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Elbagoury NM, Abdel-Aleem AF, Sharaf-Eldin WE, Ashaat EA, Esswai ML. A Novel Truncating Mutation in PAX1 Gene Causes Otofaciocervical Syndrome Without Immunodeficiency. J Mol Neurosci 2023; 73:976-982. [PMID: 37924468 PMCID: PMC10754723 DOI: 10.1007/s12031-023-02170-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2023] [Accepted: 10/24/2023] [Indexed: 11/06/2023]
Abstract
Otofaciocervical syndrome (OTFCS) is a rare genetic disorder of both autosomal recessive and autosomal dominant patterns of inheritance. It is caused by biallelic or monoallelic mutations in PAX1 or EYA1 genes, respectively. Here, we report an OTFCS2 female patient of 1st consanguineous healthy parents. She manifested facial dysmorphism, hearing loss, intellectual disability (ID), and delayed language development (DLD) as the main clinical phenotype. The novel homozygous variant c.1212dup (p.Gly405Argfs*51) in the PAX1 gene was identified by whole exome sequencing (WES), and family segregation confirmed the heterozygous status of the mutation in the parents using the Sanger sequencing. The study recorded a novel PAX1 variant representing the sixth report of OTFCS2 worldwide and the first Egyptian study expanding the geographic area where the disorder was confined.
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Affiliation(s)
- Nagham M Elbagoury
- Medical Molecular Genetics Department, Human Genetics and Genome Research Institute, National Research Centre, Cairo, Egypt
| | - Asmaa F Abdel-Aleem
- Medical Molecular Genetics Department, Human Genetics and Genome Research Institute, National Research Centre, Cairo, Egypt.
| | - Wessam E Sharaf-Eldin
- Medical Molecular Genetics Department, Human Genetics and Genome Research Institute, National Research Centre, Cairo, Egypt
| | - Engy A Ashaat
- Clinical Genetics Department, Human Genetics and Genome Research Institute, National Research Centre, Cairo, Egypt
| | - Mona L Esswai
- Medical Molecular Genetics Department, Human Genetics and Genome Research Institute, National Research Centre, Cairo, Egypt
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2
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Jiang HB, Hutchins DA, Ma W, Zhang RF, Wells M, Jiao N, Wang Y, Chai F. Natural ocean iron fertilization and climate variability over geological periods. GLOBAL CHANGE BIOLOGY 2023; 29:6856-6866. [PMID: 37855153 DOI: 10.1111/gcb.16990] [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: 07/18/2023] [Revised: 09/20/2023] [Accepted: 09/27/2023] [Indexed: 10/20/2023]
Abstract
Marine primary producers are largely dependent on and shape the Earth's climate, although their relationship with climate varies over space and time. The growth of phytoplankton and associated marine primary productivity in most of the modern global ocean is limited by the supply of nutrients, including the micronutrient iron. The addition of iron via episodic and frequent events drives the biological carbon pump and promotes the sequestration of atmospheric carbon dioxide (CO2 ) into the ocean. However, the dependence between iron and marine primary producers adaptively changes over different geological periods due to the variation in global climate and environment. In this review, we examined the role and importance of iron in modulating marine primary production during some specific geological periods, that is, the Great Oxidation Event (GOE) during the Huronian glaciation, the Snowball Earth Event during the Cryogenian, the glacial-interglacial cycles during the Pleistocene, and the period from the last glacial maximum to the late Holocene. Only the change trend of iron bioavailability and climate in the glacial-interglacial cycles is consistent with the Iron Hypothesis. During the GOE and the Snowball Earth periods, although the bioavailability of iron in the ocean and the climate changed dramatically, the changing trend of many factors contradicted the Iron Hypothesis. By detangling the relationship among marine primary productivity, iron availability and oceanic environments in different geological periods, this review can offer some new insights for evaluating the impact of ocean iron fertilization on removing CO2 from the atmosphere and regulating the climate.
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Affiliation(s)
- Hai-Bo Jiang
- Key Laboratory of Marine Biotechnology of Zhejiang Province, School of Marine Sciences, Ningbo University, Ningbo, Zhejiang, China
- State Key Laboratory of Satellite Ocean Environment Dynamics, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, Zhejiang, China
- Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai, Guangdong, China
| | - David A Hutchins
- Department of Biological Sciences, University of Southern California, Los Angeles, California, USA
| | - Wentao Ma
- State Key Laboratory of Satellite Ocean Environment Dynamics, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, Zhejiang, China
| | - Rui-Feng Zhang
- School of Oceanography, Shanghai Jiaotong University, Shanghai, Shanghai, China
| | - Mark Wells
- State Key Laboratory of Satellite Ocean Environment Dynamics, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, Zhejiang, China
- School of Marine Sciences, University of Maine, Orono, Maine, USA
| | - Nianzhi Jiao
- State Key Laboratory of Marine Environmental Sciences, Xiamen University, Xiamen, Fujian, China
| | - Yuntao Wang
- State Key Laboratory of Satellite Ocean Environment Dynamics, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, Zhejiang, China
| | - Fei Chai
- State Key Laboratory of Satellite Ocean Environment Dynamics, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, Zhejiang, China
- State Key Laboratory of Marine Environmental Sciences, Xiamen University, Xiamen, Fujian, China
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3
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Balaguer J, Koch F, Flintrop CM, Völkner C, Iversen MH, Trimborn S. Iron and manganese availability drives primary production and carbon export in the Weddell Sea. Curr Biol 2023; 33:4405-4414.e4. [PMID: 37769661 DOI: 10.1016/j.cub.2023.08.086] [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: 01/30/2023] [Revised: 07/17/2023] [Accepted: 08/30/2023] [Indexed: 10/03/2023]
Abstract
Next to iron (Fe), recent phytoplankton-enrichment experiments identified manganese (Mn) to (co-)limit Southern Ocean phytoplankton biomass and species composition. Since taxonomic diversity affects aggregation time and sinking rate, the efficiency of the biological carbon pump is directly affected by community structure. However, the impact of FeMn co-limitation on Antarctic primary production, community composition, and the subsequent export of carbon to depth requires more investigation. In situ samplings of 6 stations in the understudied southern Weddell Sea revealed that surface Fe and Mn concentrations, primary production, and carbon export rates were all low, suggesting a FeMn co-limited phytoplankton community. An Fe and Mn addition experiment examined how changes in the species composition drive the aggregation capability of a natural phytoplankton community. Primary production rates were highest when Fe and Mn were added together, due to an increased abundance of the colonial prymnesiophyte Phaeocystis antarctica. Although the community remained diatom dominated, the increase in Phaeocystis abundance led to highly carbon-enriched aggregates and a 4-fold increase in the carbon export potential compared to the control, whereas it only doubled in the Fe treatment. Based on the outcome of the FeMn-enrichment experiment, this region may suffer from FeMn co-limitation. As the Weddell Sea represents one of the most productive Antarctic marginal ice zones, our findings highlight that in response to greater Fe and Mn supply, changes in plankton community composition and primary production can have a disproportionally larger effect on the carbon export potential.
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Affiliation(s)
- Jenna Balaguer
- Marine Botany, University of Bremen, Bremen 28359, Germany; Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Bremerhaven 25570, Germany.
| | - Florian Koch
- Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Bremerhaven 25570, Germany
| | - Clara M Flintrop
- Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Bremerhaven 25570, Germany; The Fredy & Nadine Herrmann Institute of Earth Sciences, Hebrew University of Jerusalem, Jerusalem 91904, Israel; Interuniversity Institute for Marine Sciences, Eilat 88103, Israel
| | - Christian Völkner
- Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Bremerhaven 25570, Germany
| | - Morten H Iversen
- Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Bremerhaven 25570, Germany; MARUM Center for Marine Environmental Sciences, University of Bremen, Bremen 28359, Germany
| | - Scarlett Trimborn
- Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Bremerhaven 25570, Germany
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4
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Sharpe G, Zhao L, Meyer MG, Gong W, Burns SM, Tagliabue A, Buck KN, Santoro AE, Graff JR, Marchetti A, Gifford S. Synechococcus nitrogen gene loss in iron-limited ocean regions. ISME COMMUNICATIONS 2023; 3:107. [PMID: 37783796 PMCID: PMC10545762 DOI: 10.1038/s43705-023-00314-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Revised: 09/15/2023] [Accepted: 09/21/2023] [Indexed: 10/04/2023]
Abstract
Synechococcus are the most abundant cyanobacteria in high latitude regions and are responsible for an estimated 17% of annual marine net primary productivity. Despite their biogeochemical importance, Synechococcus populations have been unevenly sampled across the ocean, with most studies focused on low-latitude strains. In particular, the near absence of Synechococcus genomes from high-latitude, High Nutrient Low Chlorophyll (HNLC) regions leaves a gap in our knowledge of picocyanobacterial adaptations to iron limitation and their influence on carbon, nitrogen, and iron cycles. We examined Synechococcus populations from the subarctic North Pacific, a well-characterized HNLC region, with quantitative metagenomics. Assembly with short and long reads produced two near complete Synechococcus metagenome-assembled genomes (MAGs). Quantitative metagenome-derived abundances of these populations matched well with flow cytometry counts, and the Synechococcus MAGs were estimated to comprise >99% of the Synechococcus at Station P. Whereas the Station P Synechococcus MAGs contained multiple genes for adaptation to iron limitation, both genomes lacked genes for uptake and assimilation of nitrate and nitrite, suggesting a dependence on ammonium, urea, and other forms of recycled nitrogen leading to reduced iron requirements. A global analysis of Synechococcus nitrate reductase abundance in the TARA Oceans dataset found nitrate assimilation genes are also lower in other HNLC regions. We propose that nitrate and nitrite assimilation gene loss in Synechococcus may represent an adaptation to severe iron limitation in high-latitude regions where ammonium availability is higher. Our findings have implications for models that quantify the contribution of cyanobacteria to primary production and subsequent carbon export.
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Affiliation(s)
- Garrett Sharpe
- Environment Ecology and Energy Program, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Liang Zhao
- Earth, Marine and Environmental Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Meredith G Meyer
- Earth, Marine and Environmental Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Weida Gong
- Earth, Marine and Environmental Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Shannon M Burns
- College of Marine Science, University of South Florida, St. Petersburg, FL, USA
| | | | - Kristen N Buck
- College of Marine Science, University of South Florida, St. Petersburg, FL, USA
- College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, Corvallis, OR, USA
| | - Alyson E Santoro
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, CA, USA
| | - Jason R Graff
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR, USA
| | - Adrian Marchetti
- Earth, Marine and Environmental Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Scott Gifford
- Earth, Marine and Environmental Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
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5
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Bonnet S, Guieu C, Taillandier V, Boulart C, Bouruet-Aubertot P, Gazeau F, Scalabrin C, Bressac M, Knapp AN, Cuypers Y, González-Santana D, Forrer HJ, Grisoni JM, Grosso O, Habasque J, Jardin-Camps M, Leblond N, Le Moigne FAC, Lebourges-Dhaussy A, Lory C, Nunige S, Pulido-Villena E, Rizzo AL, Sarthou G, Tilliette C. Natural iron fertilization by shallow hydrothermal sources fuels diazotroph blooms in the ocean. Science 2023; 380:812-817. [PMID: 37228198 DOI: 10.1126/science.abq4654] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Accepted: 04/21/2023] [Indexed: 05/27/2023]
Abstract
Iron is an essential nutrient that regulates productivity in ~30% of the ocean. Compared with deep (>2000 meter) hydrothermal activity at mid-ocean ridges that provide iron to the ocean's interior, shallow (<500 meter) hydrothermal fluids are likely to influence the surface's ecosystem. However, their effect is unknown. In this work, we show that fluids emitted along the Tonga volcanic arc (South Pacific) have a substantial impact on iron concentrations in the photic layer through vertical diffusion. This enrichment stimulates biological activity, resulting in an extensive patch of chlorophyll (360,000 square kilometers). Diazotroph activity is two to eight times higher and carbon export fluxes are two to three times higher in iron-enriched waters than in adjacent unfertilized waters. Such findings reveal a previously undescribed mechanism of natural iron fertilization in the ocean that fuels regional hotspot sinks for atmospheric CO2.
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Affiliation(s)
- Sophie Bonnet
- Aix Marseille University, Université de Toulon, CNRS, IRD, MIO Marseille, France
| | - Cécile Guieu
- Laboratoire d'Océanographie de Villefranche (LOV), Institut de la Mer de Villefranche, CNRS, Sorbonne Université, 06230 Villefranche-sur-Mer, France
| | - Vincent Taillandier
- Laboratoire d'Océanographie de Villefranche (LOV), Institut de la Mer de Villefranche, CNRS, Sorbonne Université, 06230 Villefranche-sur-Mer, France
| | - Cédric Boulart
- Adaptation et Diversité en Milieu Marin, UMR 7144 AD2M CNRS-Sorbonne Université, Station Biologique de Roscoff, 29680 Roscoff, France
| | - Pascale Bouruet-Aubertot
- Laboratoire d'Océanographie et du Climat: Expérimentation et Approches Numériques (LOCEAN-IPSL), Sorbonne University, CNRS-IRD-MNHN, 75005 Paris, France
| | - Frédéric Gazeau
- Laboratoire d'Océanographie de Villefranche (LOV), Institut de la Mer de Villefranche, CNRS, Sorbonne Université, 06230 Villefranche-sur-Mer, France
| | - Carla Scalabrin
- Ifremer, Univ Brest, CNRS, UMR 6538 Geo-Ocean, F-29280 Plouzané, France
| | - Matthieu Bressac
- Laboratoire d'Océanographie de Villefranche (LOV), Institut de la Mer de Villefranche, CNRS, Sorbonne Université, 06230 Villefranche-sur-Mer, France
| | - Angela N Knapp
- Department of Earth, Ocean, and Atmospheric Sciences, Florida State University, Tallahassee, FL 32306, USA
| | - Yannis Cuypers
- Laboratoire d'Océanographie et du Climat: Expérimentation et Approches Numériques (LOCEAN-IPSL), Sorbonne University, CNRS-IRD-MNHN, 75005 Paris, France
| | - David González-Santana
- CNRS, Univ Brest, IRD, Ifremer, UMR 6539, LEMAR, Plouzané, France
- Instituto de Oceanografía y Cambio Global (IOCAG), Universidad de Las Palmas de Gran Canaria, 35017 Las Palmas, Spain
| | - Heather J Forrer
- Department of Earth, Ocean, and Atmospheric Sciences, Florida State University, Tallahassee, FL 32306, USA
| | - Jean-Michel Grisoni
- Institut de la Mer de Villefranche, IMEV, Sorbonne Université, Villefranche-sur-Mer, France
| | - Olivier Grosso
- Aix Marseille University, Université de Toulon, CNRS, IRD, MIO Marseille, France
| | - Jérémie Habasque
- CNRS, Univ Brest, IRD, Ifremer, UMR 6539, LEMAR, Plouzané, France
| | | | - Nathalie Leblond
- Institut de la Mer de Villefranche, IMEV, Sorbonne Université, Villefranche-sur-Mer, France
| | - Frédéric A C Le Moigne
- Aix Marseille University, Université de Toulon, CNRS, IRD, MIO Marseille, France
- CNRS, Univ Brest, IRD, Ifremer, UMR 6539, LEMAR, Plouzané, France
| | | | - Caroline Lory
- Aix Marseille University, Université de Toulon, CNRS, IRD, MIO Marseille, France
| | - Sandra Nunige
- Aix Marseille University, Université de Toulon, CNRS, IRD, MIO Marseille, France
| | | | - Andrea L Rizzo
- Istituto Nazionale di Geofisica e Vulcanologia, Sezione di Milano, Via Alfonso Corti 12, 20133 Milano, Italy
- Department of Earth and Environmental Sciences, University of Milano-Bicocca, Piazza della Scienza 4, 20126 Milan, Italy
| | | | - Chloé Tilliette
- Laboratoire d'Océanographie de Villefranche (LOV), Institut de la Mer de Villefranche, CNRS, Sorbonne Université, 06230 Villefranche-sur-Mer, France
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6
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Alzubaidi KRK, Mahdavi M, Dolati S, Yousefi M. Observation of increased levels of autophagy-related genes and proteins in women with preeclampsia: a clinical study. Mol Biol Rep 2023; 50:4831-4840. [PMID: 37039997 DOI: 10.1007/s11033-023-08385-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2023] [Accepted: 03/13/2023] [Indexed: 04/12/2023]
Abstract
BACKGROUND Preeclampsia is a type of pregnancy-related disease that is not fully understood underlying mechanisms of it till now. Reported results from autophagy-related studies in PE show some controversial roles of this mechanism in PE development and progression. In this study, we aimed to evaluate the autophagy process in preeclampsia women. MATERIALS AND METHODS Peripheral blood was taken from 50 preeclampsia women and 50 healthy pregnant women. After PBMC isolation, Total RNA and total protein were extracted from PBMCs to cDNA synthesis and real-time PCR and western blotting, respectively. Atg5, Atg7, beclin1, LC3B, FOXO1, FOXO3a, FOXO4, and FOXO6 genes were evaluated using real-time PCR. Atg5, beclin1, LC3B, and FOXO1 expression at the protein level was evaluated by the western blot technique. RESULTS Real-time PCR results showed an increased expression of Atg5, Atg7, beclin1, LC3B, FOXO1, FOXO3a, FOXO4, and FOXO6 genes in PE patients compared to the healthy pregnant women and also in LOPE patients in comparison with EOPE cases. Western blotting results revealed higher expression of Atg5, beclin1, LC3B, and FOXO1 proteins in PE women compared to healthy pregnant group and in LOPE patients in comparison with EOPE cases. Our findings revealed a positive correlation between proteinuria and protein levels of Atg5, beclin1, LC3B, and FOXO1 in LOPE patients. CONCLUSION Our investigation showed an elevated activation of autophagy in PE women in comparison with healthy pregnant women which is in controversy with some other studies. More targeted and comprehensive studies regarding the relationship of autophagy in pre-eclamptic women are needed.
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Affiliation(s)
| | - Majid Mahdavi
- Department of Biology, Faculty of Natural Science, University of Tabriz, Tabriz, Iran.
- Institute of Biochemistry and Biophysics, University of Tehran, Tehran, Iran.
| | - Sanam Dolati
- Physical Medicine and Rehabilitation Research Center, Aging Research Institute, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Mehdi Yousefi
- Department of Immunology, Faculty of Medicine, Medical School, Tabriz University of Medical Sciences, Tabriz, 5166614766, IR, Iran.
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Deka Dey A, Yousefiasl S, Kumar A, Dabbagh Moghaddam F, Rahimmanesh I, Samandari M, Jamwal S, Maleki A, Mohammadi A, Rabiee N, Cláudia Paiva‐Santos A, Tamayol A, Sharifi E, Makvandi P. miRNA-encapsulated abiotic materials and biovectors for cutaneous and oral wound healing: Biogenesis, mechanisms, and delivery nanocarriers. Bioeng Transl Med 2023; 8:e10343. [PMID: 36684081 PMCID: PMC9842058 DOI: 10.1002/btm2.10343] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Revised: 04/21/2022] [Accepted: 04/23/2022] [Indexed: 01/25/2023] Open
Abstract
MicroRNAs (miRNAs) as therapeutic agents have attracted increasing interest in the past decade owing to their significant effectiveness in treating a wide array of ailments. These polymerases II-derived noncoding RNAs act through post-transcriptional controlling of different proteins and their allied pathways. Like other areas of medicine, researchers have utilized miRNAs for managing acute and chronic wounds. The increase in the number of patients suffering from either under-healing or over-healing wound demonstrates the limited efficacy of the current wound healing strategies and dictates the demands for simpler approaches with greater efficacy. Various miRNA can be designed to induce pathway beneficial for wound healing. However, the proper design of miRNA and its delivery system for wound healing applications are still challenging due to their limited stability and intracellular delivery. Therefore, new miRNAs are required to be identified and their delivery strategy needs to be optimized. In this review, we discuss the diverse roles of miRNAs in various stages of wound healing and provide an insight on the most recent findings in the nanotechnology and biomaterials field, which might offer opportunities for the development of new strategies for this chronic condition. We also highlight the advances in biomaterials and delivery systems, emphasizing their challenges and resolutions for miRNA-based wound healing. We further review various biovectors (e.g., adenovirus and lentivirus) and abiotic materials such as organic and inorganic nanomaterials, along with dendrimers and scaffolds, as the delivery systems for miRNA-based wound healing. Finally, challenges and opportunities for translation of miRNA-based strategies into clinical applications are discussed.
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Affiliation(s)
| | - Satar Yousefiasl
- School of DentistryHamadan University of Medical SciencesHamadanIran
| | - Arun Kumar
- Chitkara College of PharmacyChitkara UniversityPunjabIndia
| | - Farnaz Dabbagh Moghaddam
- Department of Biology, Science and Research BranchIslamic Azad UniversityTehranIran
- Institute for Photonics and Nanotechnologies, National Research Council, Via Fosso del Cavaliere, 100RomeItaly
| | - Ilnaz Rahimmanesh
- Applied Physiology Research CenterCardiovascular Research Institute, Isfahan University of Medical SciencesIsfahanIran
| | | | - Sumit Jamwal
- Department of Psychiatry, Yale School of MedicineYale UniversityNew HavenConnecticutUSA
| | - Aziz Maleki
- Department of Pharmaceutical Nanotechnology, School of PharmacyZanjan University of Medical SciencesZanjanIran
- Zanjan Pharmaceutical Nanotechnology Research Center (ZPNRC)Zanjan University of Medical SciencesZanjanIran
- Cancer Research CentreShahid Beheshti University of Medical SciencesTehranIran
| | | | - Navid Rabiee
- Department of PhysicsSharif University of TechnologyTehranIran
- School of EngineeringMacquarie UniversitySydneyNew South WalesAustralia
| | - Ana Cláudia Paiva‐Santos
- Department of Pharmaceutical TechnologyFaculty of Pharmacy of the University of Coimbra, University of CoimbraCoimbraPortugal
- LAQV, REQUIMTE, Department of Pharmaceutical TechnologyFaculty of Pharmacy of the University of Coimbra, University of CoimbraCoimbraPortugal
| | - Ali Tamayol
- Department of Biomedical EngineeringUniversity of ConnecticutFarmingtonConnecticutUSA
| | - Esmaeel Sharifi
- Department of Tissue Engineering and Biomaterials, School of Advanced Medical Sciences and TechnologiesHamadan University of Medical SciencesHamadanIran
| | - Pooyan Makvandi
- Istituto Italiano di Tecnologia, Centre for Materials InterfacesPontederaItaly
- School of Chemistry, Damghan UniversityDamghanIran
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8
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Behnke J, Cai Y, Gu H, LaRoche J. Short-term response to iron resupply in an iron-limited open ocean diatom reveals rapid decay of iron-responsive transcripts. PLoS One 2023; 18:e0280827. [PMID: 36693065 PMCID: PMC9873189 DOI: 10.1371/journal.pone.0280827] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Accepted: 01/09/2023] [Indexed: 01/25/2023] Open
Abstract
In large areas of the ocean, iron concentrations are insufficient to promote phytoplankton growth. Numerous studies have been conducted to characterize the effect of iron on algae and how algae cope with fluctuating iron concentrations. Fertilization experiments in low-iron areas resulted primarily in diatom-dominated algal blooms, leading to laboratory studies on diatoms comparing low- and high-iron conditions. Here, we focus on the short-term temporal response following iron addition to an iron-starved open ocean diatom, Thalassiosira oceanica. We employed the NanoString platform and analyzed a high-resolution time series on 54 transcripts encoding proteins involved in photosynthesis, N-linked glycosylation, iron transport, as well as transcription factors. Nine transcripts were iron-responsive, with an immediate response to the addition of iron. The fastest response observed was the decrease in transcript levels of proteins involved in iron uptake, followed by an increase in transcript levels of iron-containing enzymes and a simultaneous decrease in the transcript levels of their iron-free replacement enzymes. The transcription inhibitor actinomycin D was used to understand the underlying mechanisms of the decrease of the iron-responsive transcripts and to determine their half-lives. Here, Mn-superoxide dismutase (Mn-SOD), plastocyanin (PETE), ferredoxin (PETF) and cellular repressor of EA1-stimulated genes (CREGx2) revealed longer than average half-lives. Four iron-responsive transcripts showed statistically significant differences in their decay rates between the iron-recovery samples and the actD treatment. These differences suggest regulatory mechanisms influencing gene transcription and mRNA stability. Overall, our study contributes towards a detailed understanding of diatom cell biology in the context of iron fertilization response and provides important observations to assess oceanic diatom responses following sudden changes in iron concentrations.
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Affiliation(s)
- Joerg Behnke
- Department of Biology, Dalhousie University, Halifax, Nova Scotia, Canada
- * E-mail: (JB); (JL)
| | - Yun Cai
- Department of Mathematics & Statistics, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Hong Gu
- Department of Mathematics & Statistics, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Julie LaRoche
- Department of Biology, Dalhousie University, Halifax, Nova Scotia, Canada
- * E-mail: (JB); (JL)
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9
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Babakhani P, Phenrat T, Baalousha M, Soratana K, Peacock CL, Twining BS, Hochella MF. Potential use of engineered nanoparticles in ocean fertilization for large-scale atmospheric carbon dioxide removal. NATURE NANOTECHNOLOGY 2022; 17:1342-1351. [PMID: 36443601 PMCID: PMC9747614 DOI: 10.1038/s41565-022-01226-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Accepted: 09/05/2022] [Indexed: 06/06/2023]
Abstract
Artificial ocean fertilization (AOF) aims to safely stimulate phytoplankton growth in the ocean and enhance carbon sequestration. AOF carbon sequestration efficiency appears lower than natural ocean fertilization processes due mainly to the low bioavailability of added nutrients, along with low export rates of AOF-produced biomass to the deep ocean. Here we explore the potential application of engineered nanoparticles (ENPs) to overcome these issues. Data from 123 studies show that some ENPs may enhance phytoplankton growth at concentrations below those likely to be toxic in marine ecosystems. ENPs may also increase bloom lifetime, boost phytoplankton aggregation and carbon export, and address secondary limiting factors in AOF. Life-cycle assessment and cost analyses suggest that net CO2 capture is possible for iron, SiO2 and Al2O3 ENPs with costs of 2-5 times that of conventional AOF, whereas boosting AOF efficiency by ENPs should substantially enhance net CO2 capture and reduce these costs. Therefore, ENP-based AOF can be an important component of the mitigation strategy to limit global warming.
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Affiliation(s)
- Peyman Babakhani
- Earth Surface Science Institute, School of Earth and Environment, University of Leeds, Leeds, UK
| | - Tanapon Phenrat
- Research Unit for Integrated Natural Resources Remediation and Reclamation (IN3R), Department of Civil Engineering, Faculty of Engineering, Naresuan University, Phitsanulok, Thailand
- Center of Excellence for Sustainability of Health, Environment and Industry (SHE&I), Faculty of Engineering, Naresuan University, Phitsanulok, Thailand
| | - Mohammed Baalousha
- Center for Environmental Nanoscience and Risk, Department of Environmental Health Sciences, Arnold School of Public Health, University of South Carolina, Columbia, SC, USA
| | - Kullapa Soratana
- Faculty of Logistics and Digital Supply Chain, Naresuan University, Phitsanulok, Thailand
| | - Caroline L Peacock
- Earth Surface Science Institute, School of Earth and Environment, University of Leeds, Leeds, UK
| | | | - Michael F Hochella
- Earth Systems Science Division, Energy and Environment Directorate, Pacific Northwest National Laboratory, Richland, WA, USA.
- Department of Geosciences, Virginia Tech, Blacksburg, VA, USA.
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10
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Dinasquet J, Landa M, Obernosterer I. SAR11 clade microdiversity and activity during the early spring blooms off Kerguelen Island, Southern Ocean. ENVIRONMENTAL MICROBIOLOGY REPORTS 2022; 14:907-916. [PMID: 36028477 DOI: 10.1111/1758-2229.13117] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Accepted: 08/10/2022] [Indexed: 05/17/2023]
Abstract
The ecology of the SAR11 clade, the most abundant bacterial group in the ocean, has been intensively studied in temperate and tropical regions, but its distribution remains largely unexplored in the Southern Ocean. Through amplicon sequencing of the 16S rRNA gene, we assessed the contribution of the SAR11 clade to bacterial community composition in the naturally iron fertilized region off Kerguelen Island. We investigated the upper 300 m at seven sites located in early spring phytoplankton blooms and at one high-nutrient low-chlorophyll site. Despite pronounced vertical patterns of the bacterioplankton assemblages, the SAR11 clade had high relative abundances at all depths and sites, averaging 40% (±15%) of the total community relative abundance. Micro-autoradiography combined with CARD-FISH further revealed that the clade had an overall stable contribution (45%-60% in surface waters) to bacterial biomass production (determined by 3 H-leucine incorporation) during different early bloom stages. The spatio-temporal partitioning of some of the SAR11 subclades suggests a niche specificity and periodic selection of different subclades in response to the fluctuating extreme conditions of the Southern Ocean. These observations improve our understanding of the ecology of the SAR11 clade and its implications in biogeochemical cycles in the rapidly changing Southern Ocean.
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Affiliation(s)
- Julie Dinasquet
- CNRS, Sorbonne Université, Laboratoire d'Océanographie Microbienne, LOMIC, Banyuls-sur-Mer, France
- Marine Biology Research Division and Climate, Atmospheric Science & Physical Oceanography Department, Scripps Institution of Oceanography, San Diego, California, USA
| | - Marine Landa
- CNRS, Sorbonne Université, Laboratoire d'Océanographie Microbienne, LOMIC, Banyuls-sur-Mer, France
- Sorbonne Université/Centre National de la Recherche Scientifique, UMR7144, Adaptation et Diversité en Milieu Marin, Station Biologique de Roscoff, Roscoff, France
| | - Ingrid Obernosterer
- CNRS, Sorbonne Université, Laboratoire d'Océanographie Microbienne, LOMIC, Banyuls-sur-Mer, France
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11
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Baranovskii DS, Klabukov ID, Arguchinskaya NV, Yakimova AO, Kisel AA, Yatsenko EM, Ivanov SA, Shegay PV, Kaprin AD. Adverse events, side effects and complications in mesenchymal stromal cell-based therapies. Stem Cell Investig 2022; 9:7. [PMID: 36393919 PMCID: PMC9659480 DOI: 10.21037/sci-2022-025] [Citation(s) in RCA: 36] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Accepted: 10/28/2022] [Indexed: 07/22/2023]
Abstract
Numerous clinical studies have shown a wide clinical potential of mesenchymal stromal cells (MSCs) application. However, recent experience has accumulated numerous reports of adverse events and side effects associated with MSCs therapy. Furthermore, the strategies and methods of MSCs therapy did not change significantly in recent decades despite the clinical impact and awareness of potential complications. An extended understanding of limitations could lead to a wider clinical implementation of safe cell therapies and avoid harmful approaches. Therefore, our objective was to summarize the possible negative effects observed during MSCs-based therapies. We were also aimed to discuss the risks caused by weaknesses in cell processing, including isolation, culturing, and storage. Cell processing and cell culture could dramatically influence cell population profile, change protein expression and cell differentiation paving the way for future negative effects. Long-term cell culture led to accumulation of chromosomal abnormalities. Overdosed antibiotics in culture media enhanced the risk of mycoplasma contamination. Clinical trials reported thromboembolism and fibrosis as the most common adverse events of MSCs therapy. Their delayed manifestation generally depends on the patient's individual phenotype and requires specific awareness during the clinical trials with obligatory inclusion in the patient' informed consents. Finally we prepared the safety checklist, recommended for clinical specialists before administration or planning of MSCs therapy.
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Affiliation(s)
- Denis S. Baranovskii
- National Medical Research Radiological Center of the Ministry of Health of the Russian Federation, Obninsk, Russia
- Peoples’ Friendship University of Russia (RUDN University), Moscow, Russia
| | - Ilya D. Klabukov
- National Medical Research Radiological Center of the Ministry of Health of the Russian Federation, Obninsk, Russia
- Peoples’ Friendship University of Russia (RUDN University), Moscow, Russia
- Obninsk Institute for Nuclear Power Engineering of the National Research Nuclear University MEPhI, Obninsk, Russia
| | - Nadezhda V. Arguchinskaya
- National Medical Research Radiological Center of the Ministry of Health of the Russian Federation, Obninsk, Russia
| | - Anna O. Yakimova
- National Medical Research Radiological Center of the Ministry of Health of the Russian Federation, Obninsk, Russia
| | - Anastas A. Kisel
- National Medical Research Radiological Center of the Ministry of Health of the Russian Federation, Obninsk, Russia
| | - Elena M. Yatsenko
- National Medical Research Radiological Center of the Ministry of Health of the Russian Federation, Obninsk, Russia
| | - Sergei A. Ivanov
- National Medical Research Radiological Center of the Ministry of Health of the Russian Federation, Obninsk, Russia
| | - Peter V. Shegay
- National Medical Research Radiological Center of the Ministry of Health of the Russian Federation, Obninsk, Russia
| | - Andrey D. Kaprin
- National Medical Research Radiological Center of the Ministry of Health of the Russian Federation, Obninsk, Russia
- Peoples’ Friendship University of Russia (RUDN University), Moscow, Russia
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12
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Laglera LM, Uskaikar H, Klaas C, Naqvi SWA, Wolf-Gladrow DA, Tovar-Sánchez A. Dissolved and particulate iron redox speciation during the LOHAFEX fertilization experiment. MARINE POLLUTION BULLETIN 2022; 184:114161. [PMID: 36179387 DOI: 10.1016/j.marpolbul.2022.114161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Revised: 09/15/2022] [Accepted: 09/17/2022] [Indexed: 06/16/2023]
Abstract
The redox speciation of iron was determined during the iron fertilization LOHAFEX and for the first time, the chemiluminescence assay of filtered and unfiltered samples was systematically compared. We hypothesize that higher chemiluminescence in unfiltered samples was caused by Fe(II) adsorbed onto biological particles. Dissolved and particulate Fe(II) increased in the mixed layer steadily 6-fold during the first two weeks and decreased back to initial levels by the end of LOHAFEX. Both Fe(II) forms did not show diel cycles downplaying the role of photoreduction. The chemiluminescence of unfiltered samples across the patch boundaries showed strong gradients, correlated significantly to biomass and the photosynthetic efficiency and were higher at night, indicative of a biological control. At 150 m deep, a secondary maximum of dissolved Fe(II) was associated with maxima of nitrite and ammonium despite high oxygen concentrations. We hypothesize that during LOHAFEX, iron redox speciation was mostly regulated by trophic interactions.
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Affiliation(s)
- Luis M Laglera
- FI-TRACE, Departamento de Química, Universidad de las Islas Baleares, Palma, Balearic Islands 07122, Spain; Laboratori Interdisciplinari sobre Canvi Climàtic, Universidad de las Islas Baleares, Palma, Balearic Islands 07122, Spain.
| | - Hema Uskaikar
- National Institute of Oceanography, Dona Paula, Goa, India
| | - Christine Klaas
- Alfred Wegener Institute for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany
| | | | - Dieter A Wolf-Gladrow
- Alfred Wegener Institute for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany
| | - Antonio Tovar-Sánchez
- Department of Ecology and Coastal Management, Andalusian Institute for Marine Science, ICMAN (CSIC), Campus Universitario Río San Pedro, Puerto Real, Cádiz, Spain
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13
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Disentangling the size-dependent redox reactivity of iron oxides using thermodynamic relationships. Proc Natl Acad Sci U S A 2022; 119:e2204673119. [PMID: 36161900 DOI: 10.1073/pnas.2204673119] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Nanoparticles often exhibit size-dependent redox reactivities, with smaller particles being more reactive in some cases, while less reactive in others. Predicting trends between redox reaction rates and particle sizes is often complicated because a particle's dimensions can simultaneously influence its aggregation state, reactive surface area, and thermodynamic properties. Here, we tested the hypothesis that interfacial redox reaction rates for nanoparticles with different sizes can be described with a single linear free-energy relationship (LFER) if size-dependent reactive surface areas and thermodynamic properties are properly considered. We tested this hypothesis using a well-known interfacial redox reaction: the reduction of nitrobenzene to aniline by iron-oxide-bound Fe2+. We measured the reduction potential (EH) values of nano-particulate hematite suspensions containing aqueous Fe2+ using mediated potentiometry and characterized the size and aggregation states of hematite samples at circumneutral pH values. We used the measured EH values to calculate surface energies and reactive surface areas using thermodynamic relationships. Nitrobenzene reduction rates were lower for smaller particles, despite their larger surface areas, due to their higher surface energies. When differences in surface areas and thermodynamic properties were considered, nitrobenzene reduction kinetics for all particle sizes was described with a LFER. Our results demonstrate that when Fe2+ serves as a reductant, an antagonistic effect exists, with smaller particles having larger reactive surface areas but also more positive reduction potentials. When Fe3+ serves as an oxidant, however, these two effects work in concert, which likely explains past discrepancies regarding how iron oxide particle sizes influence redox reaction rates.
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14
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Jackson RB, Abernethy S, Canadell JG, Cargnello M, Davis SJ, Féron S, Fuss S, Heyer AJ, Hong C, Jones CD, Damon Matthews H, O'Connor FM, Pisciotta M, Rhoda HM, de Richter R, Solomon EI, Wilcox JL, Zickfeld K. Atmospheric methane removal: a research agenda. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2021; 379:20200454. [PMID: 34565221 PMCID: PMC8473948 DOI: 10.1098/rsta.2020.0454] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Atmospheric methane removal (e.g. in situ methane oxidation to carbon dioxide) may be needed to offset continued methane release and limit the global warming contribution of this potent greenhouse gas. Because mitigating most anthropogenic emissions of methane is uncertain this century, and sudden methane releases from the Arctic or elsewhere cannot be excluded, technologies for methane removal or oxidation may be required. Carbon dioxide removal has an increasingly well-established research agenda and technological foundation. No similar framework exists for methane removal. We believe that a research agenda for negative methane emissions-'removal' or atmospheric methane oxidation-is needed. We outline some considerations for such an agenda here, including a proposed Methane Removal Model Intercomparison Project (MR-MIP). This article is part of a discussion meeting issue 'Rising methane: is warming feeding warming? (part 1)'.
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Affiliation(s)
- Robert B. Jackson
- Department of Earth System Science, Stanford University, Stanford, CA 94305-2210, USA
- Woods Institute for the Environment, and Precourt Institute for Energy, Stanford University, Stanford, CA 94305-2210, USA
| | - Sam Abernethy
- Department of Earth System Science, Stanford University, Stanford, CA 94305-2210, USA
- Department of Applied Physics, Stanford University, Stanford, CA, USA
| | - Josep G. Canadell
- Global Carbon Project, CSIRO Oceans and Atmosphere, Canberra, Australian Capital Territory 2601, Australia
| | - Matteo Cargnello
- Department of Chemical Engineering and SUNCAT Center for Interface Science and Catalysis, Stanford University, Stanford, CA, USA
| | - Steven J. Davis
- Department of Earth System Science, University of California at Irvine, Irvine, CA 92697, USA
| | - Sarah Féron
- Department of Earth System Science, Stanford University, Stanford, CA 94305-2210, USA
| | - Sabine Fuss
- Mercator Research Institute on Global Commons and Climate Change, Berlin, Germany
- Geographisches Institut, Humboldt Universität zu, Berlin, Germany
| | | | - Chaopeng Hong
- Department of Earth System Science, University of California at Irvine, Irvine, CA 92697, USA
| | - Chris D. Jones
- Met Office Hadley Centre, FitzRoy Road, Exeter EX1 3PB, UK
| | - H. Damon Matthews
- Department of Geography Planning and Environment, Concordia University, Montreal, Quebec, Canada
| | | | - Maxwell Pisciotta
- Chemical and Biomolecular Engineering Department, University of Pennsylvania, Pennsylvania, PA, USA
| | - Hannah M. Rhoda
- Department of Chemistry, Stanford University, Stanford, CA, USA
| | - Renaud de Richter
- Ecole Nationale Supérieure de Chimie de Montpellier, Montpellier, Languedoc-Roussillon FR, USA
| | - Edward I. Solomon
- Department of Chemistry, Stanford University, Stanford, CA, USA
- SLAC National Accelerator Laboratory, Stanford University, Stanford, CA, USA
| | - Jennifer L. Wilcox
- Chemical and Biomolecular Engineering Department, University of Pennsylvania, Pennsylvania, PA, USA
| | - Kirsten Zickfeld
- Department of Geography, Simon Fraser University, Burnaby, British Columbia, Canada V5A 1S6
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15
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Jones DC, Ceia FR, Murphy E, Delord K, Furness RW, Verdy A, Mazloff M, Phillips RA, Sagar PM, Sallée JB, Schreiber B, Thompson DR, Torres LG, Underwood PJ, Weimerskirch H, Xavier JC. Untangling local and remote influences in two major petrel habitats in the oligotrophic Southern Ocean. GLOBAL CHANGE BIOLOGY 2021; 27:5773-5785. [PMID: 34386992 DOI: 10.1111/gcb.15839] [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: 05/06/2021] [Revised: 07/29/2021] [Accepted: 08/02/2021] [Indexed: 06/13/2023]
Abstract
Ocean circulation connects geographically distinct ecosystems across a wide range of spatial and temporal scales via exchanges of physical and biogeochemical properties. Remote oceanographic processes can be especially important for ecosystems in the Southern Ocean, where the Antarctic Circumpolar Current transports properties across ocean basins through both advection and mixing. Recent tracking studies have indicated the existence of two large-scale, open ocean habitats in the Southern Ocean used by grey petrels (Procellaria cinerea) from two populations (i.e., Kerguelen and Antipodes islands) during their nonbreeding season for extended periods during austral summer (i.e., October to February). In this work, we use a novel combination of large-scale oceanographic observations, surface drifter data, satellite-derived primary productivity, numerical adjoint sensitivity experiments, and output from a biogeochemical state estimate to examine local and remote influences on these grey petrel habitats. Our aim is to understand the oceanographic features that control these isolated foraging areas and to evaluate their ecological value as oligotrophic open ocean habitats. We estimate the minimum local primary productivity required to support these populations to be much <1% of the estimated local primary productivity. The region in the southeast Indian Ocean used by the birds from Kerguelen is connected by circulation to the productive Kerguelen shelf. In contrast, the region in the south-central Pacific Ocean used by seabirds from the Antipodes is relatively isolated suggesting it is more influenced by local factors or the cumulative effects of many seasonal cycles. This work exemplifies the potential use of predator distributions and oceanographic data to highlight areas of the open ocean that may be more dynamic and productive than previously thought. Our results highlight the need to consider advective connections between ecosystems in the Southern Ocean and to re-evaluate the ecological relevance of oligotrophic Southern Ocean regions from a conservation perspective.
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Affiliation(s)
- Daniel C Jones
- British Antarctic Survey, Natural Environment Research Council, Cambridge, UK
| | - Filipe R Ceia
- Department of Life Sciences, Marine and Environmental Sciences Centre, University of Coimbra, Coimbra, Portugal
| | - Eugene Murphy
- British Antarctic Survey, Natural Environment Research Council, Cambridge, UK
| | - Karine Delord
- Centre d'Etudes Biologiques de Chizé, UMR 7372 du CNRS-La Rochelle Université, Villiers-en-Bois, France
| | - Robert W Furness
- Institute of Biodiversity Animal Health and Comparative Medicine, University of Glasgow, Glasgow, UK
| | - Ariane Verdy
- Scripps Institution of Oceanography, UCSD, San Diego, California, USA
| | - Matthew Mazloff
- Scripps Institution of Oceanography, UCSD, San Diego, California, USA
| | - Richard A Phillips
- British Antarctic Survey, Natural Environment Research Council, Cambridge, UK
| | - Paul M Sagar
- National Institute of Water and Atmospheric Research Ltd, Christchurch, New Zealand
| | | | - Ben Schreiber
- British Antarctic Survey, Natural Environment Research Council, Cambridge, UK
- Centre for Mathematical Sciences, University of Cambridge, Cambridge, UK
| | - David R Thompson
- National Institute of Water and Atmospheric Research Ltd, Wellington, New Zealand
| | - Leigh G Torres
- Geospatial Ecology of Marine Megafauna Lab, Department of Fisheries and Wildlife, Marine Mammal Institute, Oregon State University, Corvallis, Oregon, USA
| | - Philip J Underwood
- British Antarctic Survey, Natural Environment Research Council, Cambridge, UK
| | - Henri Weimerskirch
- Centre d'Etudes Biologiques de Chizé, UMR 7372 du CNRS-La Rochelle Université, Villiers-en-Bois, France
| | - José C Xavier
- British Antarctic Survey, Natural Environment Research Council, Cambridge, UK
- Department of Life Sciences, Marine and Environmental Sciences Centre, University of Coimbra, Coimbra, Portugal
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16
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Teng ZJ, Qin QL, Zhang W, Li J, Fu HH, Wang P, Lan M, Luo G, He J, McMinn A, Wang M, Chen XL, Zhang YZ, Chen Y, Li CY. Biogeographic traits of dimethyl sulfide and dimethylsulfoniopropionate cycling in polar oceans. MICROBIOME 2021; 9:207. [PMID: 34654476 PMCID: PMC8520302 DOI: 10.1186/s40168-021-01153-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Accepted: 08/04/2021] [Indexed: 06/13/2023]
Abstract
BACKGROUND Dimethyl sulfide (DMS) is the dominant volatile organic sulfur in global oceans. The predominant source of oceanic DMS is the cleavage of dimethylsulfoniopropionate (DMSP), which can be produced by marine bacteria and phytoplankton. Polar oceans, which represent about one fifth of Earth's surface, contribute significantly to the global oceanic DMS sea-air flux. However, a global overview of DMS and DMSP cycling in polar oceans is still lacking and the key genes and the microbial assemblages involved in DMSP/DMS transformation remain to be fully unveiled. RESULTS Here, we systematically investigated the biogeographic traits of 16 key microbial enzymes involved in DMS/DMSP cycling in 60 metagenomic samples from polar waters, together with 174 metagenome and 151 metatranscriptomes from non-polar Tara Ocean dataset. Our analyses suggest that intense DMS/DMSP cycling occurs in the polar oceans. DMSP demethylase (DmdA), DMSP lyases (DddD, DddP, and DddK), and trimethylamine monooxygenase (Tmm, which oxidizes DMS to dimethylsulfoxide) were the most prevalent bacterial genes involved in global DMS/DMSP cycling. Alphaproteobacteria (Pelagibacterales) and Gammaproteobacteria appear to play prominent roles in DMS/DMSP cycling in polar oceans. The phenomenon that multiple DMS/DMSP cycling genes co-occurred in the same bacterial genome was also observed in metagenome assembled genomes (MAGs) from polar oceans. The microbial assemblages from the polar oceans were significantly correlated with water depth rather than geographic distance, suggesting the differences of habitats between surface and deep waters rather than dispersal limitation are the key factors shaping microbial assemblages involved in DMS/DMSP cycling in polar oceans. CONCLUSIONS Overall, this study provides a global overview of the biogeographic traits of known bacterial genes involved in DMS/DMSP cycling from the Arctic and Antarctic oceans, laying a solid foundation for further studies of DMS/DMSP cycling in polar ocean microbiome at the enzymatic, metabolic, and processual levels. Video Abstract.
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Affiliation(s)
- Zhao-Jie Teng
- State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Qingdao, 266237, China
| | - Qi-Long Qin
- State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Qingdao, 266237, China
| | - Weipeng Zhang
- College of Marine Life Sciences, Institute for Advanced Ocean Study, Ocean University of China, Qingdao, 266003, China
| | - Jian Li
- State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Qingdao, 266237, China
| | - Hui-Hui Fu
- College of Marine Life Sciences, Institute for Advanced Ocean Study, Ocean University of China, Qingdao, 266003, China
- Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao, 266373, China
| | - Peng Wang
- College of Marine Life Sciences, Institute for Advanced Ocean Study, Ocean University of China, Qingdao, 266003, China
- Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao, 266373, China
| | - Musheng Lan
- The Key Laboratory for Polar Science MNR, Polar Research Institute of China, Shanghai, 200136, China
| | - Guangfu Luo
- The Key Laboratory for Polar Science MNR, Polar Research Institute of China, Shanghai, 200136, China
| | - Jianfeng He
- The Key Laboratory for Polar Science MNR, Polar Research Institute of China, Shanghai, 200136, China
| | - Andrew McMinn
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Tasmania, Australia
| | - Min Wang
- College of Marine Life Sciences, Institute for Advanced Ocean Study, Ocean University of China, Qingdao, 266003, China
| | - Xiu-Lan Chen
- College of Marine Life Sciences, Institute for Advanced Ocean Study, Ocean University of China, Qingdao, 266003, China
- Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao, 266373, China
| | - Yu-Zhong Zhang
- State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Qingdao, 266237, China
- College of Marine Life Sciences, Institute for Advanced Ocean Study, Ocean University of China, Qingdao, 266003, China
- Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao, 266373, China
| | - Yin Chen
- College of Marine Life Sciences, Institute for Advanced Ocean Study, Ocean University of China, Qingdao, 266003, China.
- School of Life Sciences, University of Warwick, Coventry, UK.
| | - Chun-Yang Li
- College of Marine Life Sciences, Institute for Advanced Ocean Study, Ocean University of China, Qingdao, 266003, China.
- Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao, 266373, China.
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17
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Pinkerton MH, Boyd PW, Deppeler S, Hayward A, Höfer J, Moreau S. Evidence for the Impact of Climate Change on Primary Producers in the Southern Ocean. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.592027] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Within the framework of the Marine Ecosystem Assessment for the Southern Ocean (MEASO), this paper brings together analyses of recent trends in phytoplankton biomass, primary production and irradiance at the base of the mixed layer in the Southern Ocean and summarises future projections. Satellite observations suggest that phytoplankton biomass in the mixed-layer has increased over the last 20 years in most (but not all) parts of the Southern Ocean, whereas primary production at the base of the mixed-layer has likely decreased over the same period. Different satellite models of primary production (Vertically Generalised versus Carbon Based Production Models) give different patterns and directions of recent change in net primary production (NPP). At present, the satellite record is not long enough to distinguish between trends and climate-related cycles in primary production. Over the next 100 years, Earth system models project increasing NPP in the water column in the MEASO northern and Antarctic zones but decreases in the Subantarctic zone. Low confidence in these projections arises from: (1) the difficulty in mapping supply mechanisms for key nutrients (silicate, iron); and (2) understanding the effects of multiple stressors (including irradiance, nutrients, temperature, pCO2, pH, grazing) on different species of Antarctic phytoplankton. Notwithstanding these uncertainties, there are likely to be changes to the seasonal patterns of production and the microbial community present over the next 50–100 years and these changes will have ecological consequences across Southern Ocean food-webs, especially on key species such as Antarctic krill and silverfish.
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18
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Therapeutic p28 peptide targets essential H1N1 influenza virus proteins: insights from docking and molecular dynamics simulations. Mol Divers 2021; 25:1929-1943. [PMID: 33575983 PMCID: PMC7877518 DOI: 10.1007/s11030-021-10193-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Accepted: 01/28/2021] [Indexed: 10/28/2022]
Abstract
The H1N1 influenza virus causes a severe disease that affects the human respiratory tract leading to millions of deaths every year. At present, certain vaccines and few drugs are used to control the virus during seasonal outbreaks. However, high mutation rates and genetic reassortment make it challenging to prevent and mitigate outbreaks, leading to pandemics. Thus, alternate therapies are required for its management and control. Here, we report that a bacterial protein, azurin, and its peptide derivatives p18 and p28 target critical proteins of the influenza virus in an effective manner. The molecular docking studies show that the p28 peptide could target C-PB1, NS1-ED, PB2-CBD, PB2-RBD, NP, and PA proteins. These complexes were further subjected to the simulation of molecular dynamics and binding free energy calculations. The data indicate that p28 has an unusually high affinity and forms stable complexes with the viral proteins C-PB1, PB2-CBD, PB2-RBD, and NP. We suggest that the azurin derivative p28 peptide can act as an anti-influenza agent as it can bind to multiple targets and neutralize the virus. Additional experimental studies need to be conducted to evaluate its safety and efficacy as an anti-H1N1 molecule.
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19
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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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20
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Struve T, Pahnke K, Lamy F, Wengler M, Böning P, Winckler G. A circumpolar dust conveyor in the glacial Southern Ocean. Nat Commun 2020; 11:5655. [PMID: 33168803 PMCID: PMC7652835 DOI: 10.1038/s41467-020-18858-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Accepted: 09/14/2020] [Indexed: 11/22/2022] Open
Abstract
The increased flux of soluble iron (Fe) to the Fe-deficient Southern Ocean by atmospheric dust is considered to have stimulated the net primary production and carbon export, thus promoting atmospheric CO2 drawdown during glacial periods. Yet, little is known about the sources and transport pathways of Southern Hemisphere dust during the Last Glacial Maximum (LGM). Here we show that Central South America (~24‒32°S) contributed up to ~80% of the dust deposition in the South Pacific Subantarctic Zone via efficient circum-Antarctic dust transport during the LGM, whereas the Antarctic Zone was dominated by dust from Australia. This pattern is in contrast to the modern/Holocene pattern, when South Pacific dust fluxes are thought to be primarily supported by Australian sources. Our findings reveal that in the glacial Southern Ocean, Fe fertilization critically relies on the dynamic interaction of changes in dust-Fe sources in Central South America with the circumpolar westerly wind system. Dust deposition brings iron that fuels ocean productivity, a connection impacting climate over geological time. Here the authors use sediment cores to show that in contrast to dynamics today, during the last glacial maximum westerly winds shuttled dust from Australia and South America around Antarctica and into the South Pacific.
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Affiliation(s)
- Torben Struve
- Marine Isotope Geochemistry, Institute for Chemistry and Biology of the Marine Environment (ICBM), University of Oldenburg, 26129, Oldenburg, Germany.
| | - Katharina Pahnke
- Marine Isotope Geochemistry, Institute for Chemistry and Biology of the Marine Environment (ICBM), University of Oldenburg, 26129, Oldenburg, Germany
| | - Frank Lamy
- Alfred Wegener Institute for Polar and Marine Research, 27568, Bremerhaven, Germany
| | - Marc Wengler
- Alfred Wegener Institute for Polar and Marine Research, 27568, Bremerhaven, Germany
| | - Philipp Böning
- Marine Isotope Geochemistry, Institute for Chemistry and Biology of the Marine Environment (ICBM), University of Oldenburg, 26129, Oldenburg, Germany
| | - Gisela Winckler
- Lamont-Doherty Earth Observatory of Columbia University, Palisades, New York, 10964, USA.,Department of Earth and Environmental Sciences, Columbia University, New York, New York, 10027, USA
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21
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Dillon ML, Hawes I, Jungblut AD, Mackey TJ, Eisen JA, Doran PT, Sumner DY. Environmental control on the distribution of metabolic strategies of benthic microbial mats in Lake Fryxell, Antarctica. PLoS One 2020; 15:e0231053. [PMID: 32282803 PMCID: PMC7153904 DOI: 10.1371/journal.pone.0231053] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Accepted: 03/15/2020] [Indexed: 11/19/2022] Open
Abstract
Ecological theories posit that heterogeneity in environmental conditions greatly affects community structure and function. However, the degree to which ecological theory developed using plant- and animal-dominated systems applies to microbiomes is unclear. Investigating the metabolic strategies found in microbiomes are particularly informative for testing the universality of ecological theories because microorganisms have far wider metabolic capacity than plants and animals. We used metagenomic analyses to explore the relationships between the energy and physicochemical gradients in Lake Fryxell and the metabolic capacity of its benthic microbiome. Statistical analysis of the relative abundance of metabolic marker genes and gene family diversity shows that oxygenic photosynthesis, carbon fixation, and flavin-based electron bifurcation differentiate mats growing in different environmental conditions. The pattern of gene family diversity points to the likely importance of temporal environmental heterogeneity in addition to resource gradients. Overall, we found that the environmental heterogeneity of photosynthetically active radiation (PAR) and oxygen concentration ([O2]) in Lake Fryxell provide the framework by which metabolic diversity and composition of the community is structured, in accordance with its phylogenetic structure. The organization of the resulting microbial ecosystems are consistent with the maximum power principle and the species sorting model.
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Affiliation(s)
- Megan L. Dillon
- Ecology Department, Lawrence Berkeley National Laboratory, Berkeley, CA, United States of America
- Department of Earth and Planetary Sciences, University of California, Davis, Davis, California, United States of America
| | - Ian Hawes
- Coastal Marine Field Station, University of Waikato, Hamilton, Waikato, New Zealand
| | - Anne D. Jungblut
- Life Sciences Department, Natural History Museum, London, England, United Kingdom
| | - Tyler J. Mackey
- Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Jonathan A. Eisen
- Department of Evolution and Ecology, University of California, Davis, Davis, California, United States of America
| | - Peter T. Doran
- Geology and Geophysics Department, Louisiana State University, Baton Rouge, Louisiana, United States of America
| | - Dawn Y. Sumner
- Department of Earth and Planetary Sciences, University of California, Davis, Davis, California, United States of America
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22
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Hopwood MJ, Carroll D, Höfer J, Achterberg EP, Meire L, Le Moigne FAC, Bach LT, Eich C, Sutherland DA, González HE. Highly variable iron content modulates iceberg-ocean fertilisation and potential carbon export. Nat Commun 2019; 10:5261. [PMID: 31748607 PMCID: PMC6868171 DOI: 10.1038/s41467-019-13231-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Accepted: 10/29/2019] [Indexed: 11/17/2022] Open
Abstract
Marine phytoplankton growth at high latitudes is extensively limited by iron availability. Icebergs are a vector transporting the bioessential micronutrient iron into polar oceans. Therefore, increasing iceberg fluxes due to global warming have the potential to increase marine productivity and carbon export, creating a negative climate feedback. However, the magnitude of the iceberg iron flux, the subsequent fertilization effect and the resultant carbon export have not been quantified. Using a global analysis of iceberg samples, we reveal that iceberg iron concentrations vary over 6 orders of magnitude. Our results demonstrate that, whilst icebergs are the largest source of iron to the polar oceans, the heterogeneous iron distribution within ice moderates iron delivery to offshore waters and likely also affects the subsequent ocean iron enrichment. Future marine productivity may therefore be not only sensitive to increasing total iceberg fluxes, but also to changing iceberg properties, internal sediment distribution and melt dynamics.
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Affiliation(s)
- Mark J Hopwood
- GEOMAR, Helmholtz Centre for Ocean Research Kiel, Kiel, Germany.
| | - Dustin Carroll
- Moss Landing Marine Laboratories, San José State University, Moss Landing, CA, USA
| | - Juan Höfer
- Escuela de Ciencias del Mar, Pontificia Universidad Católica de Valparaíso, Valparaíso, Chile
- Centro FONDAP de Investigación en Dinámica de Ecosistemas Marinos de Altas Latitudes (IDEAL), Universidad Austral de Chile, Valdivia, Chile
| | | | - Lorenz Meire
- Royal Netherlands Institute for Sea Research, and Utrecht University, Yerseke, The Netherlands
- Greenland Climate Research Centre, Greenland Institute of Natural Resources, Nuuk, Greenland
| | - Frédéric A C Le Moigne
- Mediterranean Institute of Oceanography, UM110, CNRS, IRD, Aix Marseille Université Marseille, Marseille, France
| | - Lennart T Bach
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Tasmania, Australia
| | - Charlotte Eich
- Royal Netherlands Institute for Sea Research, and University of Amsterdam, Texel, The Netherlands
| | | | - Humberto E González
- Centro FONDAP de Investigación en Dinámica de Ecosistemas Marinos de Altas Latitudes (IDEAL), Universidad Austral de Chile, Valdivia, Chile
- Instituto de Ciencias Marinas y Limnológicas, Universidad Austral de Chile, Casilla 567, Valdivia, Chile
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23
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Zamanillo M, Ortega-Retuerta E, Nunes S, Estrada M, Sala MM, Royer SJ, López-Sandoval DC, Emelianov M, Vaqué D, Marrasé C, Simó R. Distribution of transparent exopolymer particles (TEP) in distinct regions of the Southern Ocean. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 691:736-748. [PMID: 31325871 DOI: 10.1016/j.scitotenv.2019.06.524] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Revised: 06/28/2019] [Accepted: 06/30/2019] [Indexed: 06/10/2023]
Abstract
Transparent exopolymer particles (TEP) are an abundant class of suspended organic particles, mainly formed by polysaccharides, which play important roles in biogeochemical and ecological processes in the ocean. In this study we investigated horizontal and vertical TEP distributions (within the euphotic layer, including the upper surface) and their short-term variability along with a suite of environmental and biological variables in four distinct regions of the Southern Ocean. TEP concentrations in the surface (4 m) averaged 102.3 ± 40.4 μg XG eq. L-1 and typically decreased with depth. Chlorophyll a (Chl a) concentration was a better predictor of TEP variability across the horizontal (R2 = 0.66, p < 0.001) and vertical (R2 = 0.74, p < 0.001) scales than prokaryotic heterotrophic abundance and production. Incubation experiments further confirmed the main role of phytoplankton as TEP producers. The highest surface TEP concentrations were found north of the South Orkney Islands (144.4 ± 21.7 μg XG eq. L-1), where the phytoplankton was dominated by cryptophytes and haptophytes; however, the highest TEP:Chl a ratios were found south of these islands (153.4 ± 29.8 μg XG eq (μg Chl a)-1, compared to a mean of 79.3 ± 54.9 μg XG eq (μg Chl a)-1 in the whole cruise, in association with haptophyte dominance, proximity of sea ice and high exposure to solar radiation. TEP were generally enriched in the upper surface (10 cm) respect to 4 m, despite a lack of biomass enrichment, suggesting either upward transport by positive buoyancy or bubble scavenging, or higher production at the upper surface by light stress or aggregation. TEP concentrations did not present any significant cyclic diel pattern. Altogether, our results suggest that photobiological stress, sea ice melt and turbulence add to phytoplankton productivity in driving TEP distribution across the Antarctic Peninsula area and Atlantic sector of the Southern Ocean.
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Affiliation(s)
- Marina Zamanillo
- Biologia Marina i Oceanografia, Institut de Ciències del Mar, CSIC, Barcelona, Catalonia, Spain
| | - Eva Ortega-Retuerta
- Biologia Marina i Oceanografia, Institut de Ciències del Mar, CSIC, Barcelona, Catalonia, Spain; CNRS, Sorbonne Université, UMR 7621, Laboratoire d'Océanographie Microbienne, Banyuls-sur-Mer, France
| | - Sdena Nunes
- Biologia Marina i Oceanografia, Institut de Ciències del Mar, CSIC, Barcelona, Catalonia, Spain
| | - Marta Estrada
- Biologia Marina i Oceanografia, Institut de Ciències del Mar, CSIC, Barcelona, Catalonia, Spain
| | - María Montserrat Sala
- Biologia Marina i Oceanografia, Institut de Ciències del Mar, CSIC, Barcelona, Catalonia, Spain
| | - Sarah-Jeanne Royer
- Biologia Marina i Oceanografia, Institut de Ciències del Mar, CSIC, Barcelona, Catalonia, Spain; Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA 92093, USA
| | - Daffne C López-Sandoval
- Biologia Marina i Oceanografia, Institut de Ciències del Mar, CSIC, Barcelona, Catalonia, Spain; Red Sea Research Center (RSRC), King Abdullah University of Science and Techonolgy (KAUST), Thuwal, Saudi Arabia
| | - Mikhail Emelianov
- Biologia Marina i Oceanografia, Institut de Ciències del Mar, CSIC, Barcelona, Catalonia, Spain
| | - Dolors Vaqué
- Biologia Marina i Oceanografia, Institut de Ciències del Mar, CSIC, Barcelona, Catalonia, Spain
| | - Cèlia Marrasé
- Biologia Marina i Oceanografia, Institut de Ciències del Mar, CSIC, Barcelona, Catalonia, Spain
| | - Rafel Simó
- Biologia Marina i Oceanografia, Institut de Ciències del Mar, CSIC, Barcelona, Catalonia, Spain.
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24
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Wadham JL, Hawkings JR, Tarasov L, Gregoire LJ, Spencer RGM, Gutjahr M, Ridgwell A, Kohfeld KE. Ice sheets matter for the global carbon cycle. Nat Commun 2019; 10:3567. [PMID: 31417076 PMCID: PMC6695407 DOI: 10.1038/s41467-019-11394-4] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Accepted: 07/09/2019] [Indexed: 11/09/2022] Open
Abstract
The cycling of carbon on Earth exerts a fundamental influence upon the greenhouse gas content of the atmosphere, and hence global climate over millennia. Until recently, ice sheets were viewed as inert components of this cycle and largely disregarded in global models. Research in the past decade has transformed this view, demonstrating the existence of uniquely adapted microbial communities, high rates of biogeochemical/physical weathering in ice sheets and storage and cycling of organic carbon (>104 Pg C) and nutrients. Here we assess the active role of ice sheets in the global carbon cycle and potential ramifications of enhanced melt and ice discharge in a warming world.
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Affiliation(s)
- J L Wadham
- University of Bristol, Bristol, BS8 1TH, UK.
| | - J R Hawkings
- National High Magnetic Field Lab and Earth, Ocean and Atmospheric Sciences, Florida State University, Tallahassee, FL, 32306, USA
- German Research Centre for Geosciences GFZ, 14473, Potsdam, Germany
| | - L Tarasov
- Memorial University, St. John's, NF, A1B 3X9, Canada
| | | | - R G M Spencer
- National High Magnetic Field Lab and Earth, Ocean and Atmospheric Sciences, Florida State University, Tallahassee, FL, 32306, USA
| | | | - A Ridgwell
- University of California, Riverside, CA, 94720, USA
| | - K E Kohfeld
- Simon Fraser University, Burnaby, BC, 8888, Canada
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25
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Debeljak P, Toulza E, Beier S, Blain S, Obernosterer I. Microbial iron metabolism as revealed by gene expression profiles in contrasted Southern Ocean regimes. Environ Microbiol 2019; 21:2360-2374. [PMID: 30958628 PMCID: PMC6618146 DOI: 10.1111/1462-2920.14621] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Revised: 03/18/2019] [Accepted: 04/01/2019] [Indexed: 11/28/2022]
Abstract
Iron (Fe) is a limiting nutrient in large regions of the ocean, but the strategies of prokaryotes to cope with this micronutrient are poorly known. Using a gene-specific approach from metatranscriptomics data, we investigated seven Fe-related metabolic pathways in microbial communities from high nutrient low chlorophyll and naturally Fe-fertilized waters in the Southern Ocean. We observed major differences in the contribution of prokaryotic groups at different taxonomic levels to transcripts encoding Fe-uptake mechanisms, intracellular Fe storage and replacement and Fe-related pathways in the tricarboxylic acid (TCA) cycle. The composition of the prokaryotic communities contributing to the transcripts of a given Fe-related pathway was overall independent of the in situ Fe supply, indicating that microbial taxa utilize distinct Fe-related metabolic processes. Only a few prokaryotic groups contributed to the transcripts of more than one Fe-uptake mechanism, suggesting limited metabolic versatility. Taxa-specific expression of individual genes varied among prokaryotic groups and was substantially higher for all inspected genes in Fe-limited as compared to naturally fertilized waters, indicating the link between transcriptional state and Fe regime. Different metabolic strategies regarding low Fe concentrations in the Southern Ocean are discussed for two abundant prokaryotic groups, Pelagibacteraceae and Flavobacteriaceae.
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Affiliation(s)
- Pavla Debeljak
- Sorbonne UniversitéCNRS, Laboratoire d'Océanographie Microbienne, LOMICF‐66650 Banyuls/merFrance
- Department of Limnology and Bio‐OceanographyUniversity of Vienna, A‐1090ViennaAustria
| | - Eve Toulza
- Université Perpignan Via DomitiaIHPE UMR 5244, CNRS, IFREMER, Univ. Montpellier, F‐66860PerpignanFrance
| | - Sara Beier
- Leibniz Institute for Baltic Sea ResearchWarnemündeGermany
| | - Stephane Blain
- Sorbonne UniversitéCNRS, Laboratoire d'Océanographie Microbienne, LOMICF‐66650 Banyuls/merFrance
| | - Ingrid Obernosterer
- Sorbonne UniversitéCNRS, Laboratoire d'Océanographie Microbienne, LOMICF‐66650 Banyuls/merFrance
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26
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Affiliation(s)
- Qianshuo Zhao
- Institute of Marine Science University of Auckland Auckland New Zealand
| | - Mark J. Costello
- Institute of Marine Science University of Auckland Auckland New Zealand
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27
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28
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Baltar F, Gutiérrez-Rodríguez A, Meyer M, Skudelny I, Sander S, Thomson B, Nodder S, Middag R, Morales SE. Specific Effect of Trace Metals on Marine Heterotrophic Microbial Activity and Diversity: Key Role of Iron and Zinc and Hydrocarbon-Degrading Bacteria. Front Microbiol 2018; 9:3190. [PMID: 30619234 PMCID: PMC6306045 DOI: 10.3389/fmicb.2018.03190] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Accepted: 12/10/2018] [Indexed: 01/26/2023] Open
Abstract
Marine microbes are an important control on the biogeochemical cycling of trace metals, but simultaneously, these metals can control the growth of microorganisms and the cycling of major nutrients like C and N. However, studies on the response/limitation of microorganisms to trace metals have traditionally focused on the response of autotrophic phytoplankton to Fe fertilization. Few reports are available on the response of heterotrophic prokaryotes to Fe, and even less to other biogeochemically relevant metals. We performed the first study coupling dark incubations with next generation sequencing to specifically target the functional and phylogenetic response of heterotrophic prokaryotes to Fe enrichment. Furthermore, we also studied their response to Co, Mn, Ni, Zn, Cu (individually and mixed), using surface and deep samples from either coastal or open-ocean waters. Heterotrophic prokaryotic activity was stimulated by Fe in surface open–ocean, as well as in coastal, and deep open-ocean waters (where Zn also stimulated). The most susceptible populations to trace metals additions were uncultured bacteria (e.g., SAR324, SAR406, NS9, and DEV007). Interestingly, hydrocarbon-degrading bacteria (e.g., Thalassolituus, Marinobacter, and Oleibacter) benefited the most from metal addition across all waters (regions/depths) revealing a predominant role in the cycling of metals and organic matter in the ocean.
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Affiliation(s)
- Federico Baltar
- Department of Limnology and Bio-Oceanography, Center of Functional Ecology, University of Vienna, Vienna, Austria.,Department of Marine Science, University of Otago, Dunedin, New Zealand.,National Institute of Water and Atmospheric Research (NIWA)/University of Otago Research Centre for Oceanography, University of Otago, Dunedin, New Zealand
| | | | - Moana Meyer
- Department of Limnology and Bio-Oceanography, Center of Functional Ecology, University of Vienna, Vienna, Austria.,Department of Marine Science, University of Otago, Dunedin, New Zealand
| | - Isadora Skudelny
- Department of Limnology and Bio-Oceanography, Center of Functional Ecology, University of Vienna, Vienna, Austria.,Department of Marine Science, University of Otago, Dunedin, New Zealand
| | - Sylvia Sander
- National Institute of Water and Atmospheric Research (NIWA)/University of Otago Research Centre for Oceanography, University of Otago, Dunedin, New Zealand.,Environment Laboratories, Department of Nuclear Sciences and Applications, International Atomic Energy Agency (IAEA), Monaco, Monaco
| | - Blair Thomson
- Department of Limnology and Bio-Oceanography, Center of Functional Ecology, University of Vienna, Vienna, Austria.,Department of Marine Science, University of Otago, Dunedin, New Zealand
| | - Scott Nodder
- National Institute of Water and Atmospheric Research, Wellington, New Zealand
| | - Rob Middag
- Department of Ocean Systems, Royal Netherlands Institute for Sea Research, Yerseke, Netherlands
| | - Sergio E Morales
- Department of Microbiology and Immunology, Otago School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
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29
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Enhanced ocean-atmosphere carbon partitioning via the carbonate counter pump during the last deglacial. Nat Commun 2018; 9:2396. [PMID: 29921874 PMCID: PMC6008475 DOI: 10.1038/s41467-018-04625-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Accepted: 05/08/2018] [Indexed: 11/18/2022] Open
Abstract
Several synergistic mechanisms were likely involved in the last deglacial atmospheric pCO2 rise. Leading hypotheses invoke a release of deep-ocean carbon through enhanced convection in the Southern Ocean (SO) and concomitant decreased efficiency of the global soft-tissue pump (STP). However, the temporal evolution of both the STP and the carbonate counter pump (CCP) remains unclear, thus preventing the evaluation of their contributions to the pCO2 rise. Here we present sedimentary coccolith records combined with export production reconstructions from the Subantarctic Pacific to document the leverage the SO biological carbon pump (BCP) has imposed on deglacial pCO2. Our data suggest a weakening of BCP during the phases of carbon outgassing, due in part to an increased CCP along with higher surface ocean fertility and elevated [CO2aq]. We propose that reduced BCP efficiency combined with enhanced SO ventilation played a major role in propelling the Earth out of the last ice age. The contribution of the carbonate counter pump (CCP) to the last deglacial atmospheric CO2 rise has yet been largely ignored. Here, the authors show that an increased CCP in the Subantarctic Pacific along with high surface ocean fertility and [CO2aq], contributed in propelling the Earth out of the last ice age.
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30
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Tarling GA, Ward P, Thorpe SE. Spatial distributions of Southern Ocean mesozooplankton communities have been resilient to long-term surface warming. GLOBAL CHANGE BIOLOGY 2018; 24:132-142. [PMID: 28850764 DOI: 10.1111/gcb.13834] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Accepted: 06/23/2017] [Indexed: 06/07/2023]
Abstract
The biogeographic response of oceanic planktonic communities to climatic change has a large influence on the future stability of marine food webs and the functioning of global biogeochemical cycles. Temperature plays a pivotal role in determining the distribution of these communities and ocean warming has the potential to cause major distributional shifts, particularly in polar regions where the thermal envelope is narrow. We considered the impact of long-term ocean warming on the spatial distribution of Southern Ocean mesozooplankton communities through examining plankton abundance in relation to sea surface temperature between two distinct periods, separated by around 60 years. Analyses considered 16 dominant mesozooplankton taxa (in terms of biomass and abundance) in the southwest Atlantic sector of the Southern Ocean, from net samples and in situ temperature records collected during the Discovery Investigations (1926-1938) and contemporary campaigns (1996-2013). Sea surface temperature was found to have increased significantly by 0.74°C between the two eras. The corresponding sea surface temperature at which community abundance peaked was also significantly higher in contemporary times, by 0.98°C. Spatial projections indicated that the geographical location of community peak abundance had remained the same between the two eras despite the poleward advance of sea surface isotherms. If the community had remained within the same thermal envelope as in the 1920s-1930s, community peak abundance would be 500 km further south in the contemporary era. Studies in the northern hemisphere have found that dominant taxa, such as calanoid copepods, have conserved their thermal niches and tracked surface isotherms polewards. The fact that this has not occurred in the Southern Ocean suggests that other selective pressures, particularly food availability and the properties of underlying water masses, place greater constraints on spatial distributions in this region. It further demonstrates that this community is thermally resilient to present levels of sea surface warming.
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Affiliation(s)
- Geraint A Tarling
- British Antarctic Survey, Natural Environment Research Council, Cambridge, UK
| | - Peter Ward
- British Antarctic Survey, Natural Environment Research Council, Cambridge, UK
| | - Sally E Thorpe
- British Antarctic Survey, Natural Environment Research Council, Cambridge, UK
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31
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Annual particulate matter and diatom export in a high nutrient, low chlorophyll area of the Southern Ocean. Polar Biol 2017. [DOI: 10.1007/s00300-017-2167-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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32
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Tagliabue A, Bowie AR, Boyd PW, Buck KN, Johnson KS, Saito MA. The integral role of iron in ocean biogeochemistry. Nature 2017; 543:51-59. [PMID: 28252066 DOI: 10.1038/nature21058] [Citation(s) in RCA: 147] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Accepted: 12/06/2016] [Indexed: 11/09/2022]
Abstract
The micronutrient iron is now recognized to be important in regulating the magnitude and dynamics of ocean primary productivity, making it an integral component of the ocean's biogeochemical cycles. In this Review, we discuss how a recent increase in observational data for this trace metal has challenged the prevailing view of the ocean iron cycle. Instead of focusing on dust as the major iron source and emphasizing iron's tight biogeochemical coupling to major nutrients, a more complex and diverse picture of the sources of iron, its cycling processes and intricate linkages with the ocean carbon and nitrogen cycles has emerged.
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Affiliation(s)
- Alessandro Tagliabue
- Department of Earth Ocean and Ecological Sciences, School of Environmental Sciences, University of Liverpool, Liverpool, UK
| | - Andrew R Bowie
- Institute for Marine and Antarctic Studies and Antarctic Climate and Ecosystems Co-operative Research Centre, University of Tasmania, Hobart, Australia
| | - Philip W Boyd
- Institute for Marine and Antarctic Studies and Antarctic Climate and Ecosystems Co-operative Research Centre, University of Tasmania, Hobart, Australia
| | | | | | - Mak A Saito
- Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, USA
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33
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The potential role of Antarctic krill faecal pellets in efficient carbon export at the marginal ice zone of the South Orkney Islands in spring. Polar Biol 2017; 40:2001-2013. [PMID: 32009725 PMCID: PMC6961482 DOI: 10.1007/s00300-017-2118-z] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2016] [Revised: 03/24/2017] [Accepted: 03/26/2017] [Indexed: 11/23/2022]
Abstract
Antarctic krill (Euphausia superba) play a central role in the food web of the Southern Ocean, forming a link between primary production and large predators. Krill produce large, faecal pellets (FP) which can form a large component of mesopelagic particulate organic carbon (POC) fluxes. However, the patchy distribution of krill swarms, highly variable pellet composition, and variable sinking and attenuation rates means that these episodic, but potentially large, carbon fluxes are difficult to sample or model. We measured particle flux and type using Marine Snow Catchers (MSC) in the marginal ice zone near the South Orkneys, Antarctica. Krill FP were the dominant component of the POC flux in the upper 200 m (typically 60–85%). FP sinking velocities measured onboard were highly variable (15–507 m d−1) but overall high, with mean equivalent velocities of 172, 267, and 161 m d−1 at our three stations. The high numbers of krill FP sinking through the mesopelagic suggest that krill FP can be transferred efficiently and/or that rates of krill FP production are high. We compared our direct MSC-derived estimates of krill FP POC flux (33–154 mg C m−2 d−1) and attenuation to estimates of krill FP production based on previous measurements of krill density and literature FP egestion rates, and estimated net krill FP attenuation rates in the upper mesopelagic. Calculated attenuation rates are sensitive to krill densities in the overlying water column but suggest that krill FP could be transferred efficiently through the upper mesopelagic, and, in agreement with our MSC attenuation estimates, could make large contributions to bathypelagic POC fluxes. Our study contrasts with some others which suggest rapid FP attenuation, highlighting the need for further work to constrain attenuation rates and assess how important the contribution of Antarctic krill FP could be to the Southern Ocean biological carbon pump.
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Boyd PW, Bressac M. Developing a test-bed for robust research governance of geoengineering: the contribution of ocean iron biogeochemistry. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2016; 374:20150299. [PMID: 29035263 PMCID: PMC5069533 DOI: 10.1098/rsta.2015.0299] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 08/30/2016] [Indexed: 05/13/2023]
Abstract
Geoengineering to mitigate climate change has long been proposed, but remains nebulous. Exploration of the feasibility of geoengineering first requires the development of research governance to move beyond the conceptual towards scientifically designed pilot studies. Fortuitously, 12 mesoscale (approx. 1000 km2) iron enrichments, funded to investigate how ocean iron biogeochemistry altered Earth's carbon cycle in the geological past, provide proxies to better understand the benefits and drawbacks of geoengineering. The utility of these iron enrichments in the geoengineering debate is enhanced by the GEOTRACES global survey. Here, we outline how GEOTRACES surveys and process studies can provide invaluable insights into geoengineering. Surveys inform key unknowns including the regional influence and magnitude of modes of iron supply, and stimulate iron biogeochemical modelling. These advances will enable quantification of interannual variability of iron supply to assess whether any future purposeful multi-year iron-fertilization meets the principle of 'additionality' (sensu Kyoto protocol). Process studies address issues including upscaling of geoengineering, and how differing iron-enrichment strategies could stimulate wide-ranging biogeochemical outcomes. In summary, the availability of databases on both mesoscale iron-enrichment studies and the GEOTRACES survey, along with modelling, policy initiatives and legislation have positioned the iron-enrichment approach as a robust multifaceted test-bed to assess proposed research into climate intervention.This article is part of the themed issue 'Biological and climatic impacts of ocean trace element chemistry'.
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Affiliation(s)
- Philip W Boyd
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Tasmania, Australia
- Antarctic Climate and Ecosystems Collaborative Research Centre, University of Tasmania, Hobart, Tasmania, Australia
| | - Matthieu Bressac
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Tasmania, Australia
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Charette MA, Lam PJ, Lohan MC, Kwon EY, Hatje V, Jeandel C, Shiller AM, Cutter GA, Thomas A, Boyd PW, Homoky WB, Milne A, Thomas H, Andersson PS, Porcelli D, Tanaka T, Geibert W, Dehairs F, Garcia-Orellana J. Coastal ocean and shelf-sea biogeochemical cycling of trace elements and isotopes: lessons learned from GEOTRACES. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2016; 374:20160076. [PMID: 29035267 PMCID: PMC5069537 DOI: 10.1098/rsta.2016.0076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 06/30/2016] [Indexed: 05/06/2023]
Abstract
Continental shelves and shelf seas play a central role in the global carbon cycle. However, their importance with respect to trace element and isotope (TEI) inputs to ocean basins is less well understood. Here, we present major findings on shelf TEI biogeochemistry from the GEOTRACES programme as well as a proof of concept for a new method to estimate shelf TEI fluxes. The case studies focus on advances in our understanding of TEI cycling in the Arctic, transformations within a major river estuary (Amazon), shelf sediment micronutrient fluxes and basin-scale estimates of submarine groundwater discharge. The proposed shelf flux tracer is 228-radium (T1/2 = 5.75 yr), which is continuously supplied to the shelf from coastal aquifers, sediment porewater exchange and rivers. Model-derived shelf 228Ra fluxes are combined with TEI/ 228Ra ratios to quantify ocean TEI fluxes from the western North Atlantic margin. The results from this new approach agree well with previous estimates for shelf Co, Fe, Mn and Zn inputs and exceed published estimates of atmospheric deposition by factors of approximately 3-23. Lastly, recommendations are made for additional GEOTRACES process studies and coastal margin-focused section cruises that will help refine the model and provide better insight on the mechanisms driving shelf-derived TEI fluxes to the ocean.This article is part of the themed issue 'Biological and climatic impacts of ocean trace element chemistry'.
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Affiliation(s)
- Matthew A Charette
- Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA
| | - Phoebe J Lam
- Department of Ocean Sciences, University of California-Santa Cruz, Santa Cruz, CA 95064, USA
| | - Maeve C Lohan
- Ocean and Earth Science, National Oceanography Centre, University of Southampton, Southampton SO14 3ZH, UK
| | - Eun Young Kwon
- Research Institute of Oceanography, Seoul National University, Seoul 151-742, Korea
| | - Vanessa Hatje
- Centro Interdisciplinar de Energia e Ambiente, Inst. de Química, Universidade Federal da Bahia, Salvador 40170-115, Brazil
| | - Catherine Jeandel
- University of Toulouse/CNRS/UPS/IRD/CNES, Observatoire Midi-Pyrénées, Toulouse 31400, France
| | - Alan M Shiller
- Department of Marine Science, University of Southern Mississippi, Stennis Space Center, MS 39529, USA
| | - Gregory A Cutter
- Department of Ocean, Earth, and Atmospheric Sciences, Old Dominion University, Norfolk, VA 23529, USA
| | - Alex Thomas
- School of GeoSciences, University of Edinburgh, Edinburgh EH9 3FE, UK
| | - Philip W Boyd
- Institute of Marine and Antarctic Studies, University of Tasmania, Hobart, Tasmania 7005, Australia
| | - William B Homoky
- Department of Earth Sciences, University of Oxford, Oxford OX1 3AN, UK
| | - Angela Milne
- School of Geography, Earth and Environmental Sciences, Plymouth University, Plymouth PL4 8AA, UK
| | - Helmuth Thomas
- Department of Oceanography, Dalhousie University, Halifax, Nova Scotia, Canada B3H 4R2
| | - Per S Andersson
- Department of Geosciences, Swedish Museum of Natural History, Stockholm 104 05, Sweden
| | - Don Porcelli
- Department of Earth Sciences, University of Oxford, Oxford OX1 3AN, UK
| | - Takahiro Tanaka
- Atmosphere and Ocean Research Institute, University of Tokyo, Kashiwanoha 5-1-5, Kashiwa Chiba 277-8564, Japan
| | - Walter Geibert
- Marine Geochemistry Department, Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany
| | - Frank Dehairs
- Earth System Sciences and Analytical, Environmental and Geo-Chemistry, Vrije Universiteit Brussel, Brussels 1050, Belgium
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Ratnarajah L, Bowie AR. Nutrient Cycling: Are Antarctic Krill a Previously Overlooked Source in the Marine Iron Cycle? Curr Biol 2016; 26:R884-R887. [PMID: 27728790 DOI: 10.1016/j.cub.2016.08.044] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Iron limits phytoplankton growth in large areas of the Southern Ocean. A new study shows that Antarctic krill play a crucial role in the recycling of iron in the iron-limited waters.
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Affiliation(s)
- Lavenia Ratnarajah
- Institute for Marine and Antarctic Studies, University of Tasmania, Private Bag 129, Hobart, Tasmania 7001, Australia; Antarctic Climate and Ecosystems Cooperative Research Centre, University of Tasmania, Private Bag 80, Hobart, Tasmania 7001, Australia
| | - Andrew R Bowie
- Institute for Marine and Antarctic Studies, University of Tasmania, Private Bag 129, Hobart, Tasmania 7001, Australia; Antarctic Climate and Ecosystems Cooperative Research Centre, University of Tasmania, Private Bag 80, Hobart, Tasmania 7001, Australia.
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Conway TM, Hoffmann LJ, Breitbarth E, Strzepek RF, Wolff EW. The Growth Response of Two Diatom Species to Atmospheric Dust from the Last Glacial Maximum. PLoS One 2016; 11:e0158553. [PMID: 27384948 PMCID: PMC4934930 DOI: 10.1371/journal.pone.0158553] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Accepted: 06/19/2016] [Indexed: 11/19/2022] Open
Abstract
Relief of iron (Fe) limitation in the surface Southern Ocean has been suggested as one driver of the regular glacial-interglacial cycles in atmospheric carbon dioxide (CO2). The proposed cause is enhanced deposition of Fe-bearing atmospheric dust to the oceans during glacial intervals, with consequent effects on export production and the carbon cycle. However, understanding the role of enhanced atmospheric Fe supply in biogeochemical cycles is limited by knowledge of the fluxes and ‘bioavailability’ of atmospheric Fe during glacial intervals. Here, we assess the effect of Fe fertilization by dust, dry-extracted from the Last Glacial Maximum portion of the EPICA Dome C Antarctic ice core, on the Antarctic diatom species Eucampia antarctica and Proboscia inermis. Both species showed strong but differing reactions to dust addition. E. antarctica increased cell number (3880 vs. 786 cells mL-1), chlorophyll a (51 vs. 3.9 μg mL-1) and particulate organic carbon (POC; 1.68 vs. 0.28 μg mL-1) production in response to dust compared to controls. P. inermis did not increase cell number in response to dust, but chlorophyll a and POC per cell both strongly increased compared to controls (39 vs. 15 and 2.13 vs. 0.95 ng cell-1 respectively). The net result of both responses was a greater production of POC and chlorophyll a, as well as decreased Si:C and Si:N incorporation ratios within cells. However, E, antarctica decreased silicate uptake for the same nitrate and carbon uptake, while P. inermis increased carbon and nitrate uptake for the same silicate uptake. This suggests that nutrient utilization changes in response to Fe addition could be driven by different underlying mechanisms between different diatom species. Enhanced supply of atmospheric dust to the surface ocean during glacial intervals could therefore have driven nutrient-utilization changes which could permit greater carbon fixation for lower silica utilization. Additionally, both species responded more strongly to lower amounts of direct Fe chloride addition than they did to dust, suggesting that not all the Fe released from dust was in a bioavailable form available for uptake by diatoms.
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Affiliation(s)
- Tim M. Conway
- British Antarctic Survey, Cambridge, United Kingdom
- Department of Earth Sciences, University of Cambridge, Cambridge, United Kingdom
- Department of Earth Sciences, ETH Zürich, Zürich, Switzerland
- * E-mail:
| | - Linn J. Hoffmann
- Department of Chemistry, University of Otago, Dunedin, New Zealand
| | - Eike Breitbarth
- Department of Chemistry, University of Otago, Dunedin, New Zealand
| | | | - Eric W. Wolff
- British Antarctic Survey, Cambridge, United Kingdom
- Department of Earth Sciences, University of Cambridge, Cambridge, United Kingdom
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NATSUIKE M, KIKUCHI T, LEE YP, ITO H, FUJII M, YOSHIMURA C, WATANABE T. Chemical Speciation and Bioavailability of Iron in Natural Waters - Linkage of Forest, River and Sea in View of Dynamics of Iron and Organic Matter. ACTA ACUST UNITED AC 2016. [DOI: 10.2965/jswe.39.197] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Affiliation(s)
| | - Tetsuro KIKUCHI
- School of Environment and Society, Tokyo Institute of Technology
- Ibaraki Kasumigaura Environmental Science Center
| | - Ying Ping LEE
- School of Environment and Society, Tokyo Institute of Technology
| | - Hiroaki ITO
- Graduate School of Science and Technology, Kumamoto University
- Faculty of Agriculture, Yamagata University
| | - Manabu FUJII
- School of Environment and Society, Tokyo Institute of Technology
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Landa M, Blain S, Christaki U, Monchy S, Obernosterer I. Shifts in bacterial community composition associated with increased carbon cycling in a mosaic of phytoplankton blooms. ISME JOURNAL 2015. [PMID: 26196334 DOI: 10.1038/ismej.2015.105] [Citation(s) in RCA: 79] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Marine microbes have a pivotal role in the marine biogeochemical cycle of carbon, because they regulate the turnover of dissolved organic matter (DOM), one of the largest carbon reservoirs on Earth. Microbial communities and DOM are both highly diverse components of the ocean system, yet the role of microbial diversity for carbon processing remains thus far poorly understood. We report here results from an exploration of a mosaic of phytoplankton blooms induced by large-scale natural iron fertilization in the Southern Ocean. We show that in this unique ecosystem where concentrations of DOM are lowest in the global ocean, a patchwork of blooms is associated with diverse and distinct bacterial communities. By using on-board continuous cultures, we identify preferences in the degradation of DOM of different reactivity for taxa associated with contrasting blooms. We used the spatial and temporal variability provided by this natural laboratory to demonstrate that the magnitude of bacterial production is linked to the extent of compositional changes. Our results suggest that partitioning of the DOM resource could be a mechanism that structures bacterial communities with a positive feedback on carbon cycling. Our study, focused on bacterial carbon processing, highlights the potential role of diversity as a driving force for the cycling of biogeochemical elements.
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Affiliation(s)
- Marine Landa
- CNRS, Sorbonne Universités, UPMC Univ Paris 06, Laboratoire d'Océanographie Microbienne (LOMIC), Observatoire Océanologique, Banyuls/mer, Paris, France
| | - Stéphane Blain
- CNRS, Sorbonne Universités, UPMC Univ Paris 06, Laboratoire d'Océanographie Microbienne (LOMIC), Observatoire Océanologique, Banyuls/mer, Paris, France
| | - Urania Christaki
- INSU-CNRS, UMR 8187 LOG, Laboratoire d'Océanologie et de Géosciences, Université du Littoral Côte d'Opale, ULCO, Wimereux, France
| | - Sébastien Monchy
- INSU-CNRS, UMR 8187 LOG, Laboratoire d'Océanologie et de Géosciences, Université du Littoral Côte d'Opale, ULCO, Wimereux, France
| | - Ingrid Obernosterer
- CNRS, Sorbonne Universités, UPMC Univ Paris 06, Laboratoire d'Océanographie Microbienne (LOMIC), Observatoire Océanologique, Banyuls/mer, Paris, France
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Christaki U, Georges C, Genitsaris S, Monchy S. Microzooplankton community associated with phytoplankton blooms in the naturally iron-fertilized Kerguelen area (Southern Ocean). FEMS Microbiol Ecol 2015; 91:fiv068. [DOI: 10.1093/femsec/fiv068] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/14/2015] [Indexed: 01/07/2023] Open
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Gutt J, Bertler N, Bracegirdle TJ, Buschmann A, Comiso J, Hosie G, Isla E, Schloss IR, Smith CR, Tournadre J, Xavier JC. The Southern Ocean ecosystem under multiple climate change stresses--an integrated circumpolar assessment. GLOBAL CHANGE BIOLOGY 2015; 21:1434-53. [PMID: 25369312 DOI: 10.1111/gcb.12794] [Citation(s) in RCA: 77] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Accepted: 10/13/2014] [Indexed: 05/26/2023]
Abstract
A quantitative assessment of observed and projected environmental changes in the Southern Ocean (SO) with a potential impact on the marine ecosystem shows: (i) large proportions of the SO are and will be affected by one or more climate change processes; areas projected to be affected in the future are larger than areas that are already under environmental stress, (ii) areas affected by changes in sea-ice in the past and likely in the future are much larger than areas affected by ocean warming. The smallest areas (<1% area of the SO) are affected by glacier retreat and warming in the deeper euphotic layer. In the future, decrease in the sea-ice is expected to be widespread. Changes in iceberg impact resulting from further collapse of ice-shelves can potentially affect large parts of shelf and ephemerally in the off-shore regions. However, aragonite undersaturation (acidification) might become one of the biggest problems for the Antarctic marine ecosystem by affecting almost the entire SO. Direct and indirect impacts of various environmental changes to the three major habitats, sea-ice, pelagic and benthos and their biota are complex. The areas affected by environmental stressors range from 33% of the SO for a single stressor, 11% for two and 2% for three, to <1% for four and five overlapping factors. In the future, areas expected to be affected by 2 and 3 overlapping factors are equally large, including potential iceberg changes, and together cover almost 86% of the SO ecosystem.
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Affiliation(s)
- Julian Gutt
- Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Am Alten Hafen 26, Bremerhaven, D - 27568, Germany
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Luan F, Liu Y, Griffin AM, Gorski CA, Burgos WD. Iron(III)-bearing clay minerals enhance bioreduction of nitrobenzene by Shewanella putrefaciens CN32. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:1418-1426. [PMID: 25565314 DOI: 10.1021/es504149y] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Iron-bearing clay minerals are ubiquitous in the environment, and the clay-Fe(II)/Fe(III) redox couple plays important roles in abiotic reduction of several classes of environmental contaminants. We investigated the role of Fe-bearing clay minerals on the bioreduction of nitrobenzene. In experiments with Shewanella putrefaciens CN32 and excess electron donor, we found that the Fe-bearing clay minerals montmorillonite SWy-2 and nontronite NAu-2 enhanced nitrobenzene bioreduction. On short time scales (<50 h), nitrobenzene reduction was primarily biologically driven, but at later time points, nitrobenzene reduction by biologically formed structural Fe(II) in the clay minerals became increasingly important. We found that chemically reduced (dithionite) iron-bearing clay minerals reduced nitrobenzene more rapidly than biologically reduced iron-bearing clay minerals despite the minerals having similar structural Fe(II) concentrations. We also found that chemically reduced NAu-2 reduced nitrobenzene faster as compared to chemically reduced SWy-2. The different reactivity of SWy-2 versus NAu-2 toward nitrobenzene was caused by different forms of structural clay-Fe(II) in the clay minerals and different reduction potentials (Eh) of the clay minerals. Because most contaminated aquifers become reduced via biological activity, the reactivity of biogenic clay-Fe(II) toward reducible contaminants is particularly important.
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Affiliation(s)
- Fubo Luan
- Department of Civil and Environmental Engineering, The Pennsylvania State University , University Park, Pennsylvania 16801-1408, United States
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Xiao X, Sogge H, Lagesen K, Tooming-Klunderud A, Jakobsen KS, Rohrlack T. Use of high throughput sequencing and light microscopy show contrasting results in a study of phytoplankton occurrence in a freshwater environment. PLoS One 2014; 9:e106510. [PMID: 25171164 PMCID: PMC4149573 DOI: 10.1371/journal.pone.0106510] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Accepted: 07/19/2014] [Indexed: 11/25/2022] Open
Abstract
Assessing phytoplankton diversity is of primary importance for both basic and applied ecological studies. Following the advances in molecular methods, phytoplankton studies are switching from using classical microscopy to high throughput sequencing approaches. However, methodological comparisons of these approaches have rarely been reported. In this study, we compared the two methods, using a unique dataset of multiple water samples taken from a natural freshwater environment. Environmental DNA was extracted from 300 water samples collected weekly during 20 years, followed by high throughput sequencing of amplicons from the 16S and 18S rRNA hypervariable regions. For each water sample, phytoplankton diversity was also estimated using light microscopy. Our study indicates that species compositions detected by light microscopy and 454 high throughput sequencing do not always match. High throughput sequencing detected more rare species and picoplankton than light microscopy, and thus gave a better assessment of phytoplankton diversity. However, when compared to light microscopy, high throughput sequencing of 16S and 18S rRNA amplicons did not adequately identify phytoplankton at the species level. In summary, our study recommends a combined strategy using both morphological and molecular techniques.
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Affiliation(s)
- Xi Xiao
- University of Oslo, Centre for Ecological and Evolutionary Synthesis (CEES), Department of Biosciences, Oslo, Norway
- Zhejiang University, Ocean College, Hangzhou, China
| | - Hanne Sogge
- University of Oslo, Centre for Ecological and Evolutionary Synthesis (CEES), Department of Biosciences, Oslo, Norway
| | - Karin Lagesen
- University of Oslo, Centre for Ecological and Evolutionary Synthesis (CEES), Department of Biosciences, Oslo, Norway
- Norwegian Sequencing Centre, Department of Medical Genetics, Oslo University Hospital, Oslo, Norway
| | - Ave Tooming-Klunderud
- University of Oslo, Centre for Ecological and Evolutionary Synthesis (CEES), Department of Biosciences, Oslo, Norway
| | - Kjetill S. Jakobsen
- University of Oslo, Centre for Ecological and Evolutionary Synthesis (CEES), Department of Biosciences, Oslo, Norway
| | - Thomas Rohrlack
- Norwegian University of Life Sciences, Department of Plant and Environmental Sciences, Ås, Norway
- Norwegian Institute for Water Research (NIVA), Oslo, Norway
- * E-mail:
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Distinct iron isotopic signatures and supply from marine sediment dissolution. Nat Commun 2014; 4:2143. [PMID: 23868399 PMCID: PMC3759054 DOI: 10.1038/ncomms3143] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2013] [Accepted: 06/11/2013] [Indexed: 11/16/2022] Open
Abstract
Oceanic iron inputs must be traced and quantified to learn how they affect primary productivity and climate. Chemical reduction of iron in continental margin sediments provides a substantial dissolved flux to the oceans, which is isotopically lighter than the crust, and so may be distinguished in seawater from other sources, such as wind-blown dust. However, heavy iron isotopes measured in seawater have recently led to the proposition of another source of dissolved iron from ‘non-reductive’ dissolution of continental margins. Here we present the first pore water iron isotope data from a passive-tectonic and semi-arid ocean margin (South Africa), which reveals a smaller and isotopically heavier flux of dissolved iron to seawater than active-tectonic and dysoxic continental margins. These data provide in situ evidence of non-reductive iron dissolution from a continental margin, and further show that geological and hydro-climatic factors may affect the amount and isotopic composition of iron entering the ocean. The dissolution of iron from sediments along ocean margins may stimulate photosynthesis and moderate global climate. This study shows how margin sediments supply iron in varying amounts between regions, and by distinct mechanisms, which may be due to geological characteristics and hydrological controls on land.
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Thick-shelled, grazer-protected diatoms decouple ocean carbon and silicon cycles in the iron-limited Antarctic Circumpolar Current. Proc Natl Acad Sci U S A 2013; 110:20633-8. [PMID: 24248337 DOI: 10.1073/pnas.1309345110] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Diatoms of the iron-replete continental margins and North Atlantic are key exporters of organic carbon. In contrast, diatoms of the iron-limited Antarctic Circumpolar Current sequester silicon, but comparatively little carbon, in the underlying deep ocean and sediments. Because the Southern Ocean is the major hub of oceanic nutrient distribution, selective silicon sequestration there limits diatom blooms elsewhere and consequently the biotic carbon sequestration potential of the entire ocean. We investigated this paradox in an in situ iron fertilization experiment by comparing accumulation and sinking of diatom populations inside and outside the iron-fertilized patch over 5 wk. A bloom comprising various thin- and thick-shelled diatom species developed inside the patch despite the presence of large grazer populations. After the third week, most of the thinner-shelled diatom species underwent mass mortality, formed large, mucous aggregates, and sank out en masse (carbon sinkers). In contrast, thicker-shelled species, in particular Fragilariopsis kerguelensis, persisted in the surface layers, sank mainly empty shells continuously, and reduced silicate concentrations to similar levels both inside and outside the patch (silica sinkers). These patterns imply that thick-shelled, hence grazer-protected, diatom species evolved in response to heavy copepod grazing pressure in the presence of an abundant silicate supply. The ecology of these silica-sinking species decouples silicon and carbon cycles in the iron-limited Southern Ocean, whereas carbon-sinking species, when stimulated by iron fertilization, export more carbon per silicon. Our results suggest that large-scale iron fertilization of the silicate-rich Southern Ocean will not change silicon sequestration but will add carbon to the sinking silica flux.
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Response of phytoplankton photophysiology to varying environmental conditions in the Sub-Antarctic and Polar Frontal Zone. PLoS One 2013; 8:e72165. [PMID: 23977242 PMCID: PMC3747055 DOI: 10.1371/journal.pone.0072165] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2012] [Accepted: 07/12/2013] [Indexed: 11/19/2022] Open
Abstract
Climate-driven changes are expected to alter the hydrography of the Sub-Antarctic Zone (SAZ) and Polar Frontal Zone (PFZ) south of Australia, in which distinct regional environments are believed to be responsible for the differences in phytoplankton biomass in these regions. Here, we report how the dynamic influences of light, iron and temperature, which are responsible for the photophysiological differences between phytoplankton in the SAZ and PFZ, contribute to the biomass differences in these regions. High effective photochemical efficiency of photosystem II (F'(q)/F'(m)0.4), maximum photosynthesis rate (P(B)(max)), light-saturation intensity (E(k)), maximum rate of photosynthetic electron transport (1/[Symbol: see text]PSII), and low photoprotective pigment concentrations observed in the SAZ correspond to high chlorophyll a and iron concentrations. In contrast, phytoplankton in the PFZ exhibits low F'(q)/F'(M) (~ 0.2) and high concentrations of photoprotective pigments under low light environment. Strong negative relationships between iron, temperature, and photoprotective pigments demonstrate that cells were producing more photoprotective pigments under low temperature and iron conditions, and are responsible for the low biomass and low productivity measured in the PFZ. As warming and enhanced iron input is expected in this region, this could probably increase phytoplankton photosynthesis in this region. However, complex interactions between the biogeochemical processes (e.g. stratification caused by warming could prevent mixing of nutrients), which control phytoplankton biomass and productivity, remain uncertain.
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Prince EK, Irmer F, Pohnert G. Domoic acid improves the competitive ability of Pseudo-nitzschia delicatissima against the diatom Skeletonema marinoi. Mar Drugs 2013; 11:2398-412. [PMID: 23852091 PMCID: PMC3736430 DOI: 10.3390/md11072398] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2013] [Revised: 06/19/2013] [Accepted: 06/28/2013] [Indexed: 11/16/2022] Open
Abstract
Because domoic acid, a neurotoxic secondary metabolite produced by marine diatoms in the genus Pseudo-nitzschia, is hypothesized to be part of a high affinity iron uptake system, we investigated whether domoic acid could improve the competitive ability of Pseudo-nitzschia delicatissima, and whether the availability of iron changed the outcome of competition experiments. We found that domoic acid had a slight negative effect on growth of the diatom Skeletonema marinoi when it was grown in monocultures. However, when S. marinoi was cultured with P. delicatissima the presence of domoic acid resulted in a reduction of S. marinoi cells by up to 38% and an increase in P. delicatissima cell numbers by up to 17% under iron replete conditions. Similar effects were not observed in low iron treatments. Domoic acid was not taken up by P. delicatissima cells. Overall, our results indicate that domoic acid can improve the competitive ability of Pseudo-nitzschia spp. and that iron is likely to be involved. This study provides an unusual example of indirect inhibition of competitor growth mediated by a secondary metabolite.
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Affiliation(s)
- Emily K. Prince
- Department of Mathematics, Sciences, and Technology, Paine College, 1235 15th Street, Augusta, GA 30901, USA
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +1-706-896-8108
| | - Friederike Irmer
- Institute for Inorganic and Analytical Chemistry, Friedrich Schiller University, Lessingstrasse 8, Jena 07743, Germany; E-Mails: (F.I.); (G.P.)
| | - Georg Pohnert
- Institute for Inorganic and Analytical Chemistry, Friedrich Schiller University, Lessingstrasse 8, Jena 07743, Germany; E-Mails: (F.I.); (G.P.)
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Dold B, Gonzalez-Toril E, Aguilera A, Lopez-Pamo E, Cisternas ME, Bucchi F, Amils R. Acid rock drainage and rock weathering in Antarctica: important sources for iron cycling in the Southern Ocean. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2013; 47:6129-36. [PMID: 23682976 DOI: 10.1021/es305141b] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Here we describe biogeochemical processes that lead to the generation of acid rock drainage (ARD) and rock weathering on the Antarctic landmass and describe why they are important sources of iron into the Antarctic Ocean. During three expeditions, 2009-2011, we examined three sites on the South Shetland Islands in Antarctica. Two of them displayed intensive sulfide mineralization and generated acidic (pH 3.2-4.5), iron-rich drainage waters (up to 1.78 mM Fe), which infiltrated as groundwater (as Fe(2+)) and as superficial runoff (as Fe(3+)) into the sea, the latter with the formation of schwertmannite in the sea-ice. The formation of ARD in the Antarctic was catalyzed by acid mine drainage microorganisms found in cold climates, including Acidithiobacillus ferrivorans and Thiobacillus plumbophilus. The dissolved iron (DFe) flux from rock weathering (nonmineralized control site) was calculated to be 0.45 × 10(9) g DFe yr(-1) for the nowadays 5468 km of ice-free Antarctic rock coastline which is of the same order of magnitude as glacial or aeolian input to the Southern Ocean. Additionally, the two ARD sites alone liberate 0.026 and 0.057 × 10(9) g DFe yr(-1) as point sources to the sea. The increased iron input correlates with increased phytoplankton production close to the source. This might even be enhanced in the future by a global warming scenario, and could be a process counterbalancing global warming.
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Affiliation(s)
- B Dold
- Instituto de Geología Económica Aplicada, Universidad de Concepción, Concepción, Chile
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Priede IG, Bergstad OA, Miller PI, Vecchione M, Gebruk A, Falkenhaug T, Billett DSM, Craig J, Dale AC, Shields MA, Tilstone GH, Sutton TT, Gooday AJ, Inall ME, Jones DOB, Martinez-Vicente V, Menezes GM, Niedzielski T, Sigurðsson Þ, Rothe N, Rogacheva A, Alt CHS, Brand T, Abell R, Brierley AS, Cousins NJ, Crockard D, Hoelzel AR, Høines Å, Letessier TB, Read JF, Shimmield T, Cox MJ, Galbraith JK, Gordon JDM, Horton T, Neat F, Lorance P. Does presence of a mid-ocean ridge enhance biomass and biodiversity? PLoS One 2013; 8:e61550. [PMID: 23658696 PMCID: PMC3642170 DOI: 10.1371/journal.pone.0061550] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2012] [Accepted: 03/11/2013] [Indexed: 11/19/2022] Open
Abstract
In contrast to generally sparse biological communities in open-ocean settings, seamounts and ridges are perceived as areas of elevated productivity and biodiversity capable of supporting commercial fisheries. We investigated the origin of this apparent biological enhancement over a segment of the North Mid-Atlantic Ridge (MAR) using sonar, corers, trawls, traps, and a remotely operated vehicle to survey habitat, biomass, and biodiversity. Satellite remote sensing provided information on flow patterns, thermal fronts, and primary production, while sediment traps measured export flux during 2007-2010. The MAR, 3,704,404 km(2) in area, accounts for 44.7% lower bathyal habitat (800-3500 m depth) in the North Atlantic and is dominated by fine soft sediment substrate (95% of area) on a series of flat terraces with intervening slopes either side of the ridge axis contributing to habitat heterogeneity. The MAR fauna comprises mainly species known from continental margins with no evidence of greater biodiversity. Primary production and export flux over the MAR were not enhanced compared with a nearby reference station over the Porcupine Abyssal Plain. Biomasses of benthic macrofauna and megafauna were similar to global averages at the same depths totalling an estimated 258.9 kt C over the entire lower bathyal north MAR. A hypothetical flat plain at 3500 m depth in place of the MAR would contain 85.6 kt C, implying an increase of 173.3 kt C attributable to the presence of the Ridge. This is approximately equal to 167 kt C of estimated pelagic biomass displaced by the volume of the MAR. There is no enhancement of biological productivity over the MAR; oceanic bathypelagic species are replaced by benthic fauna otherwise unable to survive in the mid ocean. We propose that globally sea floor elevation has no effect on deep sea biomass; pelagic plus benthic biomass is constant within a given surface productivity regime.
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Affiliation(s)
- Imants G Priede
- Oceanlab, Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, United Kingdom.
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