate Uptake ◽  
Organic Phosphorus ◽  
Open Water ◽  
Eutrophic Lake ◽  
Phosphorus Compounds ◽  
Savannah River ◽  
Dissolved Organic Phosphorus ◽  
Western Basin ◽  
Nitrophenyl Phosphate

The rate of release of phosphate from dissolved organic phosphorus (DOP) compounds generally accounted for <1% of the phosphate uptake rate by seston in the open water of five diverse freshwater systems in summer. Surface water samples were taken during July and August 1984 from a eutrophic lake (East Twin Lake, OH), an acid bog lake (Triangle Bog Lake, OH), a freshwater estuarine marsh that empties into the western basin of Lake Erie (Old Woman Creek, OH), and two large mainstem reservoirs on the Savannah River (R. B. Russel Reservoir and Clarks Hill Lake, GA). In each of these, phosphatase hydrolysable phosphomonoesters (PME) often were the major fraction of DOP; phosphate release from photosensitive DOP was not detected in any of these systems at this time. The rate of release of phosphate from PME was calculated from Michaelis–Menten kinetics, and phosphatase activity was estimated spectrophotometrically using p-nitrophenyl phosphate as a model substrate. Radiometric analysis of the rate of phosphate uptake by seston showed that phosphate was sorbed to seston by at least two different processes. The total uptake rate by all uptake processes exhibited an apparent first-order dependence on the concentration of available phosphate. Typically, the velocity of uptake was 1–10 nmol∙L−1∙min−1, and the velocity of release from PME was 0.01–0.06 nmol∙L−1∙min−1.

scholarly journals Non-Conventional Metal Ion Cofactor Requirement of Dinoflagellate Alkaline Phosphatase and Translational Regulation by Phosphorus Limitation

2019 ◽  
Vol 7 (8) ◽  
pp. 232 ◽  
Author(s):  
Xin Lin ◽  
Chentao Guo ◽  
Ling Li ◽  
Tangcheng Li ◽  
Senjie Lin
Keyword(s):  
Alkaline Phosphatase ◽  
Metal Ion ◽  
Translational Regulation ◽  
Organic Phosphorus ◽  
Niche Differentiation ◽  
Phosphorus Limitation ◽  
Marine Phytoplankton ◽  
Phosphate Limitation ◽  
Dissolved Organic Phosphorus ◽  
Metal Cofactor

Alkaline phosphatase (AP) enables marine phytoplankton to utilize dissolved organic phosphorus (DOP) when dissolved inorganic phosphate (DIP) is depleted in the ocean. Dinoflagellate AP (Dino-AP) represents a newly classified atypical type of AP, PhoAaty. Despite While being a conventional AP, PhoAEC is known to recruit Zn2+ and Mg2+ in the active center, and the cofactors required by PhoAaty have been contended and remain unclear. In this study, we investigated the metal ion requirement of AP in five dinoflagellate species. After AP activity was eliminated by using EDTA to chelate metal ions, the enzymatic activity could be recovered by the supplementation of Ca2+, Mg2+ and Mn2+ in all cases but not by that of Zn2+. Furthermore, the same analysis conducted on the purified recombinant ACAAP (AP of Amphidinium carterae) verified that the enzyme could be activated by Ca2+, Mg2+, and Mn2+ but not Zn2+. We further developed an antiserum against ACAAP, and a western blot analysis using this antibody showed a remarkable up-regulation of ACAAP under a phosphate limitation, consistent with elevated AP activity. The unconventional metal cofactor requirement of Dino-AP may be an adaptation to trace metal limitations in the ocean, which warrants further research to understand the niche differentiation between dinoflagellates and other phytoplankton that use Zn–Mg AP in utilizing DOP.

scholarly journals Multi-pumping flow system for the determination of dissolved orthophosphate and dissolved organic phosphorus in wastewater samples

2006 ◽  
Vol 572 (1) ◽  
pp. 148-154 ◽  
Author(s):  
Carmen Pons ◽  
Ildikó V. Tóth ◽  
António O.S.S. Rangel ◽  
Rafael Forteza ◽  
Víctor Cerdà
Keyword(s):  
Flow System ◽  
Organic Phosphorus ◽  
Dissolved Organic Phosphorus ◽  
Wastewater Samples
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