TY - JOUR
T1 - Organic Phosphorus Scavenging Supports Efficient Growth of Diazotrophic Cyanobacteria Under Phosphate Depletion
AU - Rabouille, Sophie
AU - Tournier, Lauralie
AU - Duhamel, Solange
AU - Claquin, Pascal
AU - Crispi, Olivier
AU - Talec, Amélie
AU - Landolfi, Angela
AU - Oschlies, Andreas
N1 - Funding Information:
This work was supported by the French National program LEFE (Les Enveloppes Fluides et l’Environnement). SD was funded by NSF grants OCE 1434916 and 1737083.
Publisher Copyright:
Copyright © 2022 Rabouille, Tournier, Duhamel, Claquin, Crispi, Talec, Landolfi and Oschlies.
PY - 2022/3/25
Y1 - 2022/3/25
N2 - Considering the reported significant diazotrophic activities in open-ocean regions where primary production is strongly limited by phosphate, we explored the ability of diazotrophs to use other sources of phosphorus to alleviate the phosphate depletion. We tested the actual efficiency of the open-ocean, N2-fixer Crocosphaera watsonii to grow on organic phosphorus as the sole P source, and observed how the P source affects the cellular C, N, and P composition. We obtained equivalent growth efficiencies on AMP and DL-α-glycerophosphate as compared with identical cultures grown on phosphate, and survival of the population on phytic acid. Our results show that Crocosphaera cannot use all phosphomonoesters with the same efficiency, but it can grow without phosphate, provided that usable DOP and sufficient light energy are available. Also, results point out that organic phosphorus uptake is not proportional to alkaline phosphatase activity, demonstrating that the latter is not a suitable proxy to estimate DOP-based growth yields of organisms, whether in culture experiments or in the natural environment. The growth parameters obtained, as a function of the P source, will be critical to improve and calibrate mathematical models of diazotrophic growth and the distribution of nitrogen fixation in the global ocean.
AB - Considering the reported significant diazotrophic activities in open-ocean regions where primary production is strongly limited by phosphate, we explored the ability of diazotrophs to use other sources of phosphorus to alleviate the phosphate depletion. We tested the actual efficiency of the open-ocean, N2-fixer Crocosphaera watsonii to grow on organic phosphorus as the sole P source, and observed how the P source affects the cellular C, N, and P composition. We obtained equivalent growth efficiencies on AMP and DL-α-glycerophosphate as compared with identical cultures grown on phosphate, and survival of the population on phytic acid. Our results show that Crocosphaera cannot use all phosphomonoesters with the same efficiency, but it can grow without phosphate, provided that usable DOP and sufficient light energy are available. Also, results point out that organic phosphorus uptake is not proportional to alkaline phosphatase activity, demonstrating that the latter is not a suitable proxy to estimate DOP-based growth yields of organisms, whether in culture experiments or in the natural environment. The growth parameters obtained, as a function of the P source, will be critical to improve and calibrate mathematical models of diazotrophic growth and the distribution of nitrogen fixation in the global ocean.
KW - Crocosphaera watsonii
KW - alkaline phosphatase
KW - dissolved organic phosphorus
KW - marine
KW - nitrogen fixation
KW - oligotrophic
KW - phosphonates
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U2 - 10.3389/fmicb.2022.848647
DO - 10.3389/fmicb.2022.848647
M3 - Article
AN - SCOPUS:85128403806
VL - 13
JO - Frontiers in Microbiology
JF - Frontiers in Microbiology
SN - 1664-302X
M1 - 848647
ER -