1
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Zehr JP, Capone DG. Unsolved mysteries in marine nitrogen fixation. Trends Microbiol 2024; 32:532-545. [PMID: 37658011 DOI: 10.1016/j.tim.2023.08.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2023] [Revised: 08/03/2023] [Accepted: 08/04/2023] [Indexed: 09/03/2023]
Abstract
Biological nitrogen (N2) fixation is critical in global biogeochemical cycles and in sustaining the productivity of the oceans. There remain many unanswered questions, unresolved hypotheses, and unchallenged paradigms. The fundamental balance of N input and losses has not been fully resolved. One of the major N2-fixers, Trichodesmium, remains an enigma with intriguing biological and ecological secrets. Cyanobacterial N2 fixation, once thought to be primarily due to free-living cyanobacteria, now also appears to be dependent on microbial interactions, from microbiomes to unicellular symbioses, which remain poorly characterized. Nitrogenase genes associated with diverse non-cyanobacterial diazotrophs (NCDs) are prevalent, but their significance remains a huge knowledge gap. Answering questions, new and old, such as those discussed here, is needed to understand the ocean's N and C cycles and their responses to environmental change.
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Affiliation(s)
- Jonathan P Zehr
- Ocean Sciences Department, University of California Santa Cruz, Santa Cruz, CA, USA.
| | - Douglas G Capone
- Marine and Environmental Biology Section of Biological Sciences, University of Southern California, Los Angeles, CA, USA
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2
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Wang T, Gao M, Shao W, Wang L, Yang C, Wang X, Yao S, Zhang B. Dissecting the role of soybean rhizosphere-enriched bacterial taxa in modulating nitrogen-cycling functions. Appl Microbiol Biotechnol 2024; 108:347. [PMID: 38805033 PMCID: PMC11133221 DOI: 10.1007/s00253-024-13184-5] [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: 12/28/2023] [Revised: 04/30/2024] [Accepted: 05/15/2024] [Indexed: 05/29/2024]
Abstract
Crop roots selectively recruit certain microbial taxa that are essential for supporting their growth. Within the recruited microbes, some taxa are consistently enriched in the rhizosphere across various locations and crop genotypes, while others are unique to specific planting sites or genotypes. Whether these differentially enriched taxa are different in community composition and how they interact with nutrient cycling need further investigation. Here, we sampled bulk soil and the rhizosphere soil of five soybean varieties grown in Shijiazhuang and Xuzhou, categorized the rhizosphere-enriched microbes into shared, site-specific, and variety-specific taxa, and analyzed their correlation with the diazotrophic communities and microbial genes involved in nitrogen (N) cycling. The shared taxa were dominated by Actinobacteria and Thaumarchaeota, the site-specific taxa were dominated by Actinobacteria in Shijiazhuang and by Nitrospirae in Xuzhou, while the variety-specific taxa were more evenly distributed in several phyla and contained many rare operational taxonomic units (OTUs). The rhizosphere-enriched taxa correlated with most diazotroph orders negatively but with eight orders including Rhizobiales positively. Each group within the shared, site-specific, and variety-specific taxa negatively correlated with bacterial amoA and narG in Shijiazhuang and positively correlated with archaeal amoA in Xuzhou. These results revealed that the shared, site-specific, and variety-specific taxa are distinct in community compositions but similar in associations with rhizosphere N-cycling functions. They exhibited potential in regulating the soybean roots' selection for high-efficiency diazotrophs and the ammonia-oxidizing and denitrification processes. This study provides new insights into soybean rhizosphere-enriched microbes and their association with N cycling. KEY POINTS: • Soybean rhizosphere affected diazotroph community and enriched nifH, amoA, and nosZ. • Shared and site- and variety-specific taxa were dominated by different phyla. • Rhizosphere-enriched taxa were similarly associated with N-cycle functions.
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Affiliation(s)
- Tianshu Wang
- State Key Laboratory of Efficient Utilization of Arid and Semi-Arid Arable Land in Northern China, The Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Miao Gao
- State Key Laboratory of Efficient Utilization of Arid and Semi-Arid Arable Land in Northern China, The Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Weiwei Shao
- State Key Laboratory of Efficient Utilization of Arid and Semi-Arid Arable Land in Northern China, The Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Li Wang
- State Key Laboratory of Efficient Utilization of Arid and Semi-Arid Arable Land in Northern China, The Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Chunyan Yang
- The Key Laboratory of Crop Genetics and Breeding of Hebei, Institute of Cereal and Oil Crops, Hebei Academy of Agricultural and Forestry Sciences, Shijiazhuang, 050031, China
| | - Xing Wang
- Jiangsu Xuhuai Regional Institute of Agricultural Sciences, Xuzhou, 221131, China
| | - Shuihong Yao
- State Key Laboratory of Efficient Utilization of Arid and Semi-Arid Arable Land in Northern China, The Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
| | - Bin Zhang
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China.
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3
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Siriwardana H, Samarasekara RSM, Anthony D, Vithanage M. Measurements and analysis of nitrogen and phosphorus in oceans: Practice, frontiers, and insights. Heliyon 2024; 10:e28182. [PMID: 38560146 PMCID: PMC10979167 DOI: 10.1016/j.heliyon.2024.e28182] [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: 07/05/2023] [Revised: 03/11/2024] [Accepted: 03/13/2024] [Indexed: 04/04/2024] Open
Abstract
Nitrogen and phosphorus concentrations in oceans have been extensively studied, and advancements in associated disciplines have rapidly progressed, enabling the exploration of novel and previously challenging questions. A keyword analysis was conducted using the Scopus database to examine chronological trends and hotspots, offering comprehensive insights into the evolution of marine nitrogen and phosphorus research. For this purpose, author keyword networks were developed for the periods before 1990, 1990 to 2000, 2001 to 2011, and 2012 to 2022. Furthermore, analytical techniques employed in the recent decade to determine nitrogen and phosphorus concentrations in seawater were assessed for their applicability and limitations through a critical review of more than 50 journal articles. Taxonomy and nitrogen biogeochemistry were the prominent research interests for the first two periods, respectively, while stable isotopic tracking of nitrogen and phosphorus processes emerged as the dominant research focus for the last two decades. The integration of macroeconomic factors in research development and the chronological rise of interdisciplinary research were identified. Conventional analytical techniques such as spectrophotometry, colorimetry, fluorometry, and elemental analysis were noted, along with emerging techniques like remote sensing and microfluidic sensors.
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Affiliation(s)
- Hasitha Siriwardana
- Faculty of Engineering, University of Sri Jayewardenepura, 41, Lumbini Avenue, Ratmalana 10390, Sri Lanka
| | - R S M Samarasekara
- Faculty of Engineering, University of Sri Jayewardenepura, 41, Lumbini Avenue, Ratmalana 10390, Sri Lanka
| | - Damsara Anthony
- Faculty of Engineering, University of Sri Jayewardenepura, 41, Lumbini Avenue, Ratmalana 10390, Sri Lanka
- Department of Civil Engineering, Faculty of Engineering, General Sir John Kotelawala Defence University, Ratmalana, Sri Lanka
| | - Meththika Vithanage
- Ecosphere Resilience Research Center (ERRC), Faculty of Applied Sciences, University of Sri Jayewardenepura, Nugegoda 10250, Sri Lanka
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4
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Gao W, Zhao J, Guo X, Wang F, Chen X, Zhu Z, Ge T, Wang L, Kuzyakov Y, Wu J, Jia Z. Intensive N 2 fixation accelerates microbial turnover in cropland soils. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 916:170081. [PMID: 38220009 DOI: 10.1016/j.scitotenv.2024.170081] [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: 11/23/2023] [Revised: 01/08/2024] [Accepted: 01/08/2024] [Indexed: 01/16/2024]
Abstract
Biological nitrogen fixation (BNF) is strongly affected by the carbon (C) and nitrogen (N) stoichiometry in soil and depends on the input of organic C. Due to the high metabolic costs of nitrogenase activity, however, the response of BNF to organic C input and its impact on microbial turnover remain unclear. To address this knowledge gap, we combined 15N2 tracing with high-throughput sequencing by adding glucose or glucose plus mineral N fertilizer for a 12-day incubation in three cropland soils. Glucose addition alone strongly changed the BNF activity (0.76-2.51 mg N kg-1 d-1), while BNF was completely absent after mineral N fertilization. This switch-on of BNF by glucose addition supported equally high rates of microbial growth and organic C mineralization compared with the direct mineral N assimilation by microorganisms. Glucose-induced BNF was predominantly catalyzed by Azotobacter-affiliated free-living diazotrophs (>50 % of the total nifH genes), which increased with diverse nondiazotrophs such as Nitrososphaera, Bacillus and Pseudoxanthomonas. Structural equation models (SEMs) and random forest (RF) analyses consistently revealed that the soil C:N ratio and Azotobacter-affiliated diazotrophic abundances were the key factors affecting glucose-induced BNF. Our findings emphasize the importance of free-living diazotrophs for microbial turnover of organic C in soil.
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Affiliation(s)
- Wei Gao
- Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125, PR China; State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, PR China
| | - Jun Zhao
- Department of Microbiology & Cell Science, Fort Lauderdale Research and Education Center, Institute for Food and Agricultural Sciences (IFAS), University of Florida, Davie, FL 33314, USA
| | - Xiaobin Guo
- Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125, PR China
| | - Fang Wang
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, PR China
| | - Xiangbi Chen
- Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125, PR China
| | - Zhenke Zhu
- Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125, PR China; State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Institute of Plant Virology, Ningbo University, Ningbo 315211, PR China
| | - Tida Ge
- Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125, PR China; State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Institute of Plant Virology, Ningbo University, Ningbo 315211, PR China
| | - Lianfeng Wang
- College of Environmental and Chemical Engineering, Dalian Jiaotong University, Dalian 116028, PR China
| | - Yakov Kuzyakov
- Department of Soil Science of Temperate Ecosystems, Department of Agricultural Soil Science, University of Goettingen, Göttingen 37077, Germany; Peoples Friendship University of Russia (RUDN University), Moscow 117198, Russia; Institute of Environmental Sciences, Kazan Federal University, Kazan 420049, Russia
| | - Jinshui Wu
- Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125, PR China
| | - Zhongjun Jia
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, PR China; State Key Laboratory of Black Soils Conservation and Utilization, Northeast Institute of Geography and Agroecology, Chinese Academy of Science, Changchun 130102, PR China.
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Vieyra‐Mexicano C, Souza V, Pajares S. Distribution of the N 2 -fixing cyanobacterium Candidatus Atelocyanobacterium thalassa in the Mexican Pacific upwelling system under two contrasting El Niño Southern Oscillation conditions. ENVIRONMENTAL MICROBIOLOGY REPORTS 2024; 16:e13237. [PMID: 38350668 PMCID: PMC10866059 DOI: 10.1111/1758-2229.13237] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Accepted: 01/19/2024] [Indexed: 02/15/2024]
Abstract
The unicellular cyanobacterium Candidatus Atelocyanobacterium thalassa (UCYN-A) is a key diazotroph in the global ocean owing to its high N2 fixation rates and wide distribution in marine environments. Nevertheless, little is known about UCYN-A in oxygen-deficient zones (ODZs), which may be optimal environments for marine diazotrophy. Therefore, the distribution and diversity of UCYN-A were studied in two consecutive years under contrasting phases (La Niña vs. El Niño) of El Niño Southern Oscillation (ENSO) along a transect in the ODZ of the Mexican Pacific upwelling system. Of the three UCYN-A sublineages found, UCYN-A1 and UCYN-A3 were barely detected, whereas UCYN-A2 was dominant in all the stations and showed a wide distribution in both ENSO phases. The presence of UCYN-A was associated with well-oxygenated waters, but it was also found for the first time under suboxic conditions (<20 μM) at the bottom of a shallow coastal station, within the oxygen-poor and nutrient-rich Subsurface Subtropical water mass. This study contributes to the understanding of UCYN-A distribution under different oceanographic conditions associated with ENSO phases in upwelling systems, especially because of the current climate change and increasing deoxygenation in many areas of the world's oceans.
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Affiliation(s)
- Cinthya Vieyra‐Mexicano
- Unidad Académica de Ecología y Biodiversidad Acuática, Institute of Marine Sciences and LimnologyNational Autonomous University of MexicoMexico CityMexico
- Posgrado en Ciencias del Mar y LimnologíaNational Autonomous University of MexicoMexico CityMexico
| | - Valeria Souza
- Departamento de Ecología Evolutiva, Institute of EcologyNational Autonomous University of MexicoMexico CityMexico
| | - Silvia Pajares
- Unidad Académica de Ecología y Biodiversidad Acuática, Institute of Marine Sciences and LimnologyNational Autonomous University of MexicoMexico CityMexico
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Colussi A, Bokhari SNH, Mijovilovich A, Koník P, Küpper H. Acclimation to medium-level non-lethal iron limitation: Adjustment of electron flow around the PSII and metalloprotein expression in Trichodesmium erythraeum IMS101. BIOCHIMICA ET BIOPHYSICA ACTA. BIOENERGETICS 2024; 1865:149015. [PMID: 37742749 DOI: 10.1016/j.bbabio.2023.149015] [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: 03/17/2023] [Revised: 09/15/2023] [Accepted: 09/18/2023] [Indexed: 09/26/2023]
Abstract
The aim of this study was to investigate how acclimation to medium-level, long-term, non-lethal iron limitation changes the electron flux around the Photosystem II of the oceanic diazotroph Trichodesmium erythraeum IMS101. Fe availability of about 5× and 100× lower than a replete level, i.e. conditions common in the natural environment of this cyanobacterium, were applied in chemostats. The response of the cells was studied not only in terms of growth, but also mechanistically, measuring the chlorophyll fluorescence of dark-adapted filaments via imaging fluorescence kinetic microscopy (FKM) with 0.3 ms time resolution. Combining these measurements with those of metal binding to proteins via online coupling of metal-free HPLC (size exclusion chromatography SEC) to sector-field ICP-MS allowed to track the fate of the photosystems, together with other metalloproteins. General increase of fluorescence has been observed, with the consequent decrease in the quantum yields φ of the PSII, while the efficiency ψ of the electron flux between PSII and the PSI remained surprisingly unchanged. This indicates the ability of Trichodesmium to cope with a situation that makes assembling the many iron clusters in Photosystem I a particular challenge, as shown by decreasing ratios of Fe to Mg in these proteins. The negative effect of Fe limitation on PSII may also be due to its fast turnover. A broader view was obtained from metalloproteomics via HPLC-ICP-MS, revealing a differential protein expression pattern under iron limitation with a drastic down-regulation especially of iron-containing proteins and some increase in low MW metal-binding complexes.
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Affiliation(s)
- Antonio Colussi
- Czech Academy of Sciences, Biology Centre, Institute of Plant Molecular Biology, Laboratory of Plant Biophysics and Biochemistry, České Budějovice, Czech Republic; University of South Bohemia, Faculty of Sciences, Department of Experimental Plant Biology, České Budějovice, Czech Republic
| | - Syed Nadeem Hussain Bokhari
- Czech Academy of Sciences, Biology Centre, Institute of Plant Molecular Biology, Laboratory of Plant Biophysics and Biochemistry, České Budějovice, Czech Republic
| | - Ana Mijovilovich
- Czech Academy of Sciences, Biology Centre, Institute of Plant Molecular Biology, Laboratory of Plant Biophysics and Biochemistry, České Budějovice, Czech Republic
| | - Peter Koník
- University of South Bohemia, Faculty of Sciences, Department of Chemistry, České Budějovice, Czech Republic
| | - Hendrik Küpper
- Czech Academy of Sciences, Biology Centre, Institute of Plant Molecular Biology, Laboratory of Plant Biophysics and Biochemistry, České Budějovice, Czech Republic; University of South Bohemia, Faculty of Sciences, Department of Experimental Plant Biology, České Budějovice, Czech Republic.
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7
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Eichner M, Inomura K, Pierella Karlusich JJ, Shaked Y. Better together? Lessons on sociality from Trichodesmium. Trends Microbiol 2023; 31:1072-1084. [PMID: 37244772 DOI: 10.1016/j.tim.2023.05.001] [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: 12/27/2022] [Revised: 04/30/2023] [Accepted: 05/01/2023] [Indexed: 05/29/2023]
Abstract
The N2-fixing cyanobacterium Trichodesmium is an important player in the oceanic nitrogen and carbon cycles. Trichodesmium occurs both as single trichomes and as colonies containing hundreds of trichomes. In this review, we explore the benefits and disadvantages of colony formation, considering physical, chemical, and biological effects from nanometer to kilometer scale. Showing that all major life challenges are affected by colony formation, we claim that Trichodesmium's ecological success is tightly linked to its colonial lifestyle. Microbial interactions in the microbiome, chemical gradients within the colony, interactions with particles, and elevated mobility in the water column shape a highly dynamic microenvironment. We postulate that these dynamics are key to the resilience of Trichodesmium and other colony formers in our changing environment.
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Affiliation(s)
- Meri Eichner
- Centre Algatech, Institute of Microbiology of the Czech Academy of Sciences, Třeboň, Czech Republic.
| | - Keisuke Inomura
- Graduate School of Oceanography, University of Rhode Island, Narragansett, RI, USA
| | | | - Yeala Shaked
- Freddy and Nadine Herrmann Institute of Earth Sciences, Hebrew University, Jerusalem, Israel; Interuniversity Institute for Marine Sciences, Eilat, Israel
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8
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Robicheau BM, Tolman J, Desai D, LaRoche J. Microevolutionary patterns in ecotypes of the symbiotic cyanobacterium UCYN-A revealed from a Northwest Atlantic coastal time series. SCIENCE ADVANCES 2023; 9:eadh9768. [PMID: 37774025 PMCID: PMC10541017 DOI: 10.1126/sciadv.adh9768] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2023] [Accepted: 08/28/2023] [Indexed: 10/01/2023]
Abstract
UCYN-A is a globally important nitrogen-fixing symbiotic microbe often found in colder regions and coastal areas where nitrogen fixation has been overlooked. We present a 3-year coastal Northwest Atlantic time series of UCYN-A by integrating oceanographic data with weekly nifH and16S rRNA gene sequencing and quantitative PCR assays for UCYN-A ecotypes. High UCYN-A relative abundances dominated by A1 to A4 ecotypes reoccurred annually in the coastal Northwest Atlantic. Although UCYN-A was detected every summer/fall, the ability to observe separate ecotypes may be highly dependent on sampling time given intense interannual and weekly variability of ecotype-specific occurrences. Additionally, much of UCYN-A's rarer diversity was populated by short-lived neutral mutational variants, therefore providing insight into UCYN-A's microevolutionary patterns. For instance, rare ASVs exhibited community composition restructuring annually, while also sharing a common connection to a dominant ASV within each ecotype. Our study provides additional perspectives for interpreting UCYN-A intraspecific diversity and underscores the need for high-resolution datasets when deciphering spatiotemporal ecologies within UCYN-A.
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Affiliation(s)
- Brent M. Robicheau
- Department of Biology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Jennifer Tolman
- Department of Biology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Dhwani Desai
- Department of Biology, Dalhousie University, Halifax, Nova Scotia, Canada
- Integrated Microbiome Resource, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Julie LaRoche
- Department of Biology, Dalhousie University, Halifax, Nova Scotia, Canada
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9
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Kang W, Sun S, Hu X. Microplastics trigger the Matthew effect on nitrogen assimilation in marine diatoms at an environmentally relevant concentration. WATER RESEARCH 2023; 233:119762. [PMID: 36841163 DOI: 10.1016/j.watres.2023.119762] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 02/15/2023] [Accepted: 02/17/2023] [Indexed: 06/18/2023]
Abstract
Microplastics (MPs, diameter <5 mm) are widely distributed on Earth, especially in the oceans. Diatoms account for ∼40% of marine primary productivity and affect the global biogeochemical cycles of macroelements. However, the effects of MPs on marine nitrogen cycling remain poorly understood, particularly comparisons between nitrogen-replete and nitrogen-limited conditions. We found that MPs trigger the Matthew effect on nitrogen assimilation in diatoms, where MPs inhibited nitrogen assimilation under nitrogen-limited conditions while enhancing nitrogen metabolism under nitrogen-replete conditions in Phaeodactylum tricornutum. Nitrate reductase (NR) and nitrite reductase (NIR) are upregulated, but nitrate transporter (NRT) and glutamine synthetase (GS) are downregulated by MPs under nitrogen-limited conditions. In contrast, NR, NIR, and GS are all upregulated by MPs under nitrogen-replete conditions. MPs accelerate nitrogen anabolic processes with an increase in the accumulation of carbohydrates by 80.7 ± 7.9% and enhance the activities of key nitrogen-metabolizing enzymes (8.20-44.90%) under nitrogen-replete conditions. In contrast, the abundance of carbohydrates decreases by 22.0-34.4%, and NRT activity is inhibited by 79.0-86.5% in nitrogen-limited algae exposed to MPs. Metabolomic and transcriptomic analyses were performed to further explore the molecular mechanisms of reprogrammed nitrogen assimilation, including carbon metabolism, nitrogen transport and ammonia assimilation. The aforementioned spatial redistribution (e.g., the Matthew effect between nitrogen-replete and -limited conditions) of nitrogen assimilation highlights the potential risks of MP contamination in the ocean.
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Affiliation(s)
- Weilu Kang
- Key Laboratory of Pollution Processes and Environmental Criteria (Ministry of Education), Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China
| | - Shan Sun
- Key Laboratory of Pollution Processes and Environmental Criteria (Ministry of Education), Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China
| | - Xiangang Hu
- Key Laboratory of Pollution Processes and Environmental Criteria (Ministry of Education), Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China.
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10
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Yang N, Lin YA, Merkel CA, DeMers MA, Qu PP, Webb EA, Fu FX, Hutchins DA. Molecular mechanisms underlying iron and phosphorus co-limitation responses in the nitrogen-fixing cyanobacterium Crocosphaera. THE ISME JOURNAL 2022; 16:2702-2711. [PMID: 36008474 PMCID: PMC9666452 DOI: 10.1038/s41396-022-01307-7] [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: 02/27/2022] [Revised: 08/04/2022] [Accepted: 08/09/2022] [Indexed: 12/15/2022]
Abstract
In the nitrogen-limited subtropical gyres, diazotrophic cyanobacteria, including Crocosphaera, provide an essential ecosystem service by converting dinitrogen (N2) gas into ammonia to support primary production in these oligotrophic regimes. Natural gradients of phosphorus (P) and iron (Fe) availability in the low-latitude oceans constrain the biogeography and activity of diazotrophs with important implications for marine biogeochemical cycling. Much remains unknown regarding Crocosphaera's physiological and molecular responses to multiple nutrient limitations. We cultured C. watsonii under Fe, P, and Fe/P (co)-limiting scenarios to link cellular physiology with diel gene expression and observed unique physiological and transcriptional profiles for each treatment. Counterintuitively, reduced growth and N2 fixation resource use efficiencies (RUEs) for Fe or P under P limitation were alleviated under Fe/P co-limitation. Differential gene expression analyses show that Fe/P co-limited cells employ the same responses as single-nutrient limited cells that reduce cellular nutrient requirements and increase responsiveness to environmental change including smaller cell size, protein turnover (Fe-limited), and upregulation of environmental sense-and-respond systems (P-limited). Combined, these mechanisms enhance growth and RUEs in Fe/P co-limited cells. These findings are important to our understanding of nutrient controls on N2 fixation and the implications for primary productivity and microbial dynamics in a changing ocean.
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Affiliation(s)
- Nina Yang
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA
| | - Yu-An Lin
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA
| | - Carlin A Merkel
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA
| | - Michelle A DeMers
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA
| | - Ping-Ping Qu
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA, USA
| | - Eric A Webb
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA
| | - Fei-Xue Fu
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA
| | - David A Hutchins
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA.
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11
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Nair S, Zhang Z, Li H, Zhao H, Shen H, Kao SJ, Jiao N, Zhang Y. Inherent tendency of Synechococcus and heterotrophic bacteria for mutualism on long-term coexistence despite environmental interference. SCIENCE ADVANCES 2022; 8:eabf4792. [PMID: 36179022 PMCID: PMC9524826 DOI: 10.1126/sciadv.abf4792] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Accepted: 08/17/2022] [Indexed: 06/12/2023]
Abstract
Mutualism between Synechococcus and heterotrophic bacteria has been found to support their prolonged survival in nutrient-depleted conditions. However, environmental interference on the fate of their mutualism is not understood. Here, we show that exogenous nutrients disrupt their established mutualism. Once the exogenous nutrients were exhausted, Synechococcus and heterotrophic bacteria gradually reestablished their metabolic mutualism during 450 days of culture, which revived unhealthy Synechococcus cells. Using metagenomics, metatranscriptomics, and the 15N tracer method, we reveal that the associated bacterial nitrogen fixation triggered the reestablishment of the mutualism and revival of Synechococcus health. During this process, bacterial community structure and functions underwent tremendous adjustments to achieve the driving effect, and a cogeneration of nitrogen, phosphorus, iron, and vitamin by the heterotrophic bacteria sustained Synechococcus's prolonged healthy growth. Our findings suggest that Synechococcus and heterotrophic bacteria may have an inherent tendency toward mutualism despite environmental interference. This may exhibit their coevolutionary adaptations in nutrient-deficient environments.
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Affiliation(s)
- Shailesh Nair
- Shandong Provincial Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zenghu Zhang
- Shandong Provincial Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Hongmei Li
- Shandong Provincial Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Hanshuang Zhao
- Shandong Provincial Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Hui Shen
- State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen 361101, China
- State Key Laboratory of Marine Resource Utilization in the South China Sea, Hainan University, Haikou 570228, China
| | - Shuh-Ji Kao
- State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen 361101, China
- State Key Laboratory of Marine Resource Utilization in the South China Sea, Hainan University, Haikou 570228, China
| | - Nianzhi Jiao
- State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen 361101, China
| | - Yongyu Zhang
- Shandong Provincial Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
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12
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Strzepek RF, Nunn BL, Bach LT, Berges JA, Young EB, Boyd PW. The ongoing need for rates: can physiology and omics come together to co-design the measurements needed to understand complex ocean biogeochemistry? JOURNAL OF PLANKTON RESEARCH 2022; 44:485-495. [PMID: 35898813 PMCID: PMC9310281 DOI: 10.1093/plankt/fbac026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Accepted: 05/05/2022] [Indexed: 05/16/2023]
Abstract
The necessity to understand the influence of global ocean change on biota has exposed wide-ranging gaps in our knowledge of the fundamental principles that underpin marine life. Concurrently, physiological research has stagnated, in part driven by the advent and rapid evolution of molecular biological techniques, such that they now influence all lines of enquiry in biological oceanography. This dominance has led to an implicit assumption that physiology is outmoded, and advocacy that ecological and biogeochemical models can be directly informed by omics. However, the main modeling currencies are biological rates and biogeochemical fluxes. Here, we ask: how do we translate the wealth of information on physiological potential from omics-based studies to quantifiable physiological rates and, ultimately, to biogeochemical fluxes? Based on the trajectory of the state-of-the-art in biomedical sciences, along with case-studies from ocean sciences, we conclude that it is unlikely that omics can provide such rates in the coming decade. Thus, while physiological rates will continue to be central to providing projections of global change biology, we must revisit the metrics we rely upon. We advocate for the co-design of a new generation of rate measurements that better link the benefits of omics and physiology.
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Affiliation(s)
| | - Brook L Nunn
- Department of Genome Sciences, University of Washington, Foege Building S113 3720 15th Ave NE, Seattle, WA 98195, USA
| | - Lennart T Bach
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, TAS 7004, Australia
| | - John A Berges
- Department of Biological Sciences and School of Freshwater Sciences, University of Wisconsin-Milwaukee, 3209 N. Maryland Avenue, Milwaukee, WI 53211, USA
| | - Erica B Young
- Department of Biological Sciences and School of Freshwater Sciences, University of Wisconsin-Milwaukee, 3209 N. Maryland Avenue, Milwaukee, WI 53211, USA
| | - Philip W Boyd
- Australian Antarctic Program Partnership (AAPP), Institute for Marine and Antarctic Studies, University of Tasmania, 20 Castray Esplanade, Hobart, TAS 7004, Australia
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, TAS 7004, Australia
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13
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Identifying Algal Bloom ‘Hotspots’ in Marginal Productive Seas: A Review and Geospatial Analysis. REMOTE SENSING 2022. [DOI: 10.3390/rs14102457] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Algal blooms in the marginal productive seas of the Indian Ocean are projected to become more prevalent over the coming decades. They reach from lower latitudes up to the coast of the northern Indian Ocean and the populated areas along the Arabian Gulf, Sea of Oman, Arabian Sea, and the Red Sea. Studies that document algal blooms in the Indian Ocean have either focused on individual or regional waters or have been limited by a lack of long-term observations. Herein, we attempt to review the impact of major monsoons on algal blooms in the region and identify the most important oceanic and atmospheric processes that trigger them. The analysis is carried out using a comprehensive dataset collected from many studies focusing on the Indian Ocean. For the first time, we identify ten algal bloom hotspots and identify the primary drivers supporting algal blooms in them. Growth is found to depend on nutrients brought by dust, river runoff, upwelling, mixing, and advection, together with the availability of light, all being modulated by the phase of the monsoon. We also find that sunlight and dust deposition are strong predictors of algal bloom species and are essential for understanding marine biodiversity.
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14
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Cerdan-Garcia E, Baylay A, Polyviou D, Woodward EMS, Wrightson L, Mahaffey C, Lohan MC, Moore CM, Bibby TS, Robidart JC. Transcriptional responses of Trichodesmium to natural inverse gradients of Fe and P availability. THE ISME JOURNAL 2022; 16:1055-1064. [PMID: 34819612 PMCID: PMC8941076 DOI: 10.1038/s41396-021-01151-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 10/28/2021] [Accepted: 11/01/2021] [Indexed: 12/28/2022]
Abstract
The filamentous diazotrophic cyanobacterium Trichodesmium is responsible for a significant fraction of marine di-nitrogen (N2) fixation. Growth and distribution of Trichodesmium and other diazotrophs in the vast oligotrophic subtropical gyres is influenced by iron (Fe) and phosphorus (P) availability, while reciprocally influencing the biogeochemistry of these nutrients. Here we use observations across natural inverse gradients in Fe and P in the North Atlantic subtropical gyre (NASG) to demonstrate how Trichodesmium acclimates in situ to resource availability. Transcriptomic analysis identified progressive upregulation of known iron-stress biomarker genes with decreasing Fe availability, and progressive upregulation of genes involved in the acquisition of diverse P sources with decreasing P availability, while genes involved in N2 fixation were upregulated at the intersection under moderate Fe and P availability. Enhanced N2 fixation within the Fe and P co-stressed transition region was also associated with a distinct, consistent metabolic profile, including the expression of alternative photosynthetic pathways that potentially facilitate ATP generation required for N2 fixation with reduced net oxygen production. The observed response of Trichodesmium to availability of both Fe and P supports suggestions that these biogeochemically significant organisms employ unique molecular, and thus physiological responses as adaptations to specifically exploit the Fe and P co-limited niche they construct.
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Affiliation(s)
- E Cerdan-Garcia
- Ocean and Earth Science, University of Southampton, Southampton, SO14 3ZH, UK.
| | - A Baylay
- Ocean and Earth Science, University of Southampton, Southampton, SO14 3ZH, UK
| | - D Polyviou
- National Oceanography Centre, Southampton, SO14 3ZH, UK
| | | | - L Wrightson
- Earth, Ocean and Ecological Sciences, University of Liverpool, Liverpool, L69 3BX, UK
| | - C Mahaffey
- Earth, Ocean and Ecological Sciences, University of Liverpool, Liverpool, L69 3BX, UK
| | - M C Lohan
- Ocean and Earth Science, University of Southampton, Southampton, SO14 3ZH, UK
| | - C M Moore
- Ocean and Earth Science, University of Southampton, Southampton, SO14 3ZH, UK
| | - T S Bibby
- Ocean and Earth Science, University of Southampton, Southampton, SO14 3ZH, UK
| | - J C Robidart
- National Oceanography Centre, Southampton, SO14 3ZH, UK.
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15
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The marine nitrogen cycle: new developments and global change. Nat Rev Microbiol 2022; 20:401-414. [PMID: 35132241 DOI: 10.1038/s41579-022-00687-z] [Citation(s) in RCA: 51] [Impact Index Per Article: 25.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/07/2022] [Indexed: 12/25/2022]
Abstract
The ocean is home to a diverse and metabolically versatile microbial community that performs the complex biochemical transformations that drive the nitrogen cycle, including nitrogen fixation, assimilation, nitrification and nitrogen loss processes. In this Review, we discuss the wealth of new ocean nitrogen cycle research in disciplines from metaproteomics to global biogeochemical modelling and in environments from productive estuaries to the abyssal deep sea. Influential recent discoveries include new microbial functional groups, novel metabolic pathways, original conceptual perspectives and ground-breaking analytical capabilities. These emerging research directions are already contributing to urgent efforts to address the primary challenge facing marine microbiologists today: the unprecedented onslaught of anthropogenic environmental change on marine ecosystems. Ocean warming, acidification, nutrient enrichment and seawater stratification have major effects on the microbial nitrogen cycle, but widespread ocean deoxygenation is perhaps the most consequential for the microorganisms involved in both aerobic and anaerobic nitrogen transformation pathways. In turn, these changes feed back to the global cycles of greenhouse gases such as carbon dioxide and nitrous oxide. At a time when our species casts a lengthening shadow across all marine ecosystems, timely new advances offer us unique opportunities to understand and better predict human impacts on nitrogen biogeochemistry in the changing ocean of the Anthropocene.
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16
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Wang S, Koedooder C, Zhang F, Kessler N, Eichner M, Shi D, Shaked Y. Colonies of the marine cyanobacterium Trichodesmium optimize dust utilization by selective collection and retention of nutrient-rich particles. iScience 2022; 25:103587. [PMID: 35005537 PMCID: PMC8718973 DOI: 10.1016/j.isci.2021.103587] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 10/01/2021] [Accepted: 12/06/2021] [Indexed: 12/11/2022] Open
Abstract
Trichodesmium, a globally important, N2-fixing, and colony-forming cyanobacterium, employs multiple pathways for acquiring nutrients from air-borne dust, including active dust collection. Once concentrated within the colony core, dust can supply Trichodesmium with nutrients. Recently, we reported a selectivity in particle collection enabling Trichodesmium to center iron-rich minerals and optimize its nutrient utilization. In this follow-up study we examined if colonies select Phosphorus (P) minerals. We incubated 1,200 Trichodesmium colonies from the Red Sea with P-free CaCO3, P-coated CaCO3, and dust, over an entire bloom season. These colonies preferably interacted, centered, and retained P-coated CaCO3 compared with P-free CaCO3. In both studies, Trichodesmium clearly favored dust over all other particles tested, whereas nutrient-free particles were barely collected or retained, indicating that the colonies sense the particle composition and preferably collect nutrient-rich particles. This unique ability contributes to Trichodesmium's current ecological success and may assist it to flourish in future warmer oceans. Natural Trichodesmium colonies collect and maintain dust within their colony core Using synthetic particles we tested if colonies select the particles they collect Colonies selectively collect and retain nutrient-rich over nutrient-free particles Selective collection of particles optimizes their nutrient acquisition from dust
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Affiliation(s)
- Siyuan Wang
- The Freddy and Nadine Herrmann Institute of Earth Sciences, Edmond J. Safra Campus, Givat Ram, Hebrew University of Jerusalem, Jerusalem, Israel.,The Interuniversity Institute for Marine Sciences in Eilat, Eilat, Israel
| | - Coco Koedooder
- The Freddy and Nadine Herrmann Institute of Earth Sciences, Edmond J. Safra Campus, Givat Ram, Hebrew University of Jerusalem, Jerusalem, Israel.,The Interuniversity Institute for Marine Sciences in Eilat, Eilat, Israel.,Israel Limnology and Oceanography Research, Haifa, Israel
| | - Futing Zhang
- The Freddy and Nadine Herrmann Institute of Earth Sciences, Edmond J. Safra Campus, Givat Ram, Hebrew University of Jerusalem, Jerusalem, Israel.,The Interuniversity Institute for Marine Sciences in Eilat, Eilat, Israel.,State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, Fujian, People's Republic of China
| | - Nivi Kessler
- The Freddy and Nadine Herrmann Institute of Earth Sciences, Edmond J. Safra Campus, Givat Ram, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Meri Eichner
- Laboratory of Photosynthesis, Center Algatech, Institute of Microbiology of the Czech Academy of Sciences, Třeboň, Czech Republic
| | - Dalin Shi
- State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, Fujian, People's Republic of China
| | - Yeala Shaked
- The Freddy and Nadine Herrmann Institute of Earth Sciences, Edmond J. Safra Campus, Givat Ram, Hebrew University of Jerusalem, Jerusalem, Israel.,The Interuniversity Institute for Marine Sciences in Eilat, Eilat, Israel
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17
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Li L, Wu C, Huang D, Ding C, Wei Y, Sun J. Integrating Stochastic and Deterministic Process in the Biogeography of N 2-Fixing Cyanobacterium Candidatus Atelocyanobacterium Thalassa. Front Microbiol 2021; 12:654646. [PMID: 34745020 PMCID: PMC8566894 DOI: 10.3389/fmicb.2021.654646] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2021] [Accepted: 09/22/2021] [Indexed: 11/13/2022] Open
Abstract
UCYN-A is one of the most widespread and important marine diazotrophs. Its unusual distribution in both cold/warm and coastal/oceanic waters challenges current understanding about what drives the biogeography of diazotrophs. This study assessed the community assembly processes of the nitrogen-fixing cyanobacterium UCYN-A, developing a framework of assembly processes underpinning the microbial biogeography and diversity. High-throughput sequencing and a qPCR approach targeting the nifH gene were used to investigate three tropical seas: the Bay of Bengal, the Western Pacific Ocean, and the South China Sea. Based on the neutral community model and two types of null models calculating the β-nearest taxon index and the normalized stochasticity ratio, we found that stochastic assembly processes could explain 66-92% of the community assembly; thus, they exert overwhelming influence on UCYN-A biogeography and diversity. Among the deterministic processes, temperature and coastal/oceanic position appeared to be the principal environmental factors driving UCYN-A diversity. In addition, a close linkage between assembly processes and UCYN-A abundance/diversity/drivers can provide clues for the unusual global distribution of UCYN-A.
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Affiliation(s)
- Liuyang Li
- College of Marine Science and Technology, China University of Geosciences, Wuhan, China.,State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Chao Wu
- Research Centre for Indian Ocean Ecosystem, Tianjin University of Science and Technology, Tianjin, China
| | - Danyue Huang
- College of Marine Science and Technology, China University of Geosciences, Wuhan, China.,School of Oceanography, Shanghai Jiao Tong University, Shanghai, China
| | - Changling Ding
- Research Centre for Indian Ocean Ecosystem, Tianjin University of Science and Technology, Tianjin, China.,College of Biotechnology, Tianjin University of Science and Technology, Tianjin, China
| | - Yuqiu Wei
- Key Laboratory of Sustainable Development of Marine Fisheries, Ministry of Agriculture and Rural Affairs, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, China
| | - Jun Sun
- College of Marine Science and Technology, China University of Geosciences, Wuhan, China
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18
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Luo Z, Zhong Q, Han X, Hu R, Liu X, Xu W, Wu Y, Huang W, Zhou Z, Zhuang W, Yan Q, He Z, Wang C. Depth-dependent variability of biological nitrogen fixation and diazotrophic communities in mangrove sediments. MICROBIOME 2021; 9:212. [PMID: 34702367 PMCID: PMC8549172 DOI: 10.1186/s40168-021-01164-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Accepted: 09/17/2021] [Indexed: 05/29/2023]
Abstract
BACKGROUND Nitrogen-fixing prokaryotes (diazotrophs) contribute substantially to nitrogen input in mangrove sediments, and their structure and nitrogen fixation rate (NFR) are significantly controlled by environmental conditions. Despite the well-known studies on diazotrophs in surficial sediments, the diversity, structure, and ecological functions of diazotrophic communities along environmental gradients of mangrove sediment across different depths are largely unknown. Here, we investigated how biological nitrogen fixation varied with the depth of mangrove sediments from the perspectives of both NFR and diazotrophic communities. RESULTS Through acetylene reduction assay, nifH gene amplicon and metagenomic sequencing, we found that the NFR increased but the diversity of diazotrophic communities decreased with the depth of mangrove sediments. The structure of diazotrophic communities at different depths was largely driven by salinity and exhibited a clear divergence at the partitioning depth of 50 cm. Among diazotrophic genera correlated with NFR, Agrobacterium and Azotobacter were specifically enriched at 50-100 cm sediments, while Anaeromyxobacter, Rubrivivax, Methylocystis, Dickeya, and Methylomonas were more abundant at 0-50 cm. Consistent with the higher NFR, metagenomic analysis demonstrated the elevated abundance of nitrogen fixation genes (nifH/D/K) in deep sediments, where nitrification genes (amoA/B/C) and denitrification genes (nirK and norB) became less abundant. Three metagenome-assembled genomes (MAGs) of diazotrophs from deep mangrove sediments indicated their facultatively anaerobic and mixotrophic lifestyles as they contained genes for low-oxygen-dependent metabolism, hydrogenotrophic respiration, carbon fixation, and pyruvate fermentation. CONCLUSIONS This study demonstrates the depth-dependent variability of biological nitrogen fixation in terms of NFR and diazotrophic communities, which to a certain extent relieves the degree of nitrogen limitation in deep mangrove sediments. Video Abstract.
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Affiliation(s)
- Zhiwen Luo
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-sen University, Guangzhou, 510006, China
| | - Qiuping Zhong
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-sen University, Guangzhou, 510006, China
| | - Xingguo Han
- Institute of Biogeochemistry and Pollutant Dynamics, Swiss Federal Institute of Technology, Zurich (ETH Zurich), Universitätstrasse 16, 8092, Zurich, Switzerland
| | - Ruiwen Hu
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-sen University, Guangzhou, 510006, China
| | - Xingyu Liu
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-sen University, Guangzhou, 510006, China
| | - Wenjun Xu
- South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou, 510530, PR China
| | - Yongjie Wu
- South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou, 510530, PR China
| | - Weiming Huang
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-sen University, Guangzhou, 510006, China
| | - Zhengyuan Zhou
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-sen University, Guangzhou, 510006, China
| | - Wei Zhuang
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-sen University, Guangzhou, 510006, China
| | - Qingyun Yan
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-sen University, Guangzhou, 510006, China
| | - Zhili He
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-sen University, Guangzhou, 510006, China
| | - Cheng Wang
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-sen University, Guangzhou, 510006, China.
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19
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Turk-Kubo KA, Mills MM, Arrigo KR, van Dijken G, Henke BA, Stewart B, Wilson ST, Zehr JP. UCYN-A/haptophyte symbioses dominate N 2 fixation in the Southern California Current System. ISME COMMUNICATIONS 2021; 1:42. [PMID: 36740625 PMCID: PMC9723760 DOI: 10.1038/s43705-021-00039-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 07/22/2021] [Accepted: 07/26/2021] [Indexed: 02/07/2023]
Abstract
The availability of fixed nitrogen (N) is an important factor limiting biological productivity in the oceans. In coastal waters, high dissolved inorganic N concentrations were historically thought to inhibit dinitrogen (N2) fixation, however, recent N2 fixation measurements and the presence of the N2-fixing UCYN-A/haptophyte symbiosis in nearshore waters challenge this paradigm. We characterized the contribution of UCYN-A symbioses to nearshore N2 fixation in the Southern California Current System (SCCS) by measuring bulk community and single-cell N2 fixation rates, as well as diazotroph community composition and abundance. UCYN-A1 and UCYN-A2 symbioses dominated diazotroph communities throughout the region during upwelling and oceanic seasons. Bulk N2 fixation was detected in most surface samples, with rates up to 23.0 ± 3.8 nmol N l-1 d-1, and was often detected at the deep chlorophyll maximum in the presence of nitrate (>1 µM). UCYN-A2 symbiosis N2 fixation rates were higher (151.1 ± 112.7 fmol N cell-1 d-1) than the UCYN-A1 symbiosis (6.6 ± 8.8 fmol N cell-1 d-1). N2 fixation by the UCYN-A1 symbiosis accounted for a majority of the measured bulk rates at two offshore stations, while the UCYN-A2 symbiosis was an important contributor in three nearshore stations. This report of active UCYN-A symbioses and broad mesoscale distribution patterns establishes UCYN-A symbioses as the dominant diazotrophs in the SCCS, where heterocyst-forming and unicellular cyanobacteria are less prevalent, and provides evidence that the two dominant UCYN-A sublineages are separate ecotypes.
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Affiliation(s)
- Kendra A Turk-Kubo
- Ocean Sciences Department, University of California at Santa Cruz, Santa Cruz, CA, USA.
| | - Matthew M Mills
- Earth System Science, Stanford University, Stanford, CA, USA
| | - Kevin R Arrigo
- Earth System Science, Stanford University, Stanford, CA, USA
| | - Gert van Dijken
- Earth System Science, Stanford University, Stanford, CA, USA
| | - Britt A Henke
- Ocean Sciences Department, University of California at Santa Cruz, Santa Cruz, CA, USA
| | - Brittany Stewart
- Ocean Sciences Department, University of California at Santa Cruz, Santa Cruz, CA, USA
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA
| | - Samuel T Wilson
- Center for Microbial Oceanography: Research and Education, University of Hawai'i at Manoa, Honolulu, HI, USA
| | - Jonathan P Zehr
- Ocean Sciences Department, University of California at Santa Cruz, Santa Cruz, CA, USA
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20
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Benavides M, Conradt L, Bonnet S, Berman-Frank I, Barrillon S, Petrenko A, Doglioli A. Fine-scale sampling unveils diazotroph patchiness in the South Pacific Ocean. ISME COMMUNICATIONS 2021; 1:3. [PMID: 37938230 PMCID: PMC9723698 DOI: 10.1038/s43705-021-00006-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Revised: 02/17/2021] [Accepted: 02/22/2021] [Indexed: 06/01/2023]
Abstract
Diazotrophs are important contributors to nitrogen availability in the ocean. Oceanographic cruise data accumulated over the past three decades has revealed a heterogeneous distribution of diazotroph species at regional to global scales. However, dynamic fine-scale physical structures likely affect the distribution of diazotrophs at smaller spatiotemporal scales. The interaction between fine-scale ocean dynamics and diazotrophs remains poorly understood due to typically insufficient spatiotemporal sampling resolution and the lack of parallel detailed physical studies. Here we show the distribution of five groups of diazotrophs in the South Pacific at an unprecedented resolution of 7-16 km. We find a patchy distribution of diazotrophs, with each group being differentially affected by parameters describing fine-scale physical structures. The observed variability in species abundance and distribution would be masked by a coarser sampling resolution, highlighting the need to consider fine-scale physics to resolve the distribution of diazotrophs in the ocean.
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Affiliation(s)
- Mar Benavides
- Aix Marseille Univ, Université de Toulon, CNRS, IRD, MIO UM 110, Marseille, France.
| | - Louis Conradt
- Aix Marseille Univ, Université de Toulon, CNRS, IRD, MIO UM 110, Marseille, France
| | - Sophie Bonnet
- Aix Marseille Univ, Université de Toulon, CNRS, IRD, MIO UM 110, Marseille, France
| | - Ilana Berman-Frank
- Department of Marine Biology, Leon H. Charney School of Marine Sciences, University of Haifa, Mt. Carmel, Haifa, Israel
| | - Stéphanie Barrillon
- Aix Marseille Univ, Université de Toulon, CNRS, IRD, MIO UM 110, Marseille, France
| | - Anne Petrenko
- Aix Marseille Univ, Université de Toulon, CNRS, IRD, MIO UM 110, Marseille, France
| | - Andrea Doglioli
- Aix Marseille Univ, Université de Toulon, CNRS, IRD, MIO UM 110, Marseille, France
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21
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Wang S, Tang W, Delage E, Gifford S, Whitby H, González AG, Eveillard D, Planquette H, Cassar N. Investigating the microbial ecology of coastal hotspots of marine nitrogen fixation in the western North Atlantic. Sci Rep 2021; 11:5508. [PMID: 33750865 PMCID: PMC7943828 DOI: 10.1038/s41598-021-84969-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Accepted: 01/27/2021] [Indexed: 11/24/2022] Open
Abstract
Variation in the microbial cycling of nutrients and carbon in the ocean is an emergent property of complex planktonic communities. While recent findings have considerably expanded our understanding of the diversity and distribution of nitrogen (N2) fixing marine diazotrophs, knowledge gaps remain regarding ecological interactions between diazotrophs and other community members. Using quantitative 16S and 18S V4 rDNA amplicon sequencing, we surveyed eukaryotic and prokaryotic microbial communities from samples collected in August 2016 and 2017 across the Western North Atlantic. Leveraging and significantly expanding an earlier published 2015 molecular dataset, we examined microbial community structure and ecological co-occurrence relationships associated with intense hotspots of N2 fixation previously reported at sites off the Southern New England Shelf and Mid-Atlantic Bight. Overall, we observed a negative relationship between eukaryotic diversity and both N2 fixation and net community production (NCP). Maximum N2 fixation rates occurred at sites with high abundances of mixotrophic stramenopiles, notably Chrysophyceae. Network analysis revealed such stramenopiles to be keystone taxa alongside the haptophyte diazotroph host Braarudosphaera bigelowii and chlorophytes. Our findings highlight an intriguing relationship between marine stramenopiles and high N2 fixation coastal sites.
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Affiliation(s)
- Seaver Wang
- Division of Earth and Ocean Sciences, Duke University, Grainger Environment Hall, 9 Circuit Drive, Box 90328, Durham, NC, 27708, USA
| | - Weiyi Tang
- Department of Geosciences, Princeton University, Princeton, NJ, USA
| | - Erwan Delage
- LS2N, UMR 6004, CNRS, Université de Nantes, 44000, Nantes, France
| | - Scott Gifford
- Department of Marine Sciences, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Hannah Whitby
- Department of Earth, Ocean, and Ecological Sciences, School of Environmental Sciences, University of Liverpool, Liverpool, UK
| | - Aridane G González
- Instituto de Oceanografía y Cambio Global (IOCAG), Universidad de Las Palmas de Gran Canaria, ULPGC, Las Palmas, Spain.,Laboratoire des Sciences de l'Environnement Marin (LEMAR), Institut Universitaire Européen de la Mer (IUEM), Technopôle Brest-Iroise, 13 Plouzané, 29280, Locmaria-Plouzané, France
| | - Damien Eveillard
- LS2N, UMR 6004, CNRS, Université de Nantes, 44000, Nantes, France
| | - Hélène Planquette
- Laboratoire des Sciences de l'Environnement Marin (LEMAR), Institut Universitaire Européen de la Mer (IUEM), Technopôle Brest-Iroise, 13 Plouzané, 29280, Locmaria-Plouzané, France
| | - Nicolas Cassar
- Division of Earth and Ocean Sciences, Duke University, Grainger Environment Hall, 9 Circuit Drive, Box 90328, Durham, NC, 27708, USA. .,Laboratoire des Sciences de l'Environnement Marin (LEMAR), Institut Universitaire Européen de la Mer (IUEM), Technopôle Brest-Iroise, 13 Plouzané, 29280, Locmaria-Plouzané, France.
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