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The role of trace metals in controlling structure and function of microbial communities in contemporary oceans
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Dust as a source of Phosphorus for natural and cultured Trichodesmium P-C3-04-S Siyuan Wang* , 1. Interuniversity Institute for Marine Science - Eilat, POB 469, Eilat 88103, Israel
2. The Freddy and Nadine Herman Institute of Earth Sciences, Edmond J Safra Campus, Givat Ram, Hebrew University of Jerusalem, Jerusalem, Israel
Subhajit Basu, 1. Interuniversity Institute for Marine Science - Eilat, POB 469, Eilat 88103, Israel
2. The Freddy and Nadine Herman Institute of Earth Sciences, Edmond J Safra Campus, Givat Ram, Hebrew University of Jerusalem, Jerusalem, Israel
Yeala Shaked, 1. Interuniversity Institute for Marine Science - Eilat, POB 469, Eilat 88103, Israel
2. The Freddy and Nadine Herman Institute of Earth Sciences, Edmond J Safra Campus, Givat Ram, Hebrew University of Jerusalem, Jerusalem, Israel
Presenter Email: 834711819@qq.com |
Trichodesmium, a globally important N2-fixing phytoplankton, establishes large blooms in subtropical/tropical ocean waters and sustains other marine microbes by releasing fixed nitrogen and carbon. Phosphorus (P), an essential plant nutrient, is found in short supply in many oceanic ecosystems. Large fluxes of aeolian dust provide the ocean surface with large quantities of P, but the low solubility of dust-P, turns aeolian dust to a rather poor source of bioavailable P.
Our study explores the ability of Trichodesmium colonies from the Gulf of Aqaba, Red Sea, to utilize dust as a source of P. In response to P-stress, many microorganisms activate the extracellular enzyme Alkaline Phosphatase (AP), which is commonly used as a reporter of the cell's P-nutrition. In this study, we measured AP Activity (APA) of natural and cultured Trichodesmium prior to and following dust addition.
P-limited Trichodesmium IMS101 cultures expressed high APA, which dropped shortly (5hrs) after phosphate addition, indicating that APA is a good probe for the cell's P-stress. Natural colonies from the Gulf of Aqaba were found to be P-limited based on high APA detected in single fresh colony. Desert dust added at a range of concentrations to P-limited cultures or individual natural colony resulted in a drop of APA, suggesting that dust supplied enough P to meet the cell's P-requirements.
These data are part of an extensive research examining the adaptations enabling natural Trichodesmium colonies to utilize dust as a source of P including sensing, selection, collection and processing of dust and P-rich particles. Our preliminary findings of efficient utilization of dust-P by Trichodesmium may have significant implications on the marine biogeochemical cycles of P, N, and C.
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