Co‐acquisition of mineral‐bound iron and phosphorus by natural Trichodesmium colonies

Shaked Y, de Beer D, Wang S, Zhang F, Visser A, Eichner M, Basu S (2023)

Publication Type: Journal article

Publication year: 2023

Journal

Limnology and Oceanography Association for the Sciences of Limnology and Oceanography (ASLO)

Book Volume: 68

Pages Range: 1064-1077

Issue: 5

DOI: 10.1002/lno.12329

Abstract

Low iron (Fe) and phosphorus (P) ocean regions are often home to the globally important N2-fixing cyanobacterium Trichodesmium spp., which are physiologically adapted to Fe/P co-limitation. Given Trichodesmium's eminent ability to capture particles and the common associations between Fe and P in sediments and aerosols, we hypothesized that mineral bio-dissolution by Trichodesmium spp. may enable them to co-acquire Fe and P. We present a new sensitive assay to determine P uptake from particles, utilizing 33P-labeled ferrihydrite. To validate the method, we examined single natural Trichodesmium thiebautii colonies in a high-resolution radiotracer ß-imager, identifying strong colony-mineral interactions, efficient removal of external 33P-labeled ferrihydrite, and elevated 33P uptake in the colony core. Next, we determined bulk P uptake rates, comparing natural Red Sea colonies and P-limited Trichodesmium erythraeum cultures. Uptake rates by natural and cultured Trichodesmium were similar to P release rates from the mineral, suggesting tight coupling between dissolution and uptake. Finally, synthesizing P-ferrihydrite labeled with either 33P or 55Fe, we probed for Fe/P co-extraction by common microbial mineral solubilization pathways. Dissolution rates of ferrihydrite were accelerated by exogenous superoxide and strong Fe-chelator and subsequently enhanced 33P release and uptake by Trichodesmium. Our method and findings can facilitate further Fe/P co-acquisition studies and highlight the importance of biological mechanisms and microenvironments in controlling bioavailability and nutrient fluxes from particles.

Authors with CRIS profile

Anna-Neva Visser

Involved external institutions

Academy of Sciences of the Czech Republic (ASCR) / Akademie věd České republiky (AVČR) CZ Czech Republic (CZ) Max-Planck-Institut für Marine Mikrobiologie (MPI-MM) DE Germany (DE) Hebrew University of Jerusalem IL Israel (IL)

How to cite

APA:

Shaked, Y., de Beer, D., Wang, S., Zhang, F., Visser, A., Eichner, M., & Basu, S. (2023). Co‐acquisition of mineral‐bound iron and phosphorus by natural <i>Trichodesmium</i> colonies. Limnology and Oceanography, 68, 1064-1077. https://doi.org/10.1002/lno.12329

MLA:

Shaked, Yeala, et al. "Co‐acquisition of mineral‐bound iron and phosphorus by natural <i>Trichodesmium</i> colonies." Limnology and Oceanography 68 (2023): 1064-1077.

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