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Dissolved Organic Phosphorus Utilization by Phytoplankton Reveals Preferential Degradation of Polyphosphates Over Phosphomonoesters
- Source :
- Frontiers in Marine Science, Vol 5 (2018)
- Publication Year :
- 2018
- Publisher :
- Frontiers Media SA, 2018.
-
Abstract
- The nutritionally available pool of dissolved organic phosphorus (DOP) supports marine primary productivity in a range of ocean ecosystems but remains poorly resolved. Here, the relative lability of model phosphorous (P) compounds representing the major P(V) bond classes of marine DOP – phosphomonoesters (P-O-C) and phosphoanhydrides (P-O-P) – was assessed in diatom cultures of the genus Thalassiosira, as well as coastal field sites of the western North Atlantic. In diatom samples, maximum enzymatic hydrolysis rates revealed that the P-anhydride bonds of inorganic tripolyphosphate (3poly-P), followed by the P-anhydride bonds of adenosine 5’-triphosphate (ATP), were preferentially degraded relative to the P-monoesters adenosine 5’-monophosphate (AMP) and 4-methylumbelliferone phosphate (MUF-P). Consistent with these rate measurements, targeted proteomics analysis demonstrated that the underlying phosphatase diversity present in diatom samples was dominated by P-anhydride degrading enzymes (inorganic pyrophosphatases and nucleoside triphosphatases). Furthermore, biomass-normalized rates of ATP degradation were always suppressed under P-replete conditions in diatom cultures, but the effect of overall P availability on 3poly-P degradation was inconsistent among diatom strains, suggesting that inorganic polyphosphate (poly-P) degradation may persist irrespective of prevailing P levels in the marine environment. Indeed, the majority of field sites examined in the P-replete coastal western North Atlantic exhibited significantly higher maximum rates of inorganic poly-P hydrolysis relative to P-monoester hydrolysis, which was largely driven by phytoplankton dynamics. Based on these results, the possibility that P-anhydride utilization may contribute comparably or even more substantially than P-esters to community-level P demand, phytoplankton growth, and primary productivity should be considered.
- Subjects :
- 0301 basic medicine
lcsh:QH1-199.5
phosphoester
Ocean Engineering
lcsh:General. Including nature conservation, geographical distribution
Aquatic Science
Oceanography
03 medical and health sciences
Hydrolysis
chemistry.chemical_compound
Enzymatic hydrolysis
Phytoplankton
14. Life underwater
phosphorus stress
alkaline phosphatase activity
lcsh:Science
phosphoanhydride
Water Science and Technology
Global and Planetary Change
biology
Lability
Polyphosphate
fungi
polyphosphate
Phosphate
biology.organism_classification
030104 developmental biology
Diatom
chemistry
Environmental chemistry
dissolved organic phosphorus
lcsh:Q
Phosphomonoesters
Subjects
Details
- ISSN :
- 22967745
- Volume :
- 5
- Database :
- OpenAIRE
- Journal :
- Frontiers in Marine Science
- Accession number :
- edsair.doi.dedup.....4fc40f860a12462dab008fec2bc5fc02