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Calvanese M, D’Angelo C, Tutino ML, Lauro C. Whole-Cell Biosensor for Iron Monitoring as a Potential Tool for Safeguarding Biodiversity in Polar Marine Environments. Mar Drugs 2024; 22:299. [PMID: 39057408 PMCID: PMC11277574 DOI: 10.3390/md22070299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2024] [Revised: 06/05/2024] [Accepted: 06/24/2024] [Indexed: 07/28/2024] Open
Abstract
Iron is a key micronutrient essential for various essential biological processes. As a consequence, alteration in iron concentration in seawater can deeply influence marine biodiversity. In polar marine environments, where environmental conditions are characterized by low temperatures, the role of iron becomes particularly significant. While iron limitation can negatively influence primary production and nutrient cycling, excessive iron concentrations can lead to harmful algal blooms and oxygen depletion. Furthermore, the growth of certain phytoplankton species can be increased in high-iron-content environments, resulting in altered balance in the marine food web and reduced biodiversity. Although many chemical/physical methods are established for inorganic iron quantification, the determination of the bio-available iron in seawater samples is more suitably carried out using marine microorganisms as biosensors. Despite existing challenges, whole-cell biosensors offer other advantages, such as real-time detection, cost-effectiveness, and ease of manipulation, making them promising tools for monitoring environmental iron levels in polar marine ecosystems. In this review, we discuss fundamental biosensor designs and assemblies, arranging host features, transcription factors, reporter proteins, and detection methods. The progress in the genetic manipulation of iron-responsive regulatory and reporter modules is also addressed to the optimization of the biosensor performance, focusing on the improvement of sensitivity and specificity.
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Affiliation(s)
- Marzia Calvanese
- Department of Chemical Sciences, University of Naples “Federico II”, Complesso Universitario Monte S. Angelo, Via Cintia 4, 80126 Naples, Italy; (M.C.); (C.D.); (M.L.T.)
- Istituto Nazionale Biostrutture e Biosistemi (I.N.B.B), Viale Medaglie D’Oro 305, 00136 Roma, Italy
| | - Caterina D’Angelo
- Department of Chemical Sciences, University of Naples “Federico II”, Complesso Universitario Monte S. Angelo, Via Cintia 4, 80126 Naples, Italy; (M.C.); (C.D.); (M.L.T.)
| | - Maria Luisa Tutino
- Department of Chemical Sciences, University of Naples “Federico II”, Complesso Universitario Monte S. Angelo, Via Cintia 4, 80126 Naples, Italy; (M.C.); (C.D.); (M.L.T.)
- Istituto Nazionale Biostrutture e Biosistemi (I.N.B.B), Viale Medaglie D’Oro 305, 00136 Roma, Italy
| | - Concetta Lauro
- Department of Chemical Sciences, University of Naples “Federico II”, Complesso Universitario Monte S. Angelo, Via Cintia 4, 80126 Naples, Italy; (M.C.); (C.D.); (M.L.T.)
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2
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Przibilla A, Iwainski S, Zimmermann T, Pröfrock D. Impact of storage temperature and filtration method on dissolved trace metal concentrations in coastal water samples. WATER ENVIRONMENT RESEARCH : A RESEARCH PUBLICATION OF THE WATER ENVIRONMENT FEDERATION 2023; 95:e10922. [PMID: 37635266 DOI: 10.1002/wer.10922] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Revised: 08/08/2023] [Accepted: 08/22/2023] [Indexed: 08/29/2023]
Abstract
Trace elements play a major role in biogeochemical cycles and oceanographic processes. To determine trace element concentrations, the dissolved and particulate phase are usually separated by filtration. However, the frequently used membrane filtration as well as sample storage can bias the dissolved elemental concentrations by adsorption or desorption/contamination. We present a comparison of two filtration methods for coastal and estuarine water samples (pressure filtration with Nuclepore™ polycarbonate filters, vacuum filtration with DigiFILTER™s) applied to aliquots of a large-volume coastal water sample that were stored at -18°C or 4°C for up to nine weeks. The filtrates were analyzed by seaFAST-ICP-MS for dissolved Cd, Ce, Co, Cu, Dy, Er, Eu, Fe, Ho, La, Mn, Mo, Nd, Pb, Pr, Sm, Tb, U, V, W, Y, and Zn. The filtration blanks of DigiFILTER™s (0.0006 ± 0.0010 ng L-1 for Ho to 110 ± 180 ng L-1 for Zn) were sufficiently low for quantification of all analyzed elements with good repeatability, enabling a fast and reliable filtration of large sample sets of coastal water. However, the findings also highlight the need to measure procedural blanks including the filtration instead of only the instrument blanks to validate results. Measured concentrations of both filtration methods did not differ significantly for Cd, Cu, Mo, U, V, W, Zn but for other investigated elements, the ratio between both methods was up to 1.8 for Ce and 4.1 for Fe. Within nine weeks of storage, the elemental concentrations decreased significantly, resulting in losses of 20% Mn in frozen samples and 63% Pb, 64% Co and 93% Mn in cooled samples. PRACTITIONER POINTS: Two fast and cheap filtration methods for coastal water samples were compared. Dissolved concentrations of 22 elements were measured by seaFAST-ICP-MS. The filtration method is important in addition to filter pore size. Filtration blanks need to be reported to maintain comparability between methods. Cool and frozen storage of water samples biases the dissolved metal concentration.
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Affiliation(s)
- Anna Przibilla
- Institute of Coastal Environmental Chemistry/Department Inorganic Environmental Chemistry, Helmholtz-Zentrum Hereon, Geesthacht, Germany
- Department of Chemistry, Institute for Inorganic and Applied Chemistry, Universität Hamburg, Hamburg, Germany
| | - Susanna Iwainski
- Institute of Coastal Environmental Chemistry/Department Inorganic Environmental Chemistry, Helmholtz-Zentrum Hereon, Geesthacht, Germany
- Faculty of Chemistry and Biotechnology, Fachhochschule Aachen (Campus Jülich), Jülich, Germany
| | - Tristan Zimmermann
- Institute of Coastal Environmental Chemistry/Department Inorganic Environmental Chemistry, Helmholtz-Zentrum Hereon, Geesthacht, Germany
| | - Daniel Pröfrock
- Institute of Coastal Environmental Chemistry/Department Inorganic Environmental Chemistry, Helmholtz-Zentrum Hereon, Geesthacht, Germany
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3
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Fourquez M, Janssen DJ, Conway TM, Cabanes D, Ellwood MJ, Sieber M, Trimborn S, Hassler C. Chasing iron bioavailability in the Southern Ocean: Insights from Phaeocystis antarctica and iron speciation. SCIENCE ADVANCES 2023; 9:eadf9696. [PMID: 37379397 DOI: 10.1126/sciadv.adf9696] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Accepted: 05/24/2023] [Indexed: 06/30/2023]
Abstract
Dissolved iron (dFe) availability limits the uptake of atmospheric CO2 by the Southern Ocean (SO) biological pump. Hence, any change in bioavailable dFe in this region can directly influence climate. On the basis of Fe uptake experiments with Phaeocystis antarctica, we show that the range of dFe bioavailability in natural samples is wider (<1 to ~200% compared to free inorganic Fe') than previously thought, with higher bioavailability found near glacial sources. The degree of bioavailability varied regardless of in situ dFe concentration and depth, challenging the consensus that sole dFe concentrations can be used to predict Fe uptake in modeling studies. Further, our data suggest a disproportionately major role of biologically mediated ligands and encourage revisiting the role of humic substances in influencing marine Fe biogeochemical cycling in the SO. Last, we describe a linkage between in situ dFe bioavailability and isotopic signatures that, we anticipate, will stimulate future research.
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Affiliation(s)
- Marion Fourquez
- Aix Marseille Univ., Université de Toulon, CNRS, IRD, MIO UMR 110, Marseille 13288, France
- University of Geneva, Department F.-A. Forel for Environmental and Aquatic Sciences, Geneva 1211, Switzerland
| | - David J Janssen
- Department Surface Waters, Eawag-Swiss Federal Institute of Aquatic Science and Technology, Kastanienbaum, Switzerland
| | - Tim M Conway
- College of Marine Science, University of South Florida, St. Petersburg, FL 33701, USA
| | - Damien Cabanes
- University of Geneva, Department F.-A. Forel for Environmental and Aquatic Sciences, Geneva 1211, Switzerland
| | - Michael J Ellwood
- Research School of Earth Sciences, Australian National University, Canberra, ACT, Australia
- Australian Centre for Excellence in Antarctic Science, Research School of Earth Sciences, Australian National University, Canberra, ACT, Australia
| | - Matthias Sieber
- College of Marine Science, University of South Florida, St. Petersburg, FL 33701, USA
- Institute of Geochemistry and Petrology, ETH Zürich, Zürich, Switzerland
| | - Scarlett Trimborn
- Alfred Wegener Institute, Helmholtz Center for Polar and Marine Research, Bremerhaven 27570, Germany
| | - Christel Hassler
- University of Geneva, Department F.-A. Forel for Environmental and Aquatic Sciences, Geneva 1211, Switzerland
- Institute of Earth Sciences, University of Lausanne, Lausanne 1015, Switzerland
- School of Architecture, Civil, and Environmental Engineering, Ecole Polytechnique Fédérale de Lausanne, Sion 1951, Switzerland
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4
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Bridgestock L. Lead contamination of the deep Pacific Ocean via exchange with sinking particles. Proc Natl Acad Sci U S A 2023; 120:e2308014120. [PMID: 37319112 PMCID: PMC10293826 DOI: 10.1073/pnas.2308014120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/17/2023] Open
Affiliation(s)
- Luke Bridgestock
- School of Earth and Environmental Sciences, University of St Andrews, ScotlandKY16 9TS, United Kingdom
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5
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Guajardo-Leiva S, Mendez KN, Meneses C, Díez B, Castro-Nallar E. A First Insight into the Microbial and Viral Communities of Comau Fjord—A Unique Human-Impacted Ecosystem in Patagonia (42∘ S). Microorganisms 2023; 11:microorganisms11040904. [PMID: 37110327 PMCID: PMC10143455 DOI: 10.3390/microorganisms11040904] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 03/17/2023] [Accepted: 03/22/2023] [Indexed: 04/03/2023] Open
Abstract
While progress has been made in surveying the oceans to understand microbial and viral communities, the coastal ocean and, specifically, estuarine waters, where the effects of anthropogenic activity are greatest, remain partially understudied. The coastal waters of Northern Patagonia are of interest since this region experiences high-density salmon farming as well as other disturbances such as maritime transport of humans and cargo. Here, we hypothesized that viral and microbial communities from the Comau Fjord would be distinct from those collected in global surveys yet would have the distinctive features of microbes from coastal and temperate regions. We further hypothesized that microbial communities will be functionally enriched in antibiotic resistance genes (ARGs) in general and in those related to salmon farming in particular. Here, the analysis of metagenomes and viromes obtained for three surface water sites showed that the structure of the microbial communities was distinct in comparison to global surveys such as the Tara Ocean, though their composition converges with that of cosmopolitan marine microbes belonging to Proteobacteria, Bacteroidetes, and Actinobacteria. Similarly, viral communities were also divergent in structure and composition but matched known viral members from North America and the southern oceans. Microbial communities were functionally enriched in ARGs dominated by beta-lactams and tetracyclines, bacitracin, and the group macrolide–lincosamide–streptogramin (MLS) but were not different from other communities from the South Atlantic, South Pacific, and Southern Oceans. Similarly, viral communities were characterized by exhibiting protein clusters similar to those described globally (Tara Oceans Virome); however, Comau Fjord viromes displayed up to 50% uniqueness in their protein content. Altogether, our results indicate that microbial and viral communities from the Comau Fjord are a reservoir of untapped diversity and that, given the increasing anthropogenic impacts in the region, they warrant further study, specifically regarding resilience and resistance against antimicrobials and hydrocarbons.
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Affiliation(s)
- Sergio Guajardo-Leiva
- Departamento de Microbiología, Facultad de Ciencias de la Salud, Campus Talca, Universidad de Talca, Avda. Lircay s/n, Talca 3465548, Chile
- Centro de Ecología Integrativa, Campus Talca, Universidad de Talca, Avda. Lircay s/n, Talca 3465548, Chile
| | - Katterinne N. Mendez
- Center for Bioinformatics and Integrative Biology, Facultad de Ciencias de la Vida, Universidad Andrés Bello, Santiago 8370186, Chile
| | - Claudio Meneses
- Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago 8331150, Chile
- Departamento de Fruticultura y Enología, Facultad de Agronomía e Ingeniería Forestal, Pontificia Universidad Católica de Chile, Santiago 8331150, Chile
- ANID—Millennium Science Initiative Program—Millennium Nucleus for the Development of Super Adaptable Plants (MN-SAP), Santiago 8370186, Chile
| | - Beatriz Díez
- Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago 8331150, Chile
- Center for Climate and Resilience Research (CR)2, Santiago 8370449, Chile
- Millennium Institute Center for Genome Regulation (CGR), Santiago 7800003, Chile
| | - Eduardo Castro-Nallar
- Departamento de Microbiología, Facultad de Ciencias de la Salud, Campus Talca, Universidad de Talca, Avda. Lircay s/n, Talca 3465548, Chile
- Centro de Ecología Integrativa, Campus Talca, Universidad de Talca, Avda. Lircay s/n, Talca 3465548, Chile
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6
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Fitzsimmons JN, Conway TM. Novel Insights into Marine Iron Biogeochemistry from Iron Isotopes. ANNUAL REVIEW OF MARINE SCIENCE 2023; 15:383-406. [PMID: 36100217 DOI: 10.1146/annurev-marine-032822-103431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The micronutrient iron plays a major role in setting the magnitude and distribution of primary production across the global ocean. As such, an understanding of the sources, sinks, and internal cycling processes that drive the oceanic distribution of iron is key to unlocking iron's role in the global carbon cycle and climate, both today and in the geologic past. Iron isotopic analyses of seawater have emerged as a transformative tool for diagnosing iron sources to the ocean and tracing biogeochemical processes. In this review, we summarize the end-member isotope signatures of different iron source fluxes and highlight the novel insights into iron provenance gained using this tracer. We also review ways in which iron isotope fractionation might be used to understand internal oceanic cycling of iron, including speciation changes, biological uptake, and particle scavenging. We conclude with an overview of future research needed to expand the utilization of this cutting-edge tracer.
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Affiliation(s)
| | - Tim M Conway
- College of Marine Science, University of South Florida, St. Petersburg, Florida, USA;
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Sedwick PN, Sohst BM, O’Hara C, Stammerjohn SE, Loose B, Dinniman MS, Buck NJ, Resing JA, Ackley SF. Seasonal Dynamics of Dissolved Iron on the Antarctic Continental Shelf: Late-Fall Observations From the Terra Nova Bay and Ross Ice Shelf Polynyas. JOURNAL OF GEOPHYSICAL RESEARCH. OCEANS 2022; 127:e2022JC018999. [PMID: 36590600 PMCID: PMC9788290 DOI: 10.1029/2022jc018999] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 09/19/2022] [Accepted: 09/23/2022] [Indexed: 06/17/2023]
Abstract
Over the Ross Sea shelf, annual primary production is limited by dissolved iron (DFe) supply. Here, a major source of DFe to surface waters is thought to be vertical resupply from the benthos, which is assumed most prevalent during winter months when katabatic winds drive sea ice formation and convective overturn in coastal polynyas, although the impact of these processes on water-column DFe distributions has not been previously documented. We collected hydrographic data and water-column samples for trace metals analysis in the Terra Nova Bay and Ross Ice Shelf polynyas during April-May 2017 (late austral fall). In the Terra Nova Bay polynya, we observed intense katabatic wind events, and surface mixed layer depths varied from ∼250 to ∼600 m over lateral distances <10 km; there vertical mixing was just starting to excavate the dense, iron-rich Shelf Waters, and there was also evidence of DFe inputs at shallower depths in the water column. In the Ross Ice Shelf polynya, wind speeds were lower, mixed layers were <300 m deep, and DFe distributions were similar to previous, late-summer observations, with concentrations elevated near the seafloor. Corresponding measurements of dissolved manganese and zinc, and particulate iron, manganese, and aluminum, suggest that deep DFe maxima and some mid-depth DFe maxima primarily reflect sedimentary inputs, rather than remineralization. Our data and model simulations imply that vertical resupply of DFe in the Ross Sea occurs mainly during mid-late winter, and may be particularly sensitive to changes in the timing and extent of sea ice production.
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Affiliation(s)
- P. N. Sedwick
- Department of Ocean and Earth SciencesOld Dominion UniversityNorfolkVAUSA
| | - B. M. Sohst
- Department of Ocean and Earth SciencesOld Dominion UniversityNorfolkVAUSA
| | - C. O’Hara
- Department of Ocean and Earth SciencesOld Dominion UniversityNorfolkVAUSA
| | - S. E. Stammerjohn
- Institute of Arctic and Alpine ResearchUniversity of ColoradoBoulderCOUSA
| | - B. Loose
- Graduate School of OceanographyUniversity of Rhode IslandNarragansettRIUSA
| | - M. S. Dinniman
- Center for Coastal Physical OceanographyOld Dominion UniversityNorfolkVAUSA
| | - N. J. Buck
- Cooperative Institute for Climate, Oceans, and Ecosystem StudiesUniversity of WashingtonSeattleWAUSA
- NOAA Pacific Marine Environmental LaboratorySeattleWAUSA
| | - J. A. Resing
- Cooperative Institute for Climate, Oceans, and Ecosystem StudiesUniversity of WashingtonSeattleWAUSA
- NOAA Pacific Marine Environmental LaboratorySeattleWAUSA
| | - S. F. Ackley
- Center for Advanced Measurements in Extreme EnvironmentsUniversity of Texas at San AntonioSan AntonioTXUSA
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8
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Wahyudi AJ, Taufiqurrahman E. Variability of trace metals in coastal and estuary: Distribution, profile, and drivers. MARINE POLLUTION BULLETIN 2022; 174:113173. [PMID: 34875477 DOI: 10.1016/j.marpolbul.2021.113173] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 11/15/2021] [Accepted: 11/16/2021] [Indexed: 06/13/2023]
Abstract
Ongoing global changes such as increasing sea-surface temperatures, decreasing acidity levels, and expanding oxygen-minimum zone may impact on the biogeochemical cycles of trace metals in ocean systems. Each trace metal has unique characteristics and a distinctive distribution pattern controlled by chemical, biological, and physical processes that occur in ocean systems. The correlations of variability drivers in trace metals are interesting topics for investigation. Following up on ocean research in the coastal and estuary area, we specifically review the distribution of trace metals in seawater and suspended and surface sediment. The marginal seas usually feature significant terrestrial inputs accompanied by several active water-mass currents. The purpose of this review is to provide an overview of variability related to trace-metal distribution in coastal and estuary systems and to specifically describe the distribution, profile and drivers that affect trace metals variability.
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Affiliation(s)
- A'an Johan Wahyudi
- Research Center for Oceanography, National Research and Innovation Agency (BRIN), Jl. Pasir Putih 1, Ancol Timur, Jakarta, Indonesia
| | - Edwards Taufiqurrahman
- Research Center for Oceanography, National Research and Innovation Agency (BRIN), Jl. Pasir Putih 1, Ancol Timur, Jakarta, Indonesia
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9
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Feng S, Wu J, Chen G. Determination of Picomolar Titanium in Seawater by Isotope Dilution Multicollector Inductively Coupled Plasma Mass Spectrometry after Mg(OH) 2 Coprecipitation. Anal Chem 2021; 93:13118-13125. [PMID: 34546057 DOI: 10.1021/acs.analchem.0c04381] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A new isotope dilution inductively coupled plasma mass spectrometry (ICPMS) method is developed to determine picomolar concentrations of titanium (Ti) in seawater. The method applies Mg(OH)2 coprecipitation to concentrate Ti from seawater, and uses a new 49Ti-47Ti isotope dilution to eliminate the need for separating Ti from seawater Ca, resulting in an isobaric interference-free analysis by high-resolution multicollector ICPMS. The method uses a 1.8 mL seawater sample with a detection limit of 1.6 pmol L-1 that is determined mainly by Ti contamination during sample preparation rather than by ICPMS sensitivity, instrumental Ti background, or isobaric interferences. An oceanographically consistent vertical profile of dissolved Ti in the Sargasso Sea near Bermuda is measured with this method.
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Affiliation(s)
- Sichao Feng
- Rosenstiel School of Marine and Atmospheric Science, University of Miami, Coral Gables, 33149 Florida, United States
| | - Jingfeng Wu
- Rosenstiel School of Marine and Atmospheric Science, University of Miami, Coral Gables, 33149 Florida, United States
| | - Gedun Chen
- Rosenstiel School of Marine and Atmospheric Science, University of Miami, Coral Gables, 33149 Florida, United States
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10
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Shaked Y, Twining BS, Tagliabue A, Maldonado MT. Probing the Bioavailability of Dissolved Iron to Marine Eukaryotic Phytoplankton Using In Situ Single Cell Iron Quotas. GLOBAL BIOGEOCHEMICAL CYCLES 2021; 35:e2021GB006979. [PMID: 35865367 PMCID: PMC9286392 DOI: 10.1029/2021gb006979] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 06/09/2021] [Accepted: 06/29/2021] [Indexed: 05/08/2023]
Abstract
We present a new approach for quantifying the bioavailability of dissolved iron (dFe) to oceanic phytoplankton. Bioavailability is defined using an uptake rate constant (kin-app) computed by combining data on: (a) Fe content of individual in situ phytoplankton cells; (b) concurrently determined seawater dFe concentrations; and (c) growth rates estimated from the PISCES model. We examined 930 phytoplankton cells, collected between 2002 and 2016 from 45 surface stations during 11 research cruises. This approach is only valid for cells that have upregulated their high-affinity Fe uptake system, so data were screened, yielding 560 single cell k in-app values from 31 low-Fe stations. We normalized k in-app to cell surface area (S.A.) to account for cell-size differences. The resulting bioavailability proxy (k in-app/S.A.) varies among cells, but all values are within bioavailability limits predicted from defined Fe complexes. In situ dFe bioavailability is higher than model Fe-siderophore complexes and often approaches that of highly available inorganic Fe'. Station averaged k in-app/S.A. are also variable but show no systematic changes across location, temperature, dFe, and phytoplankton taxa. Given the relative consistency of k in-app/S.A. among stations (ca. five-fold variation), we computed a grand-averaged dFe availability, which upon normalization to cell carbon (C) yields k in-app/C of 42,200 ± 11,000 L mol C-1 d-1. We utilize k in-app/C to calculate dFe uptake rates and residence times in low Fe oceanic regions. Finally, we demonstrate the applicability of k in-app/C for constraining Fe uptake rates in earth system models, such as those predicting climate mediated changes in net primary production in the Fe-limited Equatorial Pacific.
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Affiliation(s)
- Yeala Shaked
- Freddy and Nadine Herrmann Institute of Earth SciencesHebrew UniversityJerusalemIsrael
- Interuniversity Institute for Marine SciencesEilatIsrael
| | | | | | - Maria T. Maldonado
- Department of Earth, Ocean and Atmospheric SciencesUniversity of British ColumbiaVancouverCanada
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11
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Iron transport in cyanobacteria - from molecules to communities. Trends Microbiol 2021; 30:229-240. [PMID: 34175176 DOI: 10.1016/j.tim.2021.06.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Revised: 06/01/2021] [Accepted: 06/01/2021] [Indexed: 11/22/2022]
Abstract
Iron is an essential micronutrient for the ecologically important photoautotrophic cyanobacteria which are found across diverse aquatic environments. Low concentrations and poor bioavailability of certain iron species exert a strong control on cyanobacterial growth, affecting ecosystem structure and biogeochemical cycling. Here, we review the iron-acquisition pathways cyanobacteria utilize for overcoming these challenges. As the molecular details of cyanobacterial iron transport are being uncovered, an overall scheme of how cyanobacteria handle and exploit this scarce and redox-active micronutrient is emerging. Importantly, the range of biological solutions used by cyanobacteria to increase iron fluxes goes beyond transport and includes behavioral traits of colonial cyanobacteria and intricate cyanobacteria-bacteria interactions.
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12
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Hunnestad AV, Vogel AIM, Armstrong E, Digernes MG, Ardelan MV, Hohmann-Marriott MF. From the Ocean to the Lab-Assessing Iron Limitation in Cyanobacteria: An Interface Paper. Microorganisms 2020; 8:E1889. [PMID: 33260337 PMCID: PMC7760322 DOI: 10.3390/microorganisms8121889] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 11/25/2020] [Accepted: 11/26/2020] [Indexed: 12/22/2022] Open
Abstract
Iron is an essential, yet scarce, nutrient in marine environments. Phytoplankton, and especially cyanobacteria, have developed a wide range of mechanisms to acquire iron and maintain their iron-rich photosynthetic machinery. Iron limitation studies often utilize either oceanographic methods to understand large scale processes, or laboratory-based, molecular experiments to identify underlying molecular mechanisms on a cellular level. Here, we aim to highlight the benefits of both approaches to encourage interdisciplinary understanding of the effects of iron limitation on cyanobacteria with a focus on avoiding pitfalls in the initial phases of collaboration. In particular, we discuss the use of trace metal clean methods in combination with sterile techniques, and the challenges faced when a new collaboration is set up to combine interdisciplinary techniques. Methods necessary for producing reliable data, such as High Resolution Inductively Coupled Plasma Mass Spectrometry (HR-ICP-MS), Flow Injection Analysis Chemiluminescence (FIA-CL), and 77K fluorescence emission spectroscopy are discussed and evaluated and a technical manual, including the preparation of the artificial seawater medium Aquil, cleaning procedures, and a sampling scheme for an iron limitation experiment is included. This paper provides a reference point for researchers to implement different techniques into interdisciplinary iron studies that span cyanobacteria physiology, molecular biology, and biogeochemistry.
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Affiliation(s)
- Annie Vera Hunnestad
- Department of Chemistry, Norwegian University of Science and Technology (NTNU), 7491 Trondheim, Norway; (A.V.H.); (M.G.D.)
| | - Anne Ilse Maria Vogel
- PhotoSynLab, Department of Biotechnology and Food Science, Norwegian University of Science and Technology (NTNU), 7491 Trondheim, Norway; (A.I.M.V.); (M.F.H.-M.)
| | - Evelyn Armstrong
- NIWA/University of Otago Research Centre for Oceanography, Department of Chemistry, University of Otago, 9054 Dunedin, New Zealand;
| | - Maria Guadalupe Digernes
- Department of Chemistry, Norwegian University of Science and Technology (NTNU), 7491 Trondheim, Norway; (A.V.H.); (M.G.D.)
| | - Murat Van Ardelan
- Department of Chemistry, Norwegian University of Science and Technology (NTNU), 7491 Trondheim, Norway; (A.V.H.); (M.G.D.)
| | - Martin Frank Hohmann-Marriott
- PhotoSynLab, Department of Biotechnology and Food Science, Norwegian University of Science and Technology (NTNU), 7491 Trondheim, Norway; (A.I.M.V.); (M.F.H.-M.)
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13
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Sutak R, Camadro JM, Lesuisse E. Iron Uptake Mechanisms in Marine Phytoplankton. Front Microbiol 2020; 11:566691. [PMID: 33250865 PMCID: PMC7676907 DOI: 10.3389/fmicb.2020.566691] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Accepted: 10/19/2020] [Indexed: 12/20/2022] Open
Abstract
Oceanic phytoplankton species have highly efficient mechanisms of iron acquisition, as they can take up iron from environments in which it is present at subnanomolar concentrations. In eukaryotes, three main models were proposed for iron transport into the cells by first studying the kinetics of iron uptake in different algal species and then, more recently, by using modern biological techniques on the model diatom Phaeodactylum tricornutum. In the first model, the rate of uptake is dependent on the concentration of unchelated Fe species, and is thus limited thermodynamically. Iron is transported by endocytosis after carbonate-dependent binding of Fe(III)' (inorganic soluble ferric species) to phytotransferrin at the cell surface. In this strategy the cells are able to take up iron from very low iron concentration. In an alternative model, kinetically limited for iron acquisition, the extracellular reduction of all iron species (including Fe') is a prerequisite for iron acquisition. This strategy allows the cells to take up iron from a great variety of ferric species. In a third model, hydroxamate siderophores can be transported by endocytosis (dependent on ISIP1) after binding to the FBP1 protein, and iron is released from the siderophores by FRE2-dependent reduction. In prokaryotes, one mechanism of iron uptake is based on the use of siderophores excreted by the cells. Iron-loaded siderophores are transported across the cell outer membrane via a TonB-dependent transporter (TBDT), and are then transported into the cells by an ABC transporter. Open ocean cyanobacteria do not excrete siderophores but can probably use siderophores produced by other organisms. In an alternative model, inorganic ferric species are transported through the outer membrane by TBDT or by porins, and are taken up by the ABC transporter system FutABC. Alternatively, ferric iron of the periplasmic space can be reduced by the alternative respiratory terminal oxidase (ARTO) and the ferrous ions can be transported by divalent metal transporters (FeoB or ZIP). After reoxidation, iron can be taken up by the high-affinity permease Ftr1.
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Affiliation(s)
- Robert Sutak
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Vestec, Czechia
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Shaked Y, Buck KN, Mellett T, Maldonado MT. Insights into the bioavailability of oceanic dissolved Fe from phytoplankton uptake kinetics. THE ISME JOURNAL 2020; 14:1182-1193. [PMID: 32024947 PMCID: PMC7174416 DOI: 10.1038/s41396-020-0597-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Revised: 01/12/2020] [Accepted: 01/21/2020] [Indexed: 12/05/2022]
Abstract
Phytoplankton growth in large parts of the world ocean is limited by low availability of dissolved iron (dFe), restricting oceanic uptake of atmospheric CO2. The bioavailability of dFe in seawater is however difficult to appraise since it is bound by a variety of poorly characterized organic ligands. Here, we propose a new approach for evaluating seawater dFe bioavailability based on its uptake rate constant by Fe-limited cultured phytoplankton. We utilized seven phytoplankton species of diverse classes, sizes, and provenances to probe for dFe bioavailability in 12 seawater samples from several ocean basins and depths. All tested phytoplankton acquired organically bound Fe in any given sample at similar rates (after normalizing to cellular surface area), confirming that multiple, Fe-limited phytoplankton species can be used to probe dFe bioavailability in seawater. These phytoplankton-based uptake rate constants allowed us to compare water types, and obtain a grand average estimate of seawater dFe bioavailability. Among water types, dFe bioavailability varied by approximately four-fold, and did not clearly correlate with Fe concentrations or any of the measured Fe speciation parameters. Compared with well-studied Fe complexes, seawater dFe is more available than model siderophore Fe, but less available than inorganic Fe. Exposure of seawater to sunlight, however, significantly enhanced dFe bioavailability. The rate constants established in this work, not only facilitate comparison between water types, but also allow calculation of Fe uptake rates by phytoplankton in the ocean based on measured dFe concentrations. The approach established and verified in this study, opens a new way for determining dFe bioavailability in samples across the ocean, and enables modeling of in situ Fe uptake rates by phytoplankton using dFe concentrations from GEOTRACES datasets.
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Affiliation(s)
- Yeala Shaked
- The Fredy and Nadine Herrmann Institute of Earth Sciences, Hebrew University of Jerusalem, Jerusalem, Israel.
- Interuniversity Institute for Marine Sciences, Eilat, Israel.
| | - Kristen N Buck
- College of Marine Science, University of South Florida, Tampa, FL, USA
| | - Travis Mellett
- College of Marine Science, University of South Florida, Tampa, FL, USA
| | - Maria T Maldonado
- Earth, Ocean and Atmospheric Sciences Department, University of British Columbia, Vancouver, BC, Canada
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Gaonkar CV, Kumar A, Matta VM, Kurian S. Assessment of crustal element and trace metal concentrations in atmospheric particulate matter over a coastal city in the Eastern Arabian Sea. JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION (1995) 2020; 70:78-92. [PMID: 31613714 DOI: 10.1080/10962247.2019.1680458] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Revised: 09/30/2019] [Accepted: 10/09/2019] [Indexed: 06/10/2023]
Abstract
Major/crustal elements (Al, Ca, Mg, K, and Fe) and trace metals (Mn, Cr, Cu, Pb, Zn, and Ni) in atmospheric particulate matter at three sites in Goa (a coastal city in the Eastern Arabian Sea) were assessed during winter (December) and summer (March-May) months of 2015. A significant spatial and temporal variability was observed in PM10 mass concentration, crustal element, and trace metal composition at the sampling area (pristine, urban, and industrial locations). Using a diagnostic crustal element ratio (Fe/Al, Ca/Al, and Mg/Al), mineral dust components were characterized and found to show large spatial and temporal variability. The concentration levels of trace metals were further assessed for enrichment factor (EF) analysis, wherein reported elements were classified into two major groups. The first group consists of Cr, Cu, and Pb with 10< EF < 100 compared to continental crustal values (w.r.t. Al), suggesting a dominant contribution from anthropogenic sources with minor contribution from natural sources; the second group consists of Zn and Ni showing very high EF (>100)-these are solely derived from anthropogenic sources. Source identification for trace metals was further assessed based on principle component analysis (PCA). PCA highlights that the major contribution of trace metals is from anthropogenic emissions at all three locations. However, contributions from mineral dust were observed at pristine and urban locations during winter months. The reported data of trace metal concentrations in aerosols give baseline information on the atmospheric supply of micronutrients to the Arabian Sea, which has implications for the various surface ocean biogeochemical processes.Implications: This paper reports on crustal and trace metal composition and concentration level in atmospheric aerosols over a coastal city located on the Eastern Arabian Sea. This study highlights the role of various factors (meteorology and emission sources) controlling the abundance of metals over a coastal site. The contribution from various sources (anthropogenic vis-à-vis natural) has also been identified using enrichment factor analysis as well as principle component analysis. This study has implications for the supply of micronutrients to the coastal Arabian Sea, which can significantly impact various surface ocean biogeochemical processes.
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Affiliation(s)
- Cynthia V Gaonkar
- The School of Earth, Ocean and Atmospheric Sciences, Goa University, Taleigao, India
| | - Ashwini Kumar
- CSIR-National Institute of Oceanography, Doan Paula, India
| | - Vishnu Murty Matta
- The School of Earth, Ocean and Atmospheric Sciences, Goa University, Taleigao, India
| | - Siby Kurian
- CSIR-National Institute of Oceanography, Doan Paula, India
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