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Via CW, Grauso L, McManus KM, Kirk RD, Kim AM, Webb EA, Held NA, Saito MA, Scarpato S, Zimba PV, Moeller PDR, Mangoni A, Bertin MJ. Spatial and Temporal Resolution of Cyanobacterial Bloom Chemistry Reveals an Open-Ocean Trichodesmium thiebautii as a Talented Producer of Specialized Metabolites. Environ Sci Technol 2024. [PMID: 38758591 DOI: 10.1021/acs.est.3c10739] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2024]
Abstract
While the ecological role that Trichodesmium sp. play in nitrogen fixation has been widely studied, little information is available on potential specialized metabolites that are associated with blooms and standing stock Trichodesmium colonies. While a collection of biological material from a T. thiebautii bloom event from North Padre Island, Texas, in 2014 indicated that this species was a prolific producer of chlorinated specialized metabolites, additional spatial and temporal resolution was needed. We have completed these metabolite comparison studies, detailed in the current report, utilizing LC-MS/MS-based molecular networking to visualize and annotate the specialized metabolite composition of these Trichodesmium blooms and colonies in the Gulf of Mexico (GoM) and other waters. Our results showed that T. thiebautii blooms and colonies found in the GoM have a remarkably consistent specialized metabolome. Additionally, we isolated and characterized one new macrocyclic compound from T. thiebautii, trichothilone A (1), which was also detected in three independent cultures of T. erythraeum. Genome mining identified genes predicted to synthesize certain functional groups in the T. thiebautii metabolites. These results provoke intriguing questions of how these specialized metabolites affect Trichodesmium ecophysiology, symbioses with marine invertebrates, and niche development in the global oligotrophic ocean.
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Affiliation(s)
- Christopher W Via
- Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, University of Rhode Island, 7 Greenhouse Road, Kingston, Rhode Island 02881, United States
| | - Laura Grauso
- Dipartimento di Agraria, Università degli Studi di Napoli Federico II, via Universita 100, Portici Napoli 80055, Italy
| | - Kelly M McManus
- Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, University of Rhode Island, 7 Greenhouse Road, Kingston, Rhode Island 02881, United States
| | - Riley D Kirk
- Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, University of Rhode Island, 7 Greenhouse Road, Kingston, Rhode Island 02881, United States
| | - Andrew M Kim
- Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, University of Rhode Island, 7 Greenhouse Road, Kingston, Rhode Island 02881, United States
| | - Eric A Webb
- Marine and Environmental Biology, Department of Biological Sciences, University of Southern California, Los Angeles, California 90089, United States
| | - Noelle A Held
- Marine and Environmental Biology, Department of Biological Sciences, University of Southern California, Los Angeles, California 90089, United States
| | - Mak A Saito
- Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, United States
| | - Silvia Scarpato
- Dipartimento di Farmacia, Università degli Studi di Napoli Federico II, via Domenico Montesano 49, Napoli 80131, Italy
| | - Paul V Zimba
- Rice Rivers Center, Virginia Commonwealth University, Richmond, Virginia 23284, United States
| | - Peter D R Moeller
- Harmful Algal Bloom Monitoring and Reference Branch, Stressor Detection and Impacts Division, National Ocean Service/NOAA, Hollings Marine Laboratory, 331 Fort Johnson Road, Charleston, South Carolina 29412, United States
| | - Alfonso Mangoni
- Dipartimento di Farmacia, Università degli Studi di Napoli Federico II, via Domenico Montesano 49, Napoli 80131, Italy
| | - Matthew J Bertin
- Department of Chemistry, Case Western Reserve University, Cleveland, Ohio 44106, United States
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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. Biochim Biophys Acta Bioenerg 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] [What about the content of this article? (0)] [Affiliation(s)] [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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Koedooder C, Zhang F, Wang S, Basu S, Haley ST, Tolic N, Nicora CD, Glavina del Rio T, Dyhrman ST, Gledhill M, Boiteau RM, Rubin-Blum M, Shaked Y. Taxonomic distribution of metabolic functions in bacteria associated with Trichodesmium consortia. mSystems 2023; 8:e0074223. [PMID: 37916816 PMCID: PMC10734445 DOI: 10.1128/msystems.00742-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Accepted: 09/21/2023] [Indexed: 11/03/2023] Open
Abstract
IMPORTANCE Colonies of the cyanobacteria Trichodesmium act as a biological hotspot for the usage and recycling of key resources such as C, N, P, and Fe within an otherwise oligotrophic environment. While Trichodesmium colonies are known to interact and support a unique community of algae and particle-associated microbes, our understanding of the taxa that populate these colonies and the gene functions they encode is still limited. Characterizing the taxa and adaptive strategies that influence consortium physiology and its concomitant biogeochemistry is critical in a future ocean predicted to have increasingly resource-depleted regions.
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Affiliation(s)
- Coco Koedooder
- The Fredy and Nadine Herrmann Institute of Earth Sciences, Hebrew University of Jerusalem, Jerusalem, Israel
- The Interuniversity Institute for Marine Sciences in Eilat, Eilat, Israel
- Israel Oceanographic and Limnological Research, Haifa, Israel
| | - Futing Zhang
- The Fredy and Nadine Herrmann Institute of Earth Sciences, Hebrew University of Jerusalem, Jerusalem, Israel
- The Interuniversity Institute for Marine Sciences in Eilat, Eilat, Israel
| | - Siyuan Wang
- The Fredy and Nadine Herrmann Institute of Earth Sciences, Hebrew University of Jerusalem, Jerusalem, Israel
- The Interuniversity Institute for Marine Sciences in Eilat, Eilat, Israel
| | - Subhajit Basu
- The Fredy and Nadine Herrmann Institute of Earth Sciences, Hebrew University of Jerusalem, Jerusalem, Israel
- The Interuniversity Institute for Marine Sciences in Eilat, Eilat, Israel
- Microsensor Research Group, Max Planck Institute for Marine Microbiology, Bremen, Germany
| | - Sheean T. Haley
- Lamont-Doherty Earth Observatory, Columbia University, New York, USA
| | - Nikola Tolic
- Earth and Biological Sciences, Pacific Northwest National Laboratory, Richland, Washington, USA
| | - Carrie D. Nicora
- Earth and Biological Sciences, Pacific Northwest National Laboratory, Richland, Washington, USA
| | - Tijana Glavina del Rio
- Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, California, USA
| | - Sonya T. Dyhrman
- Lamont-Doherty Earth Observatory, Columbia University, New York, USA
- Department of Earth and Environmental Sciences, Columbia University, New York, USA
| | | | - Rene M. Boiteau
- Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington, USA
- College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, Corvallis, Oregon, USA
| | | | - Yeala Shaked
- The Fredy and Nadine Herrmann Institute of Earth Sciences, Hebrew University of Jerusalem, Jerusalem, Israel
- The Interuniversity Institute for Marine Sciences in Eilat, Eilat, Israel
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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Vase VK, Raman M, Sahay A, R S, K R, K R S, Dash G, J J, Rohit P, R RK. Dynamics of environmental variables during the incidence of algal bloom in the coastal waters of Gujarat along the northeastern Arabian Sea. Environ Monit Assess 2023; 195:1238. [PMID: 37736823 DOI: 10.1007/s10661-023-11827-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Accepted: 09/04/2023] [Indexed: 09/23/2023]
Abstract
The dynamics of physico-chemical, nutrient, and chlorophyll-a variables were studied in the bloom and non-bloom locations along the off-Gujarat coastal waters to understand the variability in biogeochemistry using multivariate analytical tests. The dissolved oxygen was significantly lower in the bloom stations (3.89 ± 0.44 mgL-1) than in the non-bloom stations (5.50 ± 0.70 mg L-1), due to the biological degradation of organic matter in addition to anaerobic microbial respiration. Nutrients (PO4 and NO3) and Chl-a concentrations were recorded higher in the bloom locations at 0.83 ± 0.21 µmol L-1, 4.47 ± 0.69 µmol L-1, 4.14 ± 1.49 mg m-3, respectively. PO4 and NO3 have shown a significantly higher positive correlation of r = 0.73 and r = 0.69 with Chl-a for bloom data than the non-bloom data. The percentage variance contributed by PC1 and PC2 for both bloom and non-bloom locations were estimated at 52.33%. The variable PO4 explains the highest 24.19% variability in PC1, followed by Chl-a (19.89%). The PO4 triggers the bloom formation and also correlates to the higher concentrations of Chl-a in the bloom locations. The bloom concentration ranges from 9553 to 12,235 trichomes L-1. The bloom intensity has shown a significant positive correlation with Chl-a (r = 0.77), NO3 (r = 0.56), and PO4 (r = 0.30), but a negative correlation was noticed with DO (r = - 0.63) and pH (r = - 0.49). The study also initiates a way forward research investigation on ocean-color technologies to identify and monitor blooms and climate change-driven factors for bloom formation. The occurrence of bloom and its influence on fishery resources and other marine biotas will open many research windows in marine fisheries, oceanography, remote sensing, marine biology, and trophodynamics.
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Affiliation(s)
- Vinaya Kumar Vase
- Mangalore University, Mangalagangotri, Mangaluru, Karnataka, 574199, India.
- ICAR-Central Marine Fisheries Research Institute, Ernakulam North, Kochi, Kerala, 682 018, India.
| | - Mini Raman
- ISRO-Space Application Center, Ahmadabad, Gujarat, India
| | - Arvind Sahay
- ISRO-Space Application Center, Ahmadabad, Gujarat, India
| | - Shikha R
- ICAR-Central Marine Fisheries Research Institute, Ernakulam North, Kochi, Kerala, 682 018, India
| | - Rajan K
- ICAR-Central Marine Fisheries Research Institute, Ernakulam North, Kochi, Kerala, 682 018, India
| | - Sreenath K R
- ICAR-Central Marine Fisheries Research Institute, Ernakulam North, Kochi, Kerala, 682 018, India
| | - Gyanaranjan Dash
- ICAR-Central Marine Fisheries Research Institute, Ernakulam North, Kochi, Kerala, 682 018, India
| | - Jayasankar J
- ICAR-Central Marine Fisheries Research Institute, Ernakulam North, Kochi, Kerala, 682 018, India
| | - Prathibha Rohit
- Mangalore University, Mangalagangotri, Mangaluru, Karnataka, 574199, India
- ICAR-Central Marine Fisheries Research Institute, Ernakulam North, Kochi, Kerala, 682 018, India
| | - Ratheesh Kumar R
- ICAR-Central Marine Fisheries Research Institute, Ernakulam North, Kochi, Kerala, 682 018, India
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Luo W, Luo YW. Diurnally dynamic iron allocation promotes N 2 fixation in marine dominant diazotroph Trichodesmium. Comput Struct Biotechnol J 2023; 21:3503-3512. [PMID: 37484493 PMCID: PMC10362294 DOI: 10.1016/j.csbj.2023.07.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 06/15/2023] [Accepted: 07/04/2023] [Indexed: 07/25/2023] Open
Abstract
Trichodesmium is the dominant photoautotrophic dinitrogen (N2) fixer (diazotroph) in the ocean. Iron is an important factor limiting growth of marine diazotrophs including Trichodesmium mainly because of high iron content of its N2-fixing enzyme, nitrogenase. However, it still lacks a quantitative understanding of how dynamic iron allocation among physiological processes acts to regulate growth and N2 fixation in Trichodesmium. Here, we constructed a model of Trichodesmium trichome in which intracellular iron could be dynamically re-allocated in photosystems and nitrogenase during the daytime. The results demonstrate that the dynamic iron allocation enhances modeled N2 fixation and growth rates of Trichodesmium, especially in iron-limited conditions, albeit having a marginal impact under high iron concentrations. Although the reuse of iron during a day is an apparent cause that dynamic iron allocation can benefit Trichodesmium under iron limitation, our model reveals two important mechanisms. First, the release of iron from photosystems downregulates the intracellular oxygen (O2) production and reduces the demand of respiratory protection, a process that Trichodesmium wastefully respires carbohydrates to create a lower O2 window for N2 fixation. Hence, more carbohydrates can be used in growth. Second, lower allocation of iron to nitrogenase during early daytime, a period when photosynthesis is active and intracellular O2 is high, reduces the amount of iron that is trapped in the inactivated nitrogenase induced by O2. This mechanism further increases the iron use efficiency in Trichodesmium. Overall, our study provides mechanistic and quantitative insight into the diurnal iron allocation that can alleviate iron limitation to Trichodesmium.
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Jiang Z, Zhu Y, Sun Z, Zhai H, Zhou F, Yan X, Chen Q, Chen J, Zeng J. Size-fractionated N 2 fixation off the Changjiang Estuary during summer. Front Microbiol 2023; 14:1189410. [PMID: 37228373 PMCID: PMC10203160 DOI: 10.3389/fmicb.2023.1189410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2023] [Accepted: 04/18/2023] [Indexed: 05/27/2023] Open
Abstract
Recent evidence has shown active N2 fixation in coastal eutrophic waters, yet the rate and controlling factors remain poorly understood, particularly in large estuaries. The Changjiang Estuary (CE) and adjacent shelf are characterized by fresh, nitrogen-replete Changjiang Diluted Water (CDW) and saline, nitrogen-depletion intruded Kuroshio water (Taiwan Warm Current and nearshore Kuroshio Branch Current), where N2 fixation may be contributed by different groups (i.e., Trichodesmium and heterotrophic diazotrophs). Here, for the first time, we provide direct measurement of size-fractionated N2 fixation rates (NFRs) off the CE during summer 2014 using the 15N2 bubble tracer method. The results demonstrated considerable spatial variations (southern > northern; offshore > inshore) in surface and depth-integrated NFRs, averaging 0.83 nmol N L-1 d-1 and 24.3 μmol N m-2 d-1, respectively. The highest bulk NFR (99.9 μmol N m-2 d-1; mostly contributed by >10 μm fraction) occurred in the southeastern East China Sea, where suffered from strong intrusion of the Kuroshio water characterized by low N/P ratio (<10) and abundant Trichodesmium (up to 10.23 × 106 trichomes m-2). However, low NFR (mostly contributed by <10 μm fraction) was detected in the CE controlled by the CDW, where NOx concentration (up to 80 μmol L-1) and N/P ratio (>100) were high and Trichodesmium abundance was low. The >10 μm fraction accounted for 60% of depth-integrated bulk NFR over the CE and adjacent shelf. We speculated that the present NFR of >10 μm fraction was mostly supported by Trichodesmium. Spearman rank correlation indicated that the NFR was significantly positively correlated with Trichodesmium abundance, salinity, temperature and Secchi depth, but was negatively with turbidity, N/P ratio, NOx, and chlorophyll a concentration. Our study suggests that distribution and size structure of N2 fixation off the CE are largely regulated by water mass (intruded Kuroshio water and CDW) movement and associated diazotrophs (particularly Trichodesmium) and nutrient conditions.
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Affiliation(s)
- Zhibing Jiang
- Key Laboratory of Marine Ecosystem Dynamics, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, China
- Key Laboratory of Ocean Space Resource Management Technology, Ministry of Natural Resource, Hangzhou, China
- Key Laboratory of Nearshore Engineering Environment and Ecological Security of Zhejiang Province, Hangzhou, China
- State Key Laboratory of Satellite Ocean Environment Dynamics, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, China
- Observation and Research Station of Marine Ecosystem in the Yangtze River Delta, Ministry of Natural Resources, Hangzhou, China
| | - Yuanli Zhu
- Key Laboratory of Marine Ecosystem Dynamics, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, China
- Key Laboratory of Ocean Space Resource Management Technology, Ministry of Natural Resource, Hangzhou, China
- Observation and Research Station of Marine Ecosystem in the Yangtze River Delta, Ministry of Natural Resources, Hangzhou, China
| | - Zhenhao Sun
- Key Laboratory of Marine Ecosystem Dynamics, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, China
| | - Hongchang Zhai
- Key Laboratory of Marine Ecosystem Dynamics, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, China
| | - Feng Zhou
- State Key Laboratory of Satellite Ocean Environment Dynamics, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, China
- Observation and Research Station of Marine Ecosystem in the Yangtze River Delta, Ministry of Natural Resources, Hangzhou, China
| | - Xiaojun Yan
- Marine Science and Technology College, Zhejiang Ocean University, Zhoushan, China
| | - Quanzhen Chen
- Key Laboratory of Marine Ecosystem Dynamics, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, China
| | - Jianfang Chen
- Key Laboratory of Marine Ecosystem Dynamics, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, China
- State Key Laboratory of Satellite Ocean Environment Dynamics, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, China
| | - Jiangning Zeng
- Key Laboratory of Marine Ecosystem Dynamics, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, China
- Key Laboratory of Ocean Space Resource Management Technology, Ministry of Natural Resource, Hangzhou, China
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Agarwal V, Inomura K, Mouw CB. Quantitative Analysis of the Trade-Offs of Colony Formation for Trichodesmium. Microbiol Spectr 2022; 10:e0202522. [PMID: 36374046 DOI: 10.1128/spectrum.02025-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
There is considerable debate about the benefits and trade-offs for colony formation in a major marine nitrogen fixer, Trichodesmium. To quantitatively analyze the trade-offs, we developed a metabolic model based on carbon fluxes to compare the performance of Trichodesmium colonies and free trichomes under different scenarios. Despite reported reductions in carbon fixation and nitrogen fixation rates for colonies relative to free trichomes, we found that model colonies can outperform individual cells in several cases. The formation of colonies can be advantageous when respiration rates account for a high proportion of the carbon fixation rate. Negative external influence on vital rates, such as mortality due to predation or micronutrient limitations, can also create a net benefit for colony formation relative to individual cells. In contrast, free trichomes also outcompete colonies in many scenarios, such as when respiration rates are equal for both colonies and individual cells or when there is a net positive external influence on rate processes (i.e., optimal environmental conditions regarding light and temperature or high nutrient availability). For both colonies and free trichomes, an increase in carbon fixation relative to nitrogen fixation rates would increase their relative competitiveness. These findings suggest that the formation of colonies in Trichodesmium might be linked to specific environmental and ecological circumstances. Our results provide a road map for empirical studies and models to evaluate the conditions under which colony formation in marine phytoplankton can be sustained in the natural environment. IMPORTANCE Trichodesmium is a marine filamentous cyanobacterium that fixes nitrogen and is an important contributor to the global nitrogen cycle. In the natural environment, Trichodesmium can exist as individual cells (trichomes) or as colonies (puffs and tufts). In this paper, we try to answer a longstanding question in marine microbial ecology: how does colony formation benefit the survival of Trichodesmium? To answer this question, we developed a carbon flux model that utilizes existing published rates to evaluate whether and when colony formation can be sustained. Enhanced respiration rates, influential external factors such as environmental conditions and ecological interactions, and variable carbon and nitrogen fixation rates can all create scenarios for colony formation to be a viable strategy. Our results show that colony formation is an ecologically beneficial strategy under specific conditions, enabling Trichodesmium to be a globally significant organism.
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Abstract
The dominant marine filamentous N2 fixer, Trichodesmium, conducts photosynthesis and N2 fixation during the daytime. Because N2 fixation is sensitive to O2, some previous studies suggested that spatial segregation of N2 fixation and photosynthesis is essential in Trichodesmium. However, this hypothesis conflicts with some observations where all the cells contain both photosystems and the N2-fixing enzyme nitrogenase. Here, we construct a systematic model simulating Trichodesmium metabolism, showing that the hypothetical spatial segregation is probably useless in increasing the Trichodesmium growth and N2 fixation, unless substances can efficiently transfer among cells with low loss to the environment. The model suggests that Trichodesmium accumulates fixed carbon in the morning and uses that in respiratory protection to reduce intracellular O2 during the mid-daytime, when photosynthesis is downregulated, allowing the occurrence of N2 fixation. A cell membrane barrier against O2 and alternative non-O2 evolving electron transfer also contribute to maintaining low intracellular O2. Our study provides a mechanism enabling N2 fixation despite the presence of photosynthesis across Trichodesmium. IMPORTANCE The filamentous Trichodesmium is a globally prominent marine nitrogen fixer. A long-standing paradox is that the nitrogen-fixing enzyme nitrogenase is sensitive to oxygen, but Trichodesmium conducts both nitrogen fixation and oxygen-evolving photosynthesis during the daytime. Previous studies using immunoassays reported that nitrogenase was limited in some specialized Trichodesmium cells (termed diazocytes), suggesting the necessity of spatial segregation of nitrogen fixation and photosynthesis. However, attempts using other methods failed to find diazocytes in Trichodesmium, causing controversy on the existence of the spatial segregation. Here, our physiological model shows that Trichodesmium can maintain low intracellular O2 in mid-daytime and achieve feasible nitrogen fixation and growth rates even without the spatial segregation, while the hypothetical spatial segregation might not be useful if substantial loss of substances to the environment occurs when they transfer among the Trichodesmium cells. Our study then suggests a possible mechanism by which Trichodesmium can survive without the spatial segregation.
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Fernandez E, Seymour JR, Petrou K. Phytoplankton Sources and Sinks of Dimethylsulphoniopropionate (DMSP) in Temperate Coastal Waters of Australia. Microorganisms 2022; 10:microorganisms10081539. [PMID: 36013957 PMCID: PMC9414068 DOI: 10.3390/microorganisms10081539] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Revised: 07/25/2022] [Accepted: 07/26/2022] [Indexed: 11/23/2022] Open
Abstract
The ecologically important organic sulfur compound, dimethylsulfoniopropionate (DMSP), is ubiquitous in marine environments. Produced by some species of phytoplankton and bacteria, it plays a key role in cellular responses to environmental change. Recently, uptake of DMSP by non-DMSP-producing phytoplankton species has been demonstrated, highlighting knowledge gaps concerning DMSP distribution through the marine microbial food web. In this study, we traced the uptake and distribution of DMSP through a natural marine microbial community collected from off the eastern coastline Australia. We found a diverse phytoplankton community representing six major taxonomic groups and conducted DMSP-enrichment experiments both on the whole community, and the community separated into large (≥8.0 µm), medium (3.0−8.0 µm), and small (0.2−3.0 µm) size fractions. Our results revealed active uptake of DMSP in all three size fractions of the community, with the largest fraction (>8 µm) forming the major DMSP sink, where enrichment resulted in an increase of DMSPp by 144%. We observed evidence for DMSP catabolism in all size fractions with DMSP enrichment, highlighting loss from the system via MeSH or DMS production. Based on taxonomic diversity, we postulate the sources of DMSP were the dinoflagellates, Phaeocystis sp., and Trichodesmium sp., which were present in a relatively high abundance, and the sinks for DMSP were the diatoms and picoeucaryotes in this temperate community. These findings corroborate the role of hitherto disregarded phytoplankton taxa as potentially important players in the cycling of DMSP in coastal waters of Australia and emphasize the need to better understand the fate of accumulated DMSP and its significance in cellular metabolism of non-DMSP producers.
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Affiliation(s)
- Eva Fernandez
- School of Life Sciences, University of Technology Sydney, Sydney, NSW 2007, Australia;
- Climate Change Cluster, University of Technology Sydney, Sydney, NSW 2007, Australia;
| | - Justin R. Seymour
- Climate Change Cluster, University of Technology Sydney, Sydney, NSW 2007, Australia;
| | - Katherina Petrou
- School of Life Sciences, University of Technology Sydney, Sydney, NSW 2007, Australia;
- Correspondence:
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Moisander PH, Daley MC, Shoemaker KM, Kolte V, Sharma G, Garlick K. Nitrogen Fixation Influenced by Phosphorus and Nitrogen Availability in the Benthic Bloom-forming Cyanobacterium Hydrocoleum sp. Identified in a Temperate Marine Lagoon. J Phycol 2022; 58:377-391. [PMID: 35212412 DOI: 10.1111/jpy.13244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Accepted: 01/02/2022] [Indexed: 06/14/2023]
Abstract
The nitrogen-fixing, non-heterocystous cyanobacterium Hydrocoleum sp. (Oscillatoriales) is a common epiphytic and benthic bloom-former in tropical and subtropical shallow water systems but shares high phylogenetic similarity with the planktonic, globally important diazotroph Trichodesmium. Multiphasic observations in this study resulted in unexpected identification of Hydrocoleum sp. in mass accumulations in a coastal lagoon in the Western temperate North Atlantic Ocean. Hydrocoleum physiology was examined in situ through measurements of N2 and CO2 fixation rates and expression of genes involved with N2 fixation, CO2 fixation, and phosphorus (P) stress. Bulk N2 fixation rates and Hydrocoleum nifH expression peaked at night and were strongly suppressed by dissolved inorganic nitrogen (DIN). The expression of high affinity phosphate transporter (pstS) and alkaline phosphatase (phoA) genes of Hydrocoleum was elevated during the night and negatively responded to phosphate amendments, as evidence that these mechanisms contribute to P acquisition during diazotrophic growth of Hydrocoleum in situ. This discovery at the edge of the previously known Hydrocoleum habitat range in the warming oceans raises intriguing questions about diazotrophic cyanobacterial adaptations and transitions on the benthic-pelagic continuum.
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Affiliation(s)
- Pia H Moisander
- Department of Biology, University of Massachusetts Dartmouth, 285 Old Westport Road, North Dartmouth, Massachusetts, 02747, USA
| | - Meaghan C Daley
- Department of Biology, University of Massachusetts Dartmouth, 285 Old Westport Road, North Dartmouth, Massachusetts, 02747, USA
| | - Katyanne M Shoemaker
- Department of Biology, University of Massachusetts Dartmouth, 285 Old Westport Road, North Dartmouth, Massachusetts, 02747, USA
- Graduate School of Oceanography, University of Rhode Island, Narragansett, Rhode Island, 02882, USA
| | - Vaishnavi Kolte
- Institute of Bioinformatics and Applied Biotechnology, Bengaluru, Karnataka, 560100, India
| | - Gaurav Sharma
- Institute of Bioinformatics and Applied Biotechnology, Bengaluru, Karnataka, 560100, India
| | - Kelsey Garlick
- Department of Biology, University of Massachusetts Dartmouth, 285 Old Westport Road, North Dartmouth, Massachusetts, 02747, USA
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12
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Zhu Y, Feng Y, Browning TJ, Wen Z, Hughes DJ, Hao Q, Zhang R, Meng Q, Wells ML, Jiang Z, Dissanayake PAKN, Priyadarshani WNC, Shou L, Zeng J, Chai F. Exploring Variability of Trichodesmium Photophysiology Using Multi-Excitation Wavelength Fast Repetition Rate Fluorometry. Front Microbiol 2022; 13:813573. [PMID: 35464918 PMCID: PMC9026164 DOI: 10.3389/fmicb.2022.813573] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Accepted: 02/11/2022] [Indexed: 11/20/2022] Open
Abstract
Fast repetition rate fluorometry (FRRf) allows for rapid non-destructive assessment of phytoplankton photophysiology in situ yet has rarely been applied to Trichodesmium. This gap reflects long-standing concerns that Trichodesmium (and other cyanobacteria) contain pigments that are less effective at absorbing blue light which is often used as the sole excitation source in FRR fluorometers-potentially leading to underestimation of key fluorescence parameters. In this study, we use a multi-excitation FRR fluorometer (equipped with blue, green, and orange LEDs) to investigate photophysiological variability in Trichodesmium assemblages from two sites. Using a multi-LED measurement protocol (447+519+634 nm combined), we assessed maximum photochemical efficiency (F v /F m ), functional absorption cross section of PSII (σ PSII ), and electron transport rates (ETRs) for Trichodesmium assemblages in both the Northwest Pacific (NWP) and North Indian Ocean in the vicinity of Sri Lanka (NIO-SL). Evaluating fluorometer performance, we showed that use of a multi-LED measuring protocol yields a significant increase of F v /F m for Trichodesmium compared to blue-only excitation. We found distinct photophysiological differences for Trichodesmium at both locations with higher average F v /F m as well as lower σ PSII and non-photochemical quenching (NPQ NSV ) observed in the NWP compared to the NIO-SL (Kruskal-Wallis t-test df = 1, p < 0.05). Fluorescence light response curves (FLCs) further revealed differences in ETR response with a lower initial slope (α ETR ) and higher maximum electron turnover rate ( E T R P S I I m a x ) observed for Trichodesmium in the NWP compared to the NIO-SL, translating to a higher averaged light saturation E K (= E T R P S I I m a x /α ETR ) for cells at this location. Spatial variations in physiological parameters were both observed between and within regions, likely linked to nutrient supply and physiological stress. Finally, we applied an algorithm to estimate primary productivity of Trichodesmium using FRRf-derived fluorescence parameters, yielding an estimated carbon-fixation rate ranging from 7.8 to 21.1 mgC mg Chl-a-1 h-1 across this dataset. Overall, our findings demonstrate that capacity of multi-excitation FRRf to advance the application of Chl-a fluorescence techniques in phytoplankton assemblages dominated by cyanobacteria and reveals novel insight into environmental regulation of photoacclimation in natural Trichodesmium populations.
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Affiliation(s)
- Yuanli Zhu
- State Key Laboratory of Satellite Ocean Environment Dynamics, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, China
- Key Laboratory of Marine Ecosystem Dynamics, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, China
| | - Yuanyuan Feng
- School of Oceanography, Shanghai Jiao Tong University, Shanghai, China
| | - Thomas J. Browning
- Marine Biogeochemistry Division, GEOMAR Helmholtz Centre for Ocean Research, Kiel, Germany
| | - Zuozhu Wen
- State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, China
| | - David J. Hughes
- Climate Change Cluster, Faculty of Science, University of Technology Sydney, Ultimo, NSW, Australia
| | - Qiang Hao
- State Key Laboratory of Satellite Ocean Environment Dynamics, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, China
- Key Laboratory of Marine Ecosystem Dynamics, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, China
| | - Ruifeng Zhang
- School of Oceanography, Shanghai Jiao Tong University, Shanghai, China
| | - Qicheng Meng
- State Key Laboratory of Satellite Ocean Environment Dynamics, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, China
| | - Mark L. Wells
- State Key Laboratory of Satellite Ocean Environment Dynamics, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, China
- Darling Marine Center, University of Maine, Walpole, ME, United States
| | - Zhibing Jiang
- Key Laboratory of Marine Ecosystem Dynamics, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, China
| | - P. A. K. N. Dissanayake
- Department of Oceanography and Marine Geology, Faculty of Fisheries and Marine Sciences and Technology, University of Ruhuna, Matara, Sri Lanka
| | - W. N. C. Priyadarshani
- National Institute of Oceanography and Marine Sciences, National Aquatic Resources Research and Development Agency, Colombo, Sri Lanka
| | - Lu Shou
- Key Laboratory of Marine Ecosystem Dynamics, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, China
| | - Jiangning Zeng
- Key Laboratory of Marine Ecosystem Dynamics, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, China
| | - Fei Chai
- State Key Laboratory of Satellite Ocean Environment Dynamics, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, China
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13
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Kelchner H, Reeve-Arnold KE, Schreiner KM, Bargu S, Roques KG, Errera RM. Domoic Acid and Pseudo-nitzschia spp. Connected to Coastal Upwelling along Coastal Inhambane Province, Mozambique: A New Area of Concern. Toxins (Basel) 2021; 13:903. [PMID: 34941740 PMCID: PMC8704230 DOI: 10.3390/toxins13120903] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 12/06/2021] [Accepted: 12/10/2021] [Indexed: 11/17/2022] Open
Abstract
Harmful algal blooms (HABs) are increasing globally in frequency, persistence, and geographic extent, posing a threat to ecosystem and human health. To date, no occurrences of marine phycotoxins have been recorded in Mozambique, which may be due to absence of a monitoring program and general awareness of potential threats. This study is the first documentation of neurotoxin, domoic acid (DA), produced by the diatom Pseudo-nitzschia along the east coast of Africa. Coastal Inhambane Province is a biodiversity hotspot where year-round Rhincodon typus (whale shark) sightings are among the highest globally and support an emerging ecotourism industry. Links between primary productivity and biodiversity in this area have not previously been considered or reported. During a pilot study, from January 2017 to April 2018, DA was identified year-round, peaking during Austral winter. During an intense study between May and August 2018, our research focused on identifying environmental factors influencing coastal productivity and DA concentration. Phytoplankton assemblage was diatom-dominated, with high abundances of Pseudo-nitzschia spp. Data suggest the system was influenced by nutrient pulses resulting from coastal upwelling. Continued and comprehensive monitoring along southern Mozambique would provide critical information to assess ecosystem and human health threats from marine toxins under challenges posed by global change.
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Affiliation(s)
- Holly Kelchner
- School of Renewable Natural Resources, Louisiana State University and Agricultural and Mechanical College, Baton Rouge, LA 70803, USA;
- Cooperative Institute for Great Lakes Research, University of Michigan, Ann Arbor, MI 48108, USA
| | - Katie E. Reeve-Arnold
- All Out Africa Marine Research Centre, Praia do Tofo, Inhambane 1300, Mozambique; (K.E.R.-A.); (K.G.R.)
| | - Kathryn M. Schreiner
- Large Lakes Observatory, University of Minnesota Duluth, Duluth, MI 55812, USA;
- Department of Chemistry & Biochemistry, University of Minnesota Duluth, Duluth, MN 55812, USA
| | - Sibel Bargu
- Department of Oceanography and Coastal Sciences, College of Coast and Environment, Louisiana State University and Agricultural and Mechanical College, Baton Rouge, LA 70803, USA;
| | - Kim G. Roques
- All Out Africa Marine Research Centre, Praia do Tofo, Inhambane 1300, Mozambique; (K.E.R.-A.); (K.G.R.)
| | - Reagan M. Errera
- School of Renewable Natural Resources, Louisiana State University and Agricultural and Mechanical College, Baton Rouge, LA 70803, USA;
- National Oceanic and Atmospheric Administration Great Lakes Environmental Research Laboratory, Ann Arbor, MI 48108, USA
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14
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Walworth NG, Saito MA, Lee MD, McIlvin MR, Moran DM, Kellogg RM, Fu FX, Hutchins DA, Webb EA. Why Environmental Biomarkers Work: Transcriptome-Proteome Correlations and Modeling of Multistressor Experiments in the Marine Bacterium Trichodesmium. J Proteome Res 2021; 21:77-89. [PMID: 34855411 DOI: 10.1021/acs.jproteome.1c00517] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Ocean microbial communities are important contributors to the global biogeochemical reactions that sustain life on Earth. The factors controlling these communities are being increasingly explored using metatranscriptomic and metaproteomic environmental biomarkers. Using published proteomes and transcriptomes from the abundant colony-forming cyanobacterium Trichodesmium (strain IMS101) grown under varying Fe and/or P limitation in low and high CO2, we observed robust correlations of stress-induced proteins and RNAs (i.e., involved in transport and homeostasis) that yield useful information on the nutrient status under low and/or high CO2. Conversely, transcriptional and translational correlations of many other central metabolism pathways exhibit broad discordance. A cellular RNA and protein production/degradation model demonstrates how biomolecules with small initial inventories, such as environmentally responsive proteins, achieve large increases in fold-change units as opposed to those with a higher basal expression and inventory such as metabolic systems. Microbial cells, due to their immersion in the environment, tend to show large adaptive responses in both RNA and protein that result in transcript-protein correlations. These observations and model results demonstrate multi-omic coherence for environmental biomarkers and provide the underlying mechanism for those observations, supporting the promise for global application in detecting responses to environmental stimuli in a changing ocean.
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Affiliation(s)
- Nathan G Walworth
- Marine and Environmental Biology, Department of Biological Sciences, University of Southern California, Los Angeles, California 90089, United States
| | - Mak A Saito
- Marine Chemistry and Geochemistry Department, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, United States
| | - Michael D Lee
- Blue Marble Space Institute of Science, Seattle, Washington 98104, United States.,Exobiology Branch, NASA Ames Research Center, Moffett Field, California 94035, United States
| | - Matthew R McIlvin
- Marine Chemistry and Geochemistry Department, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, United States
| | - Dawn M Moran
- Marine Chemistry and Geochemistry Department, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, United States
| | - Riss M Kellogg
- Marine Chemistry and Geochemistry Department, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, United States
| | - Fei-Xue Fu
- Marine and Environmental Biology, Department of Biological Sciences, University of Southern California, Los Angeles, California 90089, United States
| | - David A Hutchins
- Marine and Environmental Biology, Department of Biological Sciences, University of Southern California, Los Angeles, California 90089, United States
| | - Eric A Webb
- Marine and Environmental Biology, Department of Biological Sciences, University of Southern California, Los Angeles, California 90089, United States
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15
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Delmont TO. Discovery of nondiazotrophic Trichodesmium species abundant and widespread in the open ocean. Proc Natl Acad Sci U S A 2021; 118:e2112355118. [PMID: 34750267 DOI: 10.1073/pnas.2112355118] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/13/2021] [Indexed: 11/18/2022] Open
Abstract
Filamentous and colony-forming cells within the cyanobacterial genus Trichodesmium might account for nearly half of nitrogen fixation in the sunlit ocean, a critical mechanism that sustains plankton's primary productivity. Trichodesmium has long been portrayed as a diazotrophic genus. By means of genome-resolved metagenomics, here we reveal that nondiazotrophic Trichodesmium species not only exist but also are abundant and widespread in the open ocean, benefiting from a previously overlooked functional lifestyle to expand the biogeography of this prominent marine genus. Near-complete environmental genomes for those closely related candidate species reproducibly shared functional features including a lack of genes related to nitrogen fixation, hydrogen recycling, and hopanoid lipid production concomitant with the enrichment of nitrogen assimilation genes. Our results elucidate fieldwork observations of Trichodesmium cells fixing carbon but not nitrogen. The Black Queen hypothesis and burden of low-oxygen concentration requirements provide a rationale to explain gene loss linked to nitrogen fixation among Trichodesmium species. Disconnecting taxonomic signal for this genus from a microbial community's ability to fix nitrogen will help refine our understanding of the marine nitrogen balance. Finally, we are reminded that established links between taxonomic lineages and functional traits do not always hold true.
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16
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Qiu GW, Koedooder C, Qiu BS, Shaked Y, Keren N. Iron transport in cyanobacteria - from molecules to communities. Trends Microbiol 2021:S0966-842X(21)00133-5. [PMID: 34175176 DOI: 10.1016/j.tim.2021.06.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Revised: 06/01/2021] [Accepted: 06/01/2021] [Indexed: 11/22/2022]
Abstract
Iron is an essential micronutrient for the ecologically important photoautotrophic cyanobacteria which are found across diverse aquatic environments. Low concentrations and poor bioavailability of certain iron species exert a strong control on cyanobacterial growth, affecting ecosystem structure and biogeochemical cycling. Here, we review the iron-acquisition pathways cyanobacteria utilize for overcoming these challenges. As the molecular details of cyanobacterial iron transport are being uncovered, an overall scheme of how cyanobacteria handle and exploit this scarce and redox-active micronutrient is emerging. Importantly, the range of biological solutions used by cyanobacteria to increase iron fluxes goes beyond transport and includes behavioral traits of colonial cyanobacteria and intricate cyanobacteria-bacteria interactions.
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17
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Ding C, Wu C, Li L, Pujari L, Zhang G, Sun J. Comparison of Diazotrophic Composition and Distribution in the South China Sea and the Western Pacific Ocean. Biology (Basel) 2021; 10:555. [PMID: 34202962 PMCID: PMC8235572 DOI: 10.3390/biology10060555] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/23/2021] [Revised: 06/12/2021] [Accepted: 06/18/2021] [Indexed: 12/31/2022]
Abstract
The variation of diazotrophs has been elusive in multiple SCS and WPO regions due to insufficient data. Therefore, the dynamics of diazotrophic composition and distribution were investigated in this study, based on high-throughput sequencing and quantitative PCR of the nifH gene. We found that Proteobacteria dominated the diazotrophic community in the river-impacted SCS and cyanobacteria and Proteobacteria were more abundant in the ocean-dominated SCS and WPO. The qPCR analysis showed that cyanobacterial Trichodesmium was abundant in the Pearl River plume and in the SCS basin influenced by the Kuroshio intrusion, and it also thrived in the subequatorial region of the WPO. Unicellular cyanobacteria UCYN-A were mainly detected in the river-impacted area, UCYN-B was abundant in the WPO, UCYN-C had a relatively high abundance in the ocean-dominated area, and a preponderance of γ-Proteobacteria γ-24774A11 was observed in the ocean-dominated SCS and pelagic WPO. Diazotrophic communities had significant distance-decay relationships, reflecting clear biogeographic patterns in the study area. The variations of diazotrophic community structure were well explained by dissolved inorganic nitrogen, dissolved inorganic phosphate by an eigenvector spatial variable PCNM1. These results provide further information to help determine the ecological mechanism of elusive diazotrophic communities in different ocean ecosystems.
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Affiliation(s)
- Changling Ding
- Research Centre for Indian Ocean Ecosystem, Tianjin University of Science and Technology, Tianjin 300457, China; (C.D.); (C.W.); (L.L.); (L.P.); (G.Z.)
| | - Chao Wu
- Research Centre for Indian Ocean Ecosystem, Tianjin University of Science and Technology, Tianjin 300457, China; (C.D.); (C.W.); (L.L.); (L.P.); (G.Z.)
| | - Liuyang Li
- Research Centre for Indian Ocean Ecosystem, Tianjin University of Science and Technology, Tianjin 300457, China; (C.D.); (C.W.); (L.L.); (L.P.); (G.Z.)
| | - Laxman Pujari
- Research Centre for Indian Ocean Ecosystem, Tianjin University of Science and Technology, Tianjin 300457, China; (C.D.); (C.W.); (L.L.); (L.P.); (G.Z.)
| | - Guicheng Zhang
- Research Centre for Indian Ocean Ecosystem, Tianjin University of Science and Technology, Tianjin 300457, China; (C.D.); (C.W.); (L.L.); (L.P.); (G.Z.)
| | - Jun Sun
- Research Centre for Indian Ocean Ecosystem, Tianjin University of Science and Technology, Tianjin 300457, China; (C.D.); (C.W.); (L.L.); (L.P.); (G.Z.)
- College of Marine Science and Technology, China University of Geosciences (Wuhan), Wuhan 430074, China
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18
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Bell PRF. Analysis of satellite imagery using a simple algorithm supports evidence that Trichodesmium supplies a significant new nitrogen load to the GBR lagoon. Ambio 2021; 50:1200-1210. [PMID: 33454915 PMCID: PMC8068736 DOI: 10.1007/s13280-020-01460-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 10/21/2020] [Accepted: 11/30/2020] [Indexed: 06/12/2023]
Abstract
This work supports previous studies in the Great Barrier Reef lagoon that show the new nitrogen (N) load introduced by Trichodesmium is similar to or greater than that from riverine discharges. However, the current management programs aimed at improving the chronic eutrophic state of the GBR ignore the N load from Trichodesmium. These programs also ignore the evidence that Trichodesmium blooms could promote the bioavailability of heavy metals and be a source of toxins in the ciguatera food chain. Further work is urgently required to better quantify the potential impacts of Trichodesmium and develop management plans to reduce those impacts. A simple algorithm that uses MODIS imagery is developed for not only monitoring the spatial extent of Trichodesmium blooms but also for quantifying the concentration of those blooms. The algorithm is based on the readily available MODIS L2 data. A management plan that includes the harvesting of Trichodesmium is outlined.
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Affiliation(s)
- Peter R F Bell
- School of Chemical Engineering, University of Queensland, St Lucia, 4072, Australia.
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Wu C, Kan J, Liu H, Pujari L, Guo C, Wang X, Sun J. Heterotrophic Bacteria Dominate the Diazotrophic Community in the Eastern Indian Ocean (EIO) during Pre-Southwest Monsoon. Microb Ecol 2019; 78:804-819. [PMID: 31037377 DOI: 10.1007/s00248-019-01355-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Accepted: 03/05/2019] [Indexed: 06/09/2023]
Abstract
The diazotrophic communities play an important role in sustaining primary productivity through adding new nitrogen to oligotrophic marine ecosystems. Yet, their composition in the oligotrophic Indian Ocean is poorly understood. Here, we report the first observation of phylogenetic diversity and distribution of diazotrophs in the Eastern Indian Ocean (EIO) surface water (to 200 m) during the pre-southwest monsoon period. Through high throughput sequencing of nifH genes, we identified diverse groups of diazotrophs in the EIO including both non-cyanobacterial and cyanobacterial phylotypes. Proteobacteria (mainly Alpha-, Beta-, and Gamma-proteobacteria) were the most diverse and abundant groups within all the diazotrophs, which accounted for more than 86.9% of the total sequences. Cyanobacteria were also retrieved, and they were dominated by the filamentous non-heterocystous cyanobacteria Trichodesmium spp. Other cyanobacteria such as unicellular diazotrophic cyanobacteria were detected sporadically. Interestingly, our qPCR analysis demonstrated that the depth-integrated gene abundances of the diazotrophic communities exhibited spatial heterogeneity with Trichodesmium spp. appeared to be more abundant in the Bay of Bengal (p < 0.05), while Sagittula castanea (Alphaproteobacteria) was found to be more dominating in the equatorial region and offshores (p < 0.05). Non-metric multidimensional scaling analysis (NMDS) further confirmed distinct vertical and horizontal spatial variations in the EIO. Canonical correspondence analysis (CCA) indicated that temperature, salinity, and phosphate were the major environmental factors driving the distribution of the diazotroph communities. Overall, our study provides the first insight into the diversity and distribution of the diazotrophic communities in EIO. The findings from this study highlight distinct contributions of both non-cyanobacteria and cyanobacteria to N2 fixation. Moreover, our study reveals information that is critical for understanding spatial heterogeneity and distribution of diazotrophs, and their vital roles in nitrogen and carbon cycling.
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Affiliation(s)
- Chao Wu
- Institute of Marine Science and Technology, Shandong University, Qingdao, 266237, China
| | - Jinjun Kan
- Microbiology Division, Stroud Water Research Center, Avondale, PA, 19311, USA
| | - Haijiao Liu
- Institute of Marine Science and Technology, Shandong University, Qingdao, 266237, China
| | - Laxman Pujari
- Tianjin Key Laboratory of Marine Resources and Chemistry, Tianjin University of Science and Technology, Tianjin, 300457, China
- Research Centre for Indian Ocean Ecosystem, Tianjin University of science and Technology, Tianjin, 300457, China
| | - Congcong Guo
- Tianjin Key Laboratory of Marine Resources and Chemistry, Tianjin University of Science and Technology, Tianjin, 300457, China
- Research Centre for Indian Ocean Ecosystem, Tianjin University of science and Technology, Tianjin, 300457, China
| | - Xingzhou Wang
- Tianjin Key Laboratory of Marine Resources and Chemistry, Tianjin University of Science and Technology, Tianjin, 300457, China
- Research Centre for Indian Ocean Ecosystem, Tianjin University of science and Technology, Tianjin, 300457, China
| | - Jun Sun
- Tianjin Key Laboratory of Marine Resources and Chemistry, Tianjin University of Science and Technology, Tianjin, 300457, China.
- Research Centre for Indian Ocean Ecosystem, Tianjin University of science and Technology, Tianjin, 300457, China.
- College of Marine & Environmental Sciences, Tianjin University of Science and Technology, No.29 13th Avenue, TEDA, Tianjin, 300457, People's Republic of China.
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20
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Abstract
Trichodesmium is a major nitrogen-fixing cyanobacterium and exerts a significant influence on the oceanic nitrogen cycle. It is also a widely used model organism in laboratory studies. Since the nitrogen-fixing enzyme nitrogenase is extremely sensitive to oxygen, how these surface-dwelling plankton manage the two conflicting processes of nitrogen fixation and photosynthesis has been a long-standing question. In this study, we developed a simple model of metabolic fluxes of Trichodesmium capturing observed daily cycles of photosynthesis, nitrogen fixation, and boundary layer oxygen concentrations. The model suggests that forming a chain of cells for spatially segregating nitrogen fixation and photosynthesis is essential but not sufficient. It also requires a barrier against oxygen diffusion and high rates of oxygen scavenging by respiration. Finally, the model indicates that the life span of intracellular oxygen is extremely short, thus enabling cells to instantly create a low-oxygen environment upon deactivation of photosynthesis. The cyanobacterium Trichodesmium is an important contributor of new nitrogen (N) to the surface ocean, but its strategies for protecting the nitrogenase enzyme from inhibition by oxygen (O2) remain poorly understood. We present a dynamic physiological model to evaluate hypothesized conditions that would allow Trichodesmium to carry out its two conflicting metabolic processes of N2 fixation and photosynthesis. First, the model indicates that managing cellular O2 to permit N2 fixation requires high rates of respiratory O2 consumption. The energetic cost amounts to ∼80% of daily C fixation, comparable to the observed diminution of the growth rate of Trichodesmium relative to other phytoplankton. Second, by forming a trichome of connected cells, Trichodesmium can segregate N2 fixation from photosynthesis. The transfer of stored C to N-fixing cells fuels the respiratory O2 consumption that protects nitrogenase, while the reciprocal transfer of newly fixed N to C-fixing cells supports cellular growth. Third, despite Trichodesmium lacking the structural barrier found in heterocystous species, the model predicts low diffusivity of cell membranes, a function that may be explained by the presence of Gram-negative membrane, production of extracellular polysaccharide substances (EPS), and “buffer cells” that intervene between N2-fixing and photosynthetic cells. Our results suggest that all three factors—respiratory protection, trichome formation, and diffusion barriers—represent essential strategies that, despite their energetic costs, facilitate the growth of Trichodesmium in the oligotrophic aerobic ocean and permit it to be a major source of new reactive nitrogen. IMPORTANCETrichodesmium is a major nitrogen-fixing cyanobacterium and exerts a significant influence on the oceanic nitrogen cycle. It is also a widely used model organism in laboratory studies. Since the nitrogen-fixing enzyme nitrogenase is extremely sensitive to oxygen, how these surface-dwelling plankton manage the two conflicting processes of nitrogen fixation and photosynthesis has been a long-standing question. In this study, we developed a simple model of metabolic fluxes of Trichodesmium capturing observed daily cycles of photosynthesis, nitrogen fixation, and boundary layer oxygen concentrations. The model suggests that forming a chain of cells for spatially segregating nitrogen fixation and photosynthesis is essential but not sufficient. It also requires a barrier against oxygen diffusion and high rates of oxygen scavenging by respiration. Finally, the model indicates that the life span of intracellular oxygen is extremely short, thus enabling cells to instantly create a low-oxygen environment upon deactivation of photosynthesis.
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Eichner M, Basu S, Gledhill M, de Beer D, Shaked Y. Hydrogen Dynamics in Trichodesmium Colonies and Their Potential Role in Mineral Iron Acquisition. Front Microbiol 2019; 10:1565. [PMID: 31354665 PMCID: PMC6636555 DOI: 10.3389/fmicb.2019.01565] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Accepted: 06/24/2019] [Indexed: 12/14/2022] Open
Abstract
N2-fixing cyanobacteria mediate H2 fluxes through the opposing processes of H2 evolution, which is a by-product of the N2 fixation reaction, and H2 uptake, which is driven by uptake hydrogenases. Here, we used microelectrodes to characterize H2 and O2 dynamics in single natural colonies of the globally important N2 fixer Trichodesmium collected from the Gulf of Eilat. We observed gradually changing H2 dynamics over the course of the day, including both net H2 evolution and net H2 uptake, as well as large differences in H2 fluxes between individual colonies. Net H2 uptake was observed in colonies amended with H2 in both light and dark. Net H2 evolution was recorded in the light only, reflecting light-dependent N2 fixation coupled to H2 evolution. Both net H2 evolution and H2 uptake rates were higher before 2 pm than later in the day. These pronounced H2 dynamics in the morning coincided with strong net O2 uptake and the previously reported diel peak in N2 fixation. Later in the afternoon, when photosynthesis rates determined by O2 measurements were highest, and N2 fixation rates decrease according to previous studies, the H2 dynamics were also less pronounced. Thus, the observed diel variations in H2 dynamics reflect diel changes in the rates of O2 consumption and N2 fixation. Remarkably, the presence of H2 strongly stimulated the uptake of mineral iron by natural colonies. The magnitude of this effect was dependent on the time of day, with the strongest response in incubations that started before 2 pm, i.e., the period that covered the time of highest uptake hydrogenase activity. Based on these findings, we propose that by providing an electron source for mineral iron reduction in N2-fixing cells, H2 may contribute to iron uptake in Trichodesmium colonies.
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Affiliation(s)
- Meri Eichner
- Microsensor Group, Max Planck Institute for Marine Microbiology, Bremen, Germany
| | - Subhajit Basu
- The Freddy & Nadine Herrmann Institute of Earth Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
- The Interuniversity Institute for Marine Sciences in Eilat, Eilat, Israel
| | - Martha Gledhill
- GEOMAR Helmholtz Center for Ocean Research Kiel, Kiel, Germany
| | - Dirk de Beer
- Microsensor Group, Max Planck Institute for Marine Microbiology, Bremen, Germany
| | - Yeala Shaked
- The Freddy & Nadine Herrmann Institute of Earth Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
- The Interuniversity Institute for Marine Sciences in Eilat, Eilat, Israel
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Qu P, Fu FX, Kling JD, Huh M, Wang X, Hutchins DA. Distinct Responses of the Nitrogen-Fixing Marine Cyanobacterium Trichodesmium to a Thermally Variable Environment as a Function of Phosphorus Availability. Front Microbiol 2019; 10:1282. [PMID: 31244804 PMCID: PMC6579863 DOI: 10.3389/fmicb.2019.01282] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Accepted: 05/23/2019] [Indexed: 12/05/2022] Open
Abstract
Surface temperature in the ocean is projected to be elevated and more variable in the future, which will interact with other environmental changes like reduced nutrient supplies. To explore these multiple stressor relationships, we tested the influence of thermal variation on the key marine diazotrophic cyanobacterium Trichodesmium erythraeum GBRTRLI101 as a function of the limiting nutrient phosphorus (P). Two constant temperature treatments represented current winter (22°C) and summer (30°C) mean values. Three variable temperature treatments fluctuated around the constant control values: Mean 22°C, either ± 2°C or ± 4°C; and mean 30°C ± 2°C. Each thermal treatment was grown under both P-replete (10 μmol/L) and P-limiting conditions (0.2 μmol/L). Effects of thermal variability on Trichodesmium were mainly found in the two winter variable temperature treatments (22°C ± 2°C or ± 4°C). P availability affected growth and physiology in all treatments and had significant interactions with temperature. P-replete cultures had higher growth and nitrogen and carbon fixation rates in the 22°C constant control, than in the corresponding variable treatments. However, physiological rates were not different in the P-replete constant and variable treatments at 30°C. In contrast, in P-limited cultures an advantage of constant temperature over variable temperature was not apparent. Phosphorus use efficiencies (PUE, mol N or C fixed h-1 mol cellular P-1) for nitrogen and carbon fixation were significantly elevated under P-limited conditions, and increased with temperature from 22 to 30°C, implying a potential advantage in a future warmer, P-limited environment. Taken together, these results imply that future increasing temperature and greater thermal variability could have significant feedback interactions with the projected intensification of P-limitation of marine N2-fixing cyanobacteria.
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Affiliation(s)
- Pingping Qu
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, United States
| | - Fei-Xue Fu
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, United States
| | - Joshua D. Kling
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, United States
| | - Megan Huh
- Department of Preventive Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
| | - Xinwei Wang
- School of Life Sciences, Xiamen University, Xiamen, China
| | - David A. Hutchins
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, United States
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Frischkorn KR, Haley ST, Dyhrman ST. Transcriptional and Proteomic Choreography Under Phosphorus Deficiency and Re-supply in the N 2 Fixing Cyanobacterium Trichodesmium erythraeum. Front Microbiol 2019; 10:330. [PMID: 30891009 PMCID: PMC6411698 DOI: 10.3389/fmicb.2019.00330] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Accepted: 02/08/2019] [Indexed: 01/27/2023] Open
Abstract
The N2 fixing cyanobacterium Trichodesmium is a critically important organism in oligotrophic marine ecosystems, supplying “new” nitrogen (N) to the otherwise N-poor tropical and subtropical regions where it occurs. Low concentrations of phosphorus (P) in these regions can constrain Trichodesmium distribution and N2 fixation rates. Physiological characterization of a single species in a mixed community can be challenging, and ‘omic approaches are increasingly important tools for tracking nutritional physiology in a taxon-specific manner. As such, studies examining the dynamics of gene and protein markers of physiology (e.g., nutrient stress) are critical for the application and interpretation of such ‘omic data in situ. Here we leveraged combined transcriptomics, proteomics, and enzyme activity assays to track the physiological response of Trichodesmium erythraeum IMS101 to P deficiency and subsequent P re-supply over 72 h of sampling. P deficiency resulted in differential gene expression, protein abundance, and enzyme activity that highlighted a synchronous shift in P physiology with increases in the transcripts and corresponding proteins for hydrolyzing organic phosphorus, taking up phosphate with higher affinity, and modulating intracellular P demand. After P deficiency was alleviated, gene expression of these biomarkers was reduced to replete levels within 4 h of P amendment. A number of these gene biomarkers were adjacent to putative pho boxes and their expression patterns were similar to a sphR response regulator. Protein products of the P deficiency biomarkers were slow to decline, with 84% of the original P deficient protein set still significantly differentially expressed after 72 h. Alkaline phosphatase activity tracked with proteins for this enzyme. With the rapid turnover time of transcripts, they appear to be good biomarkers of a P stress phenotype, whereas proteins, with a slower turnover time, may better reflect cellular activities. These results highlight the importance of validating and pairing transcriptome and proteome data that can be applied to physiological studies of key species in situ.
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Affiliation(s)
- Kyle R Frischkorn
- Department of Earth and Environmental Sciences, Columbia University, New York, NY, United States.,Lamont-Doherty Earth Observatory, Palisades, NY, United States
| | - Sheean T Haley
- Lamont-Doherty Earth Observatory, Palisades, NY, United States
| | - Sonya T Dyhrman
- Department of Earth and Environmental Sciences, Columbia University, New York, NY, United States.,Lamont-Doherty Earth Observatory, Palisades, NY, United States
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Via CW, Glukhov E, Costa S, Zimba PV, Moeller PDR, Gerwick WH, Bertin MJ. The Metabolome of a Cyanobacterial Bloom Visualized by MS/MS-Based Molecular Networking Reveals New Neurotoxic Smenamide Analogs (C, D, and E). Front Chem 2018; 6:316. [PMID: 30094232 PMCID: PMC6071517 DOI: 10.3389/fchem.2018.00316] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Accepted: 07/09/2018] [Indexed: 11/29/2022] Open
Abstract
Members of the cyanobacterial genus Trichodesmium are well known for their substantial impact on nitrogen influx in ocean ecosystems and the enormous surface blooms they form in tropical and subtropical locations. However, the secondary metabolite composition of these complex environmental bloom events is not well known, nor the possibility of the production of potent toxins that have been observed in other bloom-forming marine and freshwater cyanobacteria species. In the present work, we aimed to characterize the metabolome of a Trichodesmium bloom utilizing MS/MS-based molecular networking. Furthermore, we integrated cytotoxicity assays in order to identify and ultimately isolate potential cyanotoxins from the bloom. These efforts led to the isolation and identification of several members of the smenamide family, including three new smenamide analogs (1-3) as well as the previously reported smenothiazole A-hybrid polyketide-peptide compounds. Two of these new smenamides possessed cytotoxicity to neuro-2A cells (1 and 3) and their presence elicits further questions as to their potential ecological roles. HPLC profiling and molecular networking of chromatography fractions from the bloom revealed an elaborate secondary metabolome, generating hypotheses with respect to the environmental role of these metabolites and the consistency of this chemical composition across genera, space and time.
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Affiliation(s)
- Christopher W. Via
- Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, University of Rhode Island, Kingston, RI, United States
| | - Evgenia Glukhov
- Center for Marine Biotechnology and Biomedicine, Skaggs School of Pharmacy and Pharmaceutical Sciences, Scripps Institution of Oceanography, University of California at San Diego, La Jolla, CA, United States
| | - Samuel Costa
- Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, University of Rhode Island, Kingston, RI, United States
| | - Paul V. Zimba
- Center for Coastal Studies and Department of Life Sciences, Texas A&M Corpus Christi, Corpus Christi, TX, United States
| | - Peter D. R. Moeller
- Emerging Toxins Program, Hollings Marine Laboratory, National Ocean Service/NOAA, Charleston, SC, United States
| | - William H. Gerwick
- Center for Marine Biotechnology and Biomedicine, Skaggs School of Pharmacy and Pharmaceutical Sciences, Scripps Institution of Oceanography, University of California at San Diego, La Jolla, CA, United States
| | - Matthew J. Bertin
- Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, University of Rhode Island, Kingston, RI, United States
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Liu J, Williams PC, Geisler-Lee J, Goodson BM, Fakharifar M, Peiravi M, Chen D, Lightfoot DA, Gemeinhardt ME. Impact of wastewater effluent containing aged nanoparticles and other components on biological activities of the soil microbiome, Arabidopsis plants, and earthworms. Environmental Research 2018; 164:197-203. [PMID: 29501007 DOI: 10.1016/j.envres.2018.02.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Revised: 01/04/2018] [Accepted: 02/05/2018] [Indexed: 05/16/2023]
Abstract
The amount of engineered nanomaterials (ENMs) in the environment has been increasing due to their industrial and commercial applications. Different types of metallic nanoparticles (NPs) have been detected in effluents from wastewater treatment plants (WWTPs). The effluents have been reclaimed for crop irrigation in many arid and semi-arid areas. Here, a soil micro-ecosystem was established including a microbiome, 4 Arabidopsis thaliana plants, and 3 Eisenia fetida earthworms, for a duration of 95 days. The impact of wastewater effluent (WE) containing aged NPs was studied. WE was taken from a local WWTP and exhibited the presence of Ti, Ag, and Zn up to 97.0 ± 9.4, 27.4 ± 3.9, and 4.1 ± 3.6 µg/L, respectively, as well as the presence of nanoscale particles (1-100 nm in diameter). The plants were irrigated with WE or deionized water (DIW). After 95 days, significantly higher concentrations of extractable Ti and Zn (439.2 ± 24.4 and 9.0 ± 0.5 mg/kg, respectively) were found in WE-irrigated soil than those in DIW-irrigated soil (161.2 ± 2.1 and 4.0 ± 0.1 mg/kg). The extractable Ag concentrations did not differ significantly between the WE- and DIW-irrigated soil. Although microbial biomass carbon and nitrogen were not significantly reduced, the population distribution of the microbial communities was shifted in WE-irrigated soil compared to the control. The abundance of cyanobacteria (Cyanophyta) was increased by 12.5% in the WE-irrigated soil as manifested mainly by an increase of Trichodesmium spp., and the abundance of unknown archaea was enhanced from 26.7% in the control to 40.5% in the WE-irrigated soil. The biomasses of A. thaliana and E. fetida were not significantly changed by WE exposure. However, A. thaliana had a noticeable shortened life cycle, and corrected total cell fluorescence was much higher in the roots of WE-irrigated plants compared to the control. These impacts on the soil micro-ecosystem may have resulted from the aged NPs and/or the metal ions released from these NPs, as well as other components in the WE. Taken together, these results should help inform the reuse of WE containing aged NPs and other components in sustainable agriculture.
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Affiliation(s)
- Jia Liu
- Department of Civil and Environmental Engineering, Southern Illinois University, 1230 Lincoln Dr., Carbondale, IL 62901, USA; Materials Technology Center, Southern Illinois University, 1230 Lincoln Dr., Carbondale, IL 62901, USA.
| | - Philip C Williams
- Department of Civil and Environmental Engineering, Southern Illinois University, 1230 Lincoln Dr., Carbondale, IL 62901, USA
| | - Jane Geisler-Lee
- Department of Plant Biology, Southern Illinois University, 1125 Lincoln Dr., Carbondale, IL 62901, USA
| | - Boyd M Goodson
- Department of Chemistry and Biochemistry, Southern Illinois University, 1245 Lincoln Dr., Carbondale, IL 62901, USA; Materials Technology Center, Southern Illinois University, 1230 Lincoln Dr., Carbondale, IL 62901, USA
| | - Masoud Fakharifar
- Department of Civil and Environmental Engineering, Southern Illinois University, 1230 Lincoln Dr., Carbondale, IL 62901, USA
| | - Meisam Peiravi
- Department of Civil and Environmental Engineering, Southern Illinois University, 1230 Lincoln Dr., Carbondale, IL 62901, USA
| | - Da Chen
- School of Environment, Guangzhou Key Laboratory of Environmental Exposure and Health, and Guangdong Key Laboratory of Environmental Pollution and Health, Jinan University, Guangzhou, Guangdong, China
| | - David A Lightfoot
- Department of Plant, Soil and Agricultural Systems, Southern Illinois University, 1205 Lincoln Dr., Carbondale, IL 62901, USA
| | - Max E Gemeinhardt
- Department of Chemistry and Biochemistry, Southern Illinois University, 1245 Lincoln Dr., Carbondale, IL 62901, USA
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26
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Polyviou D, Baylay AJ, Hitchcock A, Robidart J, Moore CM, Bibby TS. Desert Dust as a Source of Iron to the Globally Important Diazotroph Trichodesmium. Front Microbiol 2018; 8:2683. [PMID: 29387046 PMCID: PMC5776111 DOI: 10.3389/fmicb.2017.02683] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Accepted: 12/22/2017] [Indexed: 12/22/2022] Open
Abstract
The marine cyanobacterium Trichodesmium sp. accounts for approximately half of the annual ‘new’ nitrogen introduced to the global ocean but its biogeography and activity is often limited by the availability of iron (Fe). A major source of Fe to the open ocean is Aeolian dust deposition in which Fe is largely comprised of particles with reduced bioavailability over soluble forms of Fe. We report that Trichodesmium erythraeum IMS101 has improved growth rate and photosynthetic physiology and down-regulates Fe-stress biomarker genes when cells are grown in the direct vicinity of, rather than physically separated from, Saharan dust particles as the sole source of Fe. These findings suggest that availability of non-soluble forms of dust-associated Fe may depend on cell contact. Transcriptomic analysis further reveals unique profiles of gene expression in all tested conditions, implying that Trichodesmium has distinct molecular signatures related to acquisition of Fe from different sources. Trichodesmium thus appears to be capable of employing specific mechanisms to access Fe from complex sources in oceanic systems, helping to explain its role as a key microbe in global biogeochemical cycles.
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Affiliation(s)
- Despo Polyviou
- Ocean and Earth Science, University of Southampton, Waterfront Campus, Southampton, United Kingdom
| | - Alison J Baylay
- Ocean and Earth Science, University of Southampton, Waterfront Campus, Southampton, United Kingdom
| | - Andrew Hitchcock
- Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Sheffield, United Kingdom
| | - Julie Robidart
- Ocean Technology and Engineering Group, National Oceanography Centre, Southampton, United Kingdom
| | - C M Moore
- Ocean and Earth Science, University of Southampton, Waterfront Campus, Southampton, United Kingdom
| | - Thomas S Bibby
- Ocean and Earth Science, University of Southampton, Waterfront Campus, Southampton, United Kingdom
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Walworth NG, Fu FX, Lee MD, Cai X, Saito MA, Webb EA, Hutchins DA. Nutrient-Colimited Trichodesmium as a Nitrogen Source or Sink in a Future Ocean. Appl Environ Microbiol 2018; 84:e02137-17. [PMID: 29180365 DOI: 10.1128/AEM.02137-17] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Accepted: 11/16/2017] [Indexed: 11/20/2022] Open
Abstract
Nitrogen-fixing (N2) cyanobacteria provide bioavailable nitrogen to vast ocean regions but are in turn limited by iron (Fe) and/or phosphorus (P), which may force them to employ alternative nitrogen acquisition strategies. The adaptive responses of nitrogen fixers to global-change drivers under nutrient-limited conditions could profoundly alter the current ocean nitrogen and carbon cycles. Here, we show that the globally important N2 fixer Trichodesmium fundamentally shifts nitrogen metabolism toward organic-nitrogen scavenging following long-term high-CO2 adaptation under iron and/or phosphorus (co)limitation. Global shifts in transcripts and proteins under high-CO2/Fe-limited and/or P-limited conditions include decreases in the N2-fixing nitrogenase enzyme, coupled with major increases in enzymes that oxidize trimethylamine (TMA). TMA is an abundant, biogeochemically important organic nitrogen compound that supports rapid Trichodesmium growth while inhibiting N2 fixation. In a future high-CO2 ocean, this whole-cell energetic reallocation toward organic nitrogen scavenging and away from N2 fixation may reduce new-nitrogen inputs by Trichodesmium while simultaneously depleting the scarce fixed-nitrogen supplies of nitrogen-limited open-ocean ecosystems.IMPORTANCE Trichodesmium is among the most biogeochemically significant microorganisms in the ocean, since it supplies up to 50% of the new nitrogen supporting open-ocean food webs. We used Trichodesmium cultures adapted to high-CO2 conditions for 7 years, followed by additional exposure to iron and/or phosphorus (co)limitation. We show that "future ocean" conditions of high CO2 and concurrent nutrient limitation(s) fundamentally shift nitrogen metabolism away from nitrogen fixation and instead toward upregulation of organic nitrogen-scavenging pathways. We show that the responses of Trichodesmium to projected future ocean conditions include decreases in the nitrogen-fixing nitrogenase enzymes coupled with major increases in enzymes that oxidize the abundant organic nitrogen source trimethylamine (TMA). Such a shift toward organic nitrogen uptake and away from nitrogen fixation may substantially reduce new-nitrogen inputs by Trichodesmium to the rest of the microbial community in the future high-CO2 ocean, with potential global implications for ocean carbon and nitrogen cycling.
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Lee MD, Webb EA, Walworth NG, Fu FX, Held NA, Saito MA, Hutchins DA. Transcriptional Activities of the Microbial Consortium Living with the Marine Nitrogen-Fixing Cyanobacterium Trichodesmium Reveal Potential Roles in Community-Level Nitrogen Cycling. Appl Environ Microbiol 2018; 84:e02026-17. [PMID: 29054872 DOI: 10.1128/AEM.02026-17] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Accepted: 10/15/2017] [Indexed: 11/20/2022] Open
Abstract
Trichodesmium is a globally distributed cyanobacterium whose nitrogen-fixing capability fuels primary production in warm oligotrophic oceans. Like many photoautotrophs, Trichodesmium serves as a host to various other microorganisms, yet little is known about how this associated community modulates fluxes of environmentally relevant chemical species into and out of the supraorganismal structure. Here, we utilized metatranscriptomics to examine gene expression activities of microbial communities associated with Trichodesmium erythraeum (strain IMS101) using laboratory-maintained enrichment cultures that have previously been shown to harbor microbial communities similar to those of natural populations. In enrichments maintained under two distinct CO2 concentrations for ∼8 years, the community transcriptional profiles were found to be specific to the treatment, demonstrating a restructuring of overall gene expression had occurred. Some of this restructuring involved significant increases in community respiration-related transcripts under elevated CO2, potentially facilitating the corresponding measured increases in host nitrogen fixation rates. Particularly of note, in both treatments, community transcripts involved in the reduction of nitrate, nitrite, and nitrous oxide were detected, suggesting the associated organisms may play a role in colony-level nitrogen cycling. Lastly, a taxon-specific analysis revealed distinct ecological niches of consistently cooccurring major taxa that may enable, or even encourage, the stable cohabitation of a diverse community within Trichodesmium consortia.IMPORTANCETrichodesmium is a genus of globally distributed, nitrogen-fixing marine cyanobacteria. As a source of new nitrogen in otherwise nitrogen-deficient systems, these organisms help fuel carbon fixation carried out by other more abundant photoautotrophs and thereby have significant roles in global nitrogen and carbon cycling. Members of the Trichodesmium genus tend to form large macroscopic colonies that appear to perpetually host an association of diverse interacting microbes distinct from the surrounding seawater, potentially making the entire assemblage a unique miniature ecosystem. Since its first successful cultivation in the early 1990s, there have been questions about the potential interdependencies between Trichodesmium and its associated microbial community and whether the host's seemingly enigmatic nitrogen fixation schema somehow involved or benefited from its epibionts. Here, we revisit these old questions with new technology and investigate gene expression activities of microbial communities living in association with Trichodesmium.
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Belisle RS, Via CW, Schock TB, Villareal TA, Zimba PV, Beauchesne KR, Moeller PDR, Bertin MJ. Trichothiazole A, a dichlorinated polyketide containing an embedded thiazole isolated from Trichodesmium blooms. Tetrahedron Lett 2017; 58:4066-4068. [PMID: 32189813 PMCID: PMC7079771 DOI: 10.1016/j.tetlet.2017.09.027] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Mass spectrometry-guided isolation of the lipophilic extract of Trichodesmium bloom material led to the isolation and structure characterization of a new thiazole-containing di-chlorinated polyketide (1). The structure of 1 was deduced using 1D and 2D NMR analysis, high-resolution mass spectrometry analysis and complementary spectroscopic procedures. Trichothiazole A possesses interesting structural features, such as a terminal alkyne, two vinyl chlorides and a 2,4-disubstituted thiazole. Trichothiazole A showed moderate cytotoxicity to Neuro-2A cells (EC50: 13.3 ± 1.1 μM).
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Affiliation(s)
- Richard S. Belisle
- Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, University of Rhode Island, 7 Greenhouse Road, Kingston, RI 02881, United States
| | - Christopher W. Via
- Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, University of Rhode Island, 7 Greenhouse Road, Kingston, RI 02881, United States
| | - Tracey B. Schock
- National Institutes of Standards and Technology, Hollings Marine Laboratory, 331 Fort Johnson Road, Charleston, SC 29412, United States
| | - Tracy A. Villareal
- Marine Science Institute, University of Texas at Austin, 750 Channel View Drive, Port Aransas, Texas 78373, United States
| | - Paul V. Zimba
- Center for Coastal Studies and Department of Life Sciences, Texas A&M, Corpus Christi, 6300 Ocean Drive, Corpus Christi, TX 78412, United States
| | - Kevin R. Beauchesne
- Emerging Toxins Program, National Ocean Service/NOAA, Hollings Marine Laboratory, 331 Fort Johnson Road, Charleston, SC 29412, United States
| | - Peter D. R. Moeller
- Emerging Toxins Program, National Ocean Service/NOAA, Hollings Marine Laboratory, 331 Fort Johnson Road, Charleston, SC 29412, United States
| | - Matthew J. Bertin
- Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, University of Rhode Island, 7 Greenhouse Road, Kingston, RI 02881, United States
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Gradoville MR, Crump BC, Letelier RM, Church MJ, White AE. Corrigendum: Microbiome of Trichodesmium Colonies from the North Pacific Subtropical Gyre. Front Microbiol 2017; 8:1780. [PMID: 28947897 PMCID: PMC5610730 DOI: 10.3389/fmicb.2017.01780] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Accepted: 09/01/2017] [Indexed: 11/23/2022] Open
Affiliation(s)
- Mary R Gradoville
- College of Earth, Ocean and Atmospheric Sciences, Oregon State UniversityCorvallis, OR, United States
| | - Byron C Crump
- College of Earth, Ocean and Atmospheric Sciences, Oregon State UniversityCorvallis, OR, United States
| | - Ricardo M Letelier
- College of Earth, Ocean and Atmospheric Sciences, Oregon State UniversityCorvallis, OR, United States
| | - Matthew J Church
- Flathead Lake Biological Station, University of MontanaMT, United States
| | - Angelicque E White
- College of Earth, Ocean and Atmospheric Sciences, Oregon State UniversityCorvallis, OR, United States
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31
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Jyothibabu R, Karnan C, Jagadeesan L, Arunpandi N, Pandiarajan RS, Muraleedharan KR, Balachandran KK. Trichodesmium blooms and warm-core ocean surface features in the Arabian Sea and the Bay of Bengal. Mar Pollut Bull 2017; 121:201-215. [PMID: 28602311 DOI: 10.1016/j.marpolbul.2017.06.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2016] [Revised: 05/24/2017] [Accepted: 06/01/2017] [Indexed: 06/07/2023]
Abstract
Trichodesmium is a bloom-forming, diazotrophic, non-heterocystous cyanobacteria widely distributed in the warmer oceans, and their bloom is considered a 'biological indication' of stratification and nitrogen limitation in the ocean surface layer. In the first part of this paper, based on the retrospective analyses of the ocean surface mesoscale features associated with 59 Trichodesmium bloom incidences recorded in the past, 32 from the Arabian Sea and the Bay of Bengal, and 27 from the rest of the world, we have showed that warm-core features have an inducing effect on bloom formation. In the second part, we have considered the environmental preferences of Trichodesmium bloom based on laboratory and field studies across the globe, and proposed a view about how warm-core features could provide an inducing pre-requisite condition for the bloom formation in the Arabian Sea and the Bay of Bengal. Proposed that the subsurface waters of warm-core features maintain more likely chances for the conducive nutrient and light conditions required for the triggering of the blooms.
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Affiliation(s)
- R Jyothibabu
- CSIR-National Institute of Oceanography, Regional Centre, Kochi, India.
| | - C Karnan
- CSIR-National Institute of Oceanography, Regional Centre, Kochi, India
| | - L Jagadeesan
- CSIR-National Institute of Oceanography, Regional Centre, Kochi, India
| | - N Arunpandi
- CSIR-National Institute of Oceanography, Regional Centre, Kochi, India
| | - R S Pandiarajan
- CSIR-National Institute of Oceanography, Regional Centre, Kochi, India
| | - K R Muraleedharan
- CSIR-National Institute of Oceanography, Regional Centre, Kochi, India
| | - K K Balachandran
- CSIR-National Institute of Oceanography, Regional Centre, Kochi, India
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Gradoville MR, Crump BC, Letelier RM, Church MJ, White AE. Microbiome of Trichodesmium Colonies from the North Pacific Subtropical Gyre. Front Microbiol 2017; 8:1122. [PMID: 28729854 PMCID: PMC5498550 DOI: 10.3389/fmicb.2017.01122] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2016] [Accepted: 06/01/2017] [Indexed: 11/13/2022] Open
Abstract
Filamentous diazotrophic Cyanobacteria of the genus Trichodesmium, often found in colonial form, provide an important source of new nitrogen to tropical and subtropical marine ecosystems. Colonies are composed of several clades of Trichodesmium in association with a diverse community of bacterial and eukaryotic epibionts. We used high-throughput 16S rRNA and nifH gene sequencing, carbon (C) and dinitrogen (N2) fixation assays, and metagenomics to describe the diversity and functional potential of the microbiome associated with Trichodesmium colonies collected from the North Pacific Subtropical Gyre (NPSG). The 16S rRNA and nifH gene sequences from hand-picked colonies were predominantly (>99%) from Trichodesmium Clade I (i.e., T. thiebautii), which is phylogenetically and ecologically distinct from the Clade III IMS101 isolate used in most laboratory studies. The bacterial epibiont communities were dominated by Bacteroidetes, Alphaproteobacteria, and Gammaproteobacteria, including several taxa with a known preference for surface attachment, and were relatively depleted in the unicellular Cyanobacteria and small photoheterotrophic bacteria that dominate NPSG surface waters. Sequencing the nifH gene (encoding a subcomponent of the nitrogenase enzyme) identified non-Trichodesmium diazotrophs that clustered predominantly among the Cluster III nifH sequence-types that includes putative anaerobic diazotrophs. Trichodesmium colonies may represent an important habitat for these Cluster III diazotrophs, which were relatively rare in the surrounding seawater. Sequence analyses of nifH gene transcripts revealed several cyanobacterial groups, including heterocystous Richelia, associated with the colonies. Both the 16S rRNA and nifH datasets indicated strong differences between Trichodesmium epibionts and picoplankton in the surrounding seawater, and also between the epibionts inhabiting Trichodesmium puff and tuft colony morphologies. Metagenomic and 16S rRNA gene sequence analyses suggested that lineages typically associated with a copiotrophic lifestyle comprised a large fraction of colony-associated epibionts, in contrast to the streamlined genomes typical of bacterioplankton in these oligotrophic waters. Additionally, epibiont metagenomes were enriched in specific genes involved in phosphate and iron acquisition and denitrification pathways relative to surface seawater metagenomes. We propose that the unique microbial consortium inhabiting colonies has a significant impact on the biogeochemical functioning of Trichodesmium colonies in pelagic environments.
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Affiliation(s)
- Mary R Gradoville
- College of Earth, Ocean and Atmospheric Sciences, Oregon State UniversityCorvallis, OR, United States
| | - Byron C Crump
- College of Earth, Ocean and Atmospheric Sciences, Oregon State UniversityCorvallis, OR, United States
| | - Ricardo M Letelier
- College of Earth, Ocean and Atmospheric Sciences, Oregon State UniversityCorvallis, OR, United States
| | - Matthew J Church
- Flathead Lake Biological Station, University of MontanaMT, United States
| | - Angelicque E White
- College of Earth, Ocean and Atmospheric Sciences, Oregon State UniversityCorvallis, OR, United States
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Shunmugam S, Gayathri M, Prasannabalaji N, Thajuddin N, Muralitharan G. Unraveling the presence of multi-class toxins from Trichodesmium bloom in the Gulf of Mannar region of the Bay of Bengal. Toxicon 2017; 135:43-50. [PMID: 28606423 DOI: 10.1016/j.toxicon.2017.06.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Revised: 05/23/2017] [Accepted: 06/06/2017] [Indexed: 12/23/2022]
Abstract
Trichodesmium is an enigmatic bloom forming, non-heterocystous cyanobacterium reported most frequently in the coastal waters of India. However, the toxigenic potential of this globally significant N2 fixing cyanobacterium has not been characterized. In this study, we report for the first time the presence of potent multi-class neurotoxins such as Anatoxin-a, Saxitoxins, Gonyautoxin and hepatotoxins like MC-LR, MC-YA from a bloom material of Trichodesmium sp. MBDU 524 collected at the Gulf of Mannar region. Toxins were determined using liquid chromatography-electrospray ionization mass spectrometry (LC-ESI-MS) analysis of HPLC purified aqueous and solvent fractions. Molecular phylogenetic analysis through 16S rRNA gene sequencing showed the close relationship with Trichodesmium erythraeum clade. The toxigenic potential was validated through brine shrimp toxicity assay and showed 100% mortality after 48 h of incubation. The results suggest the potential toxigenic and environmental impacts of Trichodesmium bloom sample from the Gulf of Mannar region.
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Affiliation(s)
- Sumathy Shunmugam
- Department of Microbiology, Centre of Excellence in Life Sciences, Bharathidasan University, Tiruchirappalli, 620024, Tamilnadu, India
| | - Manickam Gayathri
- Department of Microbiology, Centre of Excellence in Life Sciences, Bharathidasan University, Tiruchirappalli, 620024, Tamilnadu, India
| | - Nainangu Prasannabalaji
- Department of Microbiology, Centre of Excellence in Life Sciences, Bharathidasan University, Tiruchirappalli, 620024, Tamilnadu, India
| | - Nooruddin Thajuddin
- Department of Microbiology, Centre of Excellence in Life Sciences, Bharathidasan University, Tiruchirappalli, 620024, Tamilnadu, India
| | - Gangatharan Muralitharan
- Department of Microbiology, Centre of Excellence in Life Sciences, Bharathidasan University, Tiruchirappalli, 620024, Tamilnadu, India.
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Dolan JR, Gimenez A, Cornet-Barthaux V, de Verneil A. Community Structure of Tintinnid Ciliates of the Microzooplankton in the South West Pacific Ocean: Comparison of a High Primary Productivity with a Typical Oligotrophic Site. J Eukaryot Microbiol 2016; 63:813-822. [PMID: 27218699 DOI: 10.1111/jeu.12328] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Revised: 05/10/2016] [Accepted: 05/17/2016] [Indexed: 11/26/2022]
Abstract
Transient 'hot spots' of phytoplankton productivity occur in the generally oligotrophic Southern Pacific Ocean and we hypothesized that the population structure of tintinnid ciliates, planktonic grazers, would differ from that of a typical oligotrophic sites. Samples were collected over a 1-wk period at each of two sites between Fiji and Tahiti: one of elevated chlorophyll a concentrations and primary productivity with an abundance of N-fixing cyanobacteria Trichodesmium, and a distant oligotrophic site. Tintinnid abundance differed between the sites by a factor of 2. A single species (Favella sp.), absent from the oligotrophic site, highly dominated the 'hot spot' site. However, total species richness was identical (71 spp.) as well as short-term temporal variability (2-4 d). At both sites, species abundance distributions most closely fit a log-series or log-normal distribution and the abundance distributions of ecological types, forms of distinct lorica oral diameter, were the typical geometric. Morphological diversity was only slightly lower at the high productivity site. We found that communities of these plankton grazers in 'hot spots' of phytoplankton productivity in oligotrophic systems, although harboring different species, differ little from surrounding oligotrophic areas in community structure.
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Affiliation(s)
- John R Dolan
- Sorbonne Universités, UPMC Univ Paris 06, CNRS UMR 7093, Laboratoire d'Océanographie de Villefranche de Villefranche-sur-Mer (LOV), Villefranche-sur-Mer, 06230, France.
| | - Audrey Gimenez
- MIO (Institut Méditerranéen d'Océanologie), Campus de Luminy, Marseille Cedex 9, 13288, France
| | | | - Alain de Verneil
- MIO (Institut Méditerranéen d'Océanologie), Campus de Luminy, Marseille Cedex 9, 13288, France
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Sargent EC, Hitchcock A, Johansson SA, Langlois R, Moore CM, LaRoche J, Poulton AJ, Bibby TS. Evidence for polyploidy in the globally important diazotroph Trichodesmium. FEMS Microbiol Lett 2016; 363:fnw244. [PMID: 27797867 DOI: 10.1093/femsle/fnw244] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 05/31/2016] [Accepted: 10/19/2016] [Indexed: 12/13/2022] Open
Abstract
Polyploidy is a well-described trait in some prokaryotic organisms; however, it is unusual in marine microbes from oligotrophic environments, which typically display a tendency towards genome streamlining. The biogeochemically significant diazotrophic cyanobacterium Trichodesmium is a potential exception. With a relatively large genome and a comparatively high proportion of non-protein-coding DNA, Trichodesmium appears to allocate relatively more resources to genetic material than closely related organisms and microbes within the same environment. Through simultaneous analysis of gene abundance and direct cell counts, we show for the first time that Trichodesmium spp. can also be highly polyploid, containing as many as 100 genome copies per cell in field-collected samples and >600 copies per cell in laboratory cultures. These findings have implications for the widespread use of the abundance of the nifH gene (encoding a subunit of the N2-fixing enzyme nitrogenase) as an approach for quantifying the abundance and distribution of marine diazotrophs. Moreover, polyploidy may combine with the unusual genomic characteristics of this genus both in reflecting evolutionary dynamics and influencing phenotypic plasticity and ecological resilience.
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Affiliation(s)
- Elizabeth C Sargent
- Ocean and Earth Science, University of Southampton, National Oceanography Centre Southampton, Southampton SO14 3ZH, UK
| | - Andrew Hitchcock
- Ocean and Earth Science, University of Southampton, National Oceanography Centre Southampton, Southampton SO14 3ZH, UK
| | - S Andreas Johansson
- Ocean and Earth Science, University of Southampton, National Oceanography Centre Southampton, Southampton SO14 3ZH, UK
| | - Rebecca Langlois
- Department of Biology, Life Science Centre, Dalhousie University, 1355 Oxford Street, Halifax, NS B3H 4R2, Canada
| | - C Mark Moore
- Ocean and Earth Science, University of Southampton, National Oceanography Centre Southampton, Southampton SO14 3ZH, UK
| | - Julie LaRoche
- Department of Biology, Life Science Centre, Dalhousie University, 1355 Oxford Street, Halifax, NS B3H 4R2, Canada
| | - Alex J Poulton
- Ocean Biogeochemistry and Ecosystems, National Oceanography Centre Southampton, Southampton SO14 3ZH, UK
| | - Thomas S Bibby
- Ocean and Earth Science, University of Southampton, National Oceanography Centre Southampton, Southampton SO14 3ZH, UK
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Rees AP, Tait K, Widdicombe CE, Quartly GD, McEvoy AJ, Al-Moosawi L. Metabolically active, non-nitrogen fixing, Trichodesmium in UK coastal waters during winter. J Plankton Res 2016; 38:673-678. [PMID: 27274100 PMCID: PMC4892227 DOI: 10.1093/plankt/fbv123] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/29/2015] [Accepted: 12/13/2015] [Indexed: 06/06/2023]
Abstract
Trichodesmium, a colonial cyanobacterium typically associated with tropical waters, was observed between January and April 2014 in the western English Channel. Sequencing of the heterocyst differentiation (hetR) and 16S rRNA genes placed this community within the Clade IV Trichodesmium, an understudied clade previously found only in low numbers in warmer waters. Nitrogen fixation was not detected although measurable rates of nitrate uptake and carbon fixation were observed. Trichodesmium RuBisCO transcript abundance relative to gene abundance suggests the potential for viable and potentially active Trichodesmium carbon fixation. Observations of Trichodesmium when coupled with a numerical advection model indicate that Trichodesmium communities can remain viable for >3.5 months at temperatures lower than previously expected. The results suggest that Clade IV Trichodesmium occupies a different niche to other Trichodesmium species, and is a cold- or low-light-adapted variant.
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Wolkowicz GSK, Yuan Y. Effect of light on the growth of non-nitrogen-fixing and nitrogen-fixing phytoplankton in an aquatic system. J Math Biol 2015; 72:1663-92. [PMID: 26316327 DOI: 10.1007/s00285-015-0924-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2014] [Revised: 05/28/2015] [Indexed: 11/28/2022]
Abstract
We discuss a mathematical model of growth of two types of phytoplankton, non-nitrogen-fixing and nitrogen-fixing, that both require light in order to grow. We use general functional responses to represent the inhibitory effect their biomass has on the exposure to light. We give conditions for the existence and local stability of all of the possible steady-states (die out, single species survival, and coexistence). We derive conditions for global stability of the die out and single-species steady-states and for persistence of both species when the coexistence steady-state exists. Numerical investigation illustrates the qualitative dynamics demonstrating that even under constant environmental conditions, both stable intrinsic oscillatory behavior and a period doubling route to chaotic dynamics are possible. We also show that competitor-mediated coexistence can occur due to the positive feedback resulting from recycling by the nitrogen-fixing phytoplankton. To show the impact of seasonal change in water depth, we also allow the water depth to vary in an annual cycle and discuss echo blooms in this context.
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Affiliation(s)
- Gail S K Wolkowicz
- Department of Mathematics and Statistics, McMaster University, Hamilton, ON, L8S 4K1, Canada
| | - Yuan Yuan
- Department of Mathematics and Statistics, Memorial University of Newfoundland, St. John's, NL, A1C 5S7, Canada.
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Abstract
We investigated the influence of varying cobalt (Co) and B12 concentrations to growth and nitrogen fixation of Trichodesmium, a major diazotroph in the tropical and subtropical oligotrophic ocean. Here we show that sufficient inorganic Co, 20 pmol L-1, sustains the growth of Trichodesmium either with or without an additional B12 supply. We also found that in these culture conditions, nitrogen levels fixed by Trichodesmium were higher in treatments with insufficient B12 than in treatments with higher B12 availability. Under limited inorganic Co availability, ranging from 0.2 to 2 pmol L-1, Trichodesmium growth was significantly compromised in cultures without B12. In these low Co concentrations, addition of 400 pmol L-1 of B12 supported phytoplankton growth indicating that B12 supply augmented for the low Co concentrations. Our study demonstrates that Trichodesmium has an absolute Co requirement, which is not replaceable with Zn, and that B12 supply alleviates stress in cases where Co is limiting. These results show that the interlocking availabilities of Co and B12 may influence the growth and nitrogen fixation of Trichodesmium in the ocean.
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Affiliation(s)
- Irene B Rodriguez
- Research Center for Environmental Changes - Academia Sinica Taipei, Taiwan
| | - Tung-Yuan Ho
- Research Center for Environmental Changes - Academia Sinica Taipei, Taiwan
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Price S, Anandan S. Characterization of a novel collagen-like protein TrpA in the cyanobacterium Trichodesmium erythraeum IMS101. J Phycol 2013; 49:758-764. [PMID: 27007208 DOI: 10.1111/jpy.12086] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2012] [Accepted: 04/26/2013] [Indexed: 06/05/2023]
Abstract
The collagen protein family is diverse and its membership is continually expanding as new collagen-like molecules are identified. Identification of collagen in unicellular eukaryotes and prokaryotes has opened discussion on the function of these collagens and their role in the emergence of multicellularity. The previous identification of a collagen gene in Trichodesmium erythraeum raises the question of function of this structural protein in a prokaryote. In this study, we show that this gene is expressed during all phases of growth, indicating that it may be required for all phases of growth. Using immunofluorescence techniques, we demonstrate that the collagen-like protein is localized in a specific manner between adjacent cells along the trichome of T. erythraeum. Trichomes treated with the enzyme collagenase exhibited fragmentation, supporting our immunofluorescence localization data that this collagen-like protein is found between adjacent cells. Our data strongly suggest that the collagen-like protein found in T. erythraeum functions to maintain the structural integrity of the trichome through the adhesion of adjacent cells.
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Affiliation(s)
- Simara Price
- Department of Biology, Drexel University, 3245 Chestnut Street, Philadelphia, Pennsylvania, 19104, USA
| | - Shivanthi Anandan
- Department of Biology, Drexel University, 3245 Chestnut Street, Philadelphia, Pennsylvania, 19104, USA
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Abstract
Our previous laboratory study revealed that insufficient Ni supply can limit nitrogen fixation in Trichodesmium, a primary diazotrophic phytoplankton in the tropical and subtropical oceans. Here we show that light intensity and Ni availability interrelate to influence Trichodesmium growth. Trichodesmium growth is severely inhibited under high light (670 μE m(-2) s(-1)) and insufficient Ni condition. On the contrary, the sufficient supply of Ni in seawater can sustain the growth of Trichodesmium under either high or low light conditions. We also observed elevated intracellular Ni uptake in Trichodesmium grown under relatively high light condition, supporting that the Ni requirement is used for removing superoxide generated through photosynthetic electron transport. This study shows that light saturation condition for Trichodesmium growth is Ni concentration dependent. This finding may exhibit implications for interpreting temporal and spatial distributions and activities of Trichodesmium in both modern and ancient oceans when light intensity and Ni concentrations have significantly varied.
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Affiliation(s)
- Tung-Yuan Ho
- Research Center for Environmental Changes Academia Sinica, Taipei, Taiwan
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Turk-Kubo KA, Achilles KM, Serros TRC, Ochiai M, Montoya JP, Zehr JP. Nitrogenase (nifH) gene expression in diazotrophic cyanobacteria in the Tropical North Atlantic in response to nutrient amendments. Front Microbiol 2012; 3:386. [PMID: 23130017 PMCID: PMC3487379 DOI: 10.3389/fmicb.2012.00386] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2012] [Accepted: 10/17/2012] [Indexed: 11/30/2022] Open
Abstract
The Tropical North Atlantic (TNAtl) plays a critical role in the marine nitrogen cycle, as it supports high rates of biological nitrogen (N2) fixation, yet it is unclear whether this process is limited by the availability of iron (Fe), phosphate (P) or is co-limited by both. In order to investigate the impact of nutrient limitation on the N2-fixing microorganisms (diazotrophs) in the TNAtl, trace metal clean nutrient amendment experiments were conducted, and the expression of nitrogenase (nifH) in cyanobacterial diazotrophs in response to the addition of Fe, P, or Fe+P was measured using quantitative PCR. To provide context, N2 fixation rates associated with the <10 μm community and diel nifH expression in natural cyanobacterial populations were measured. In the western TNAtl, nifH expression in Crocosphaera, Trichodesmium, and Richelia was stimulated by Fe and Fe+P additions, but not by P, implying that diazotrophs may be Fe-limited in this region. In the eastern TNAtl, nifH expression in unicellular cyanobacteria UCYN-A and Crocosphaera was stimulated by P, implying P-limitation. In equatorial waters, nifH expression in Trichodesmium was highest in Fe+P treatments, implying co-limitation in this region. Nutrient additions did not measurably stimulate N2 fixation rates in the <10 μm fraction in most of the experiments, even when upregulation of nifH expression was evident. These results demonstrate the utility of using gene expression to investigate the physiological state of natural populations of microorganisms, while underscoring the complexity of nutrient limitation on diazotrophy, and providing evidence that diazotroph populations are slow to respond to the addition of limiting nutrients and may be limited by different nutrients on basin-wide spatial scales. This has important implications for our current understanding of controls on N2 fixation in the TNAtl and may partially explain why it appears to be intermittently limited by Fe, P, or both.
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Affiliation(s)
- Kendra A Turk-Kubo
- Department of Ocean Sciences, University of California at Santa Cruz Santa Cruz, CA, USA
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Wilson ST, Kolber ZS, Tozzi S, Zehr JP, Karl DM. NITROGEN FIXATION, HYDROGEN CYCLING, AND ELECTRON TRANSPORT KINETICS IN TRICHODESMIUM ERYTHRAEUM (CYANOBACTERIA) STRAIN IMS101(1). J Phycol 2012; 48:595-606. [PMID: 27011075 DOI: 10.1111/j.1529-8817.2012.01166.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
This study describes the relationships between dinitrogen (N2 ) fixation, dihydrogen (H2 ) production, and electron transport associated with photosynthesis and respiration in the marine cyanobacterium Trichodesmium erythraeum Ehrenb. strain IMS101. The ratio of H2 produced:N2 fixed (H2 :N2 ) was controlled by the light intensity and by the light spectral composition and was affected by the growth irradiance level. For Trichodesmium cells grown at 50 μmol photons · m(-2) · s(-1) , the rate of N2 fixation, as measured by acetylene reduction, saturated at light intensities of 200 μmol photons · m(-2) · s(-1) . In contrast, net H2 production continued to increase with light levels up to 1,000 μmol photons · m(-2) · s(-1) . The H2 :N2 ratios increased monotonically with irradiance, and the variable fluorescence measured using a fast repetition rate fluorometer (FRRF) revealed that this increase was accompanied by a progressive reduction of the plastoquinone (PQ) pool. Additions of 2,5-dibromo-3-methyl-6-isopropyl-p-benzoquinone (DBMIB), an inhibitor of electron transport from PQ pool to PSI, diminished both N2 fixation and net H2 production, while the H2 :N2 ratio increased with increasing level of PQ pool reduction. In the presence of 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU), nitrogenase activity declined but could be prolonged by increasing the light intensity and by removing the oxygen supply. These results on the coupling of N2 fixation and H2 cycling in Trichodesmium indicate how light intensity and light spectral quality of the open ocean can influence the H2 :N2 ratio and modulate net H2 production.
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Affiliation(s)
- Samuel T Wilson
- Center for Microbial Oceanography: Research and Education, University of Hawaii, 1950 East-West Road, Honolulu, Hawaii 96822, USAOcean Sciences, University of California, Santa Cruz, California 95064, USACenter for Microbial Oceanography: Research and Education, University of Hawaii, 1950 East-West Road, Honolulu, Hawaii 96822, USA
| | - Zbigniew S Kolber
- Center for Microbial Oceanography: Research and Education, University of Hawaii, 1950 East-West Road, Honolulu, Hawaii 96822, USAOcean Sciences, University of California, Santa Cruz, California 95064, USACenter for Microbial Oceanography: Research and Education, University of Hawaii, 1950 East-West Road, Honolulu, Hawaii 96822, USA
| | - Sasha Tozzi
- Center for Microbial Oceanography: Research and Education, University of Hawaii, 1950 East-West Road, Honolulu, Hawaii 96822, USAOcean Sciences, University of California, Santa Cruz, California 95064, USACenter for Microbial Oceanography: Research and Education, University of Hawaii, 1950 East-West Road, Honolulu, Hawaii 96822, USA
| | - Jonathan P Zehr
- Center for Microbial Oceanography: Research and Education, University of Hawaii, 1950 East-West Road, Honolulu, Hawaii 96822, USAOcean Sciences, University of California, Santa Cruz, California 95064, USACenter for Microbial Oceanography: Research and Education, University of Hawaii, 1950 East-West Road, Honolulu, Hawaii 96822, USA
| | - David M Karl
- Center for Microbial Oceanography: Research and Education, University of Hawaii, 1950 East-West Road, Honolulu, Hawaii 96822, USAOcean Sciences, University of California, Santa Cruz, California 95064, USACenter for Microbial Oceanography: Research and Education, University of Hawaii, 1950 East-West Road, Honolulu, Hawaii 96822, USA
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Hynes AM, Webb EA, Doney SC, Waterbury JB. COMPARISON OF CULTURED TRICHODESMIUM (CYANOPHYCEAE) WITH SPECIES CHARACTERIZED FROM THE FIELD(1). J Phycol 2012; 48:196-210. [PMID: 27009664 DOI: 10.1111/j.1529-8817.2011.01096.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The filamentous, colonial cyanobacterium Trichodesmium has six well-described species, but many more names. Traditional classification was based on field samples using morphological characteristics such as cell width and length, gas vesicle distribution, and colony morphology. We used the Woods Hole Trichodesmium culture collection to identify 21 cultured strains to species using cell morphology; phycobiliprotein absorption spectra; and sequences of the 16S rRNA gene, the 16S-23S internal transcribed spacer (ITS), and the heterocyst differentiation gene hetR. We compared our results to previous studies of field specimens and found similar clades, though not all phylogenetic groups were represented in culture. Our culture collection represented two of the four major clades of Trichodesmium: clade I, made up of Trichodesmium thiebautii Gomont, Trichodesmium tenue Wille, Katagnymene spiralis Lemmerm., and Trichodesmium hildebrandtii Gomont; and clade III, consisting of Trichodesmium erythraeum Ehrenb. and Trichodesmium contortum Wille. These clades were genetically coherent with similar phycobiliprotein composition, but morphologically diverse. In the continual revision of cyanobacterial taxonomy, genetic and biochemical information is useful and informative complements to morphology for the development of a functional classification scheme.
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Affiliation(s)
- Annette M Hynes
- Massachusetts Institute of Technology-Woods Hole Oceanographic Institution, Joint Program in Oceanography/Applied Ocean Science and Engineering, Woods Hole, Massachusetts, USA Department of Biology, Woods Hole Oceanographic Institution, 266 Woods Hole Rd., Woods Hole, Massachusetts 02543, USADepartment of Biological Sciences, University of Southern California, 3616 Trousdale Parkway AHF 331, Los Angeles, California 90089, USADepartment of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, 266 Woods Hole Rd., Woods Hole, Massachusetts 02543, USADepartment of Biology, Woods Hole Oceanographic Institution, 266 Woods Hole Rd., Woods Hole, Massachusetts 02543, USA
| | - Eric A Webb
- Massachusetts Institute of Technology-Woods Hole Oceanographic Institution, Joint Program in Oceanography/Applied Ocean Science and Engineering, Woods Hole, Massachusetts, USA Department of Biology, Woods Hole Oceanographic Institution, 266 Woods Hole Rd., Woods Hole, Massachusetts 02543, USADepartment of Biological Sciences, University of Southern California, 3616 Trousdale Parkway AHF 331, Los Angeles, California 90089, USADepartment of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, 266 Woods Hole Rd., Woods Hole, Massachusetts 02543, USADepartment of Biology, Woods Hole Oceanographic Institution, 266 Woods Hole Rd., Woods Hole, Massachusetts 02543, USA
| | - Scott C Doney
- Massachusetts Institute of Technology-Woods Hole Oceanographic Institution, Joint Program in Oceanography/Applied Ocean Science and Engineering, Woods Hole, Massachusetts, USA Department of Biology, Woods Hole Oceanographic Institution, 266 Woods Hole Rd., Woods Hole, Massachusetts 02543, USADepartment of Biological Sciences, University of Southern California, 3616 Trousdale Parkway AHF 331, Los Angeles, California 90089, USADepartment of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, 266 Woods Hole Rd., Woods Hole, Massachusetts 02543, USADepartment of Biology, Woods Hole Oceanographic Institution, 266 Woods Hole Rd., Woods Hole, Massachusetts 02543, USA
| | - John B Waterbury
- Massachusetts Institute of Technology-Woods Hole Oceanographic Institution, Joint Program in Oceanography/Applied Ocean Science and Engineering, Woods Hole, Massachusetts, USA Department of Biology, Woods Hole Oceanographic Institution, 266 Woods Hole Rd., Woods Hole, Massachusetts 02543, USADepartment of Biological Sciences, University of Southern California, 3616 Trousdale Parkway AHF 331, Los Angeles, California 90089, USADepartment of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, 266 Woods Hole Rd., Woods Hole, Massachusetts 02543, USADepartment of Biology, Woods Hole Oceanographic Institution, 266 Woods Hole Rd., Woods Hole, Massachusetts 02543, USA
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Garcia NS, Fu FX, Breene CL, Bernhardt PW, Mulholland MR, Sohm JA, Hutchins DA. INTERACTIVE EFFECTS OF IRRADIANCE AND CO2 ON CO2 FIXATION AND N2 FIXATION IN THE DIAZOTROPH TRICHODESMIUM ERYTHRAEUM (CYANOBACTERIA)(1). J Phycol 2011; 47:1292-1303. [PMID: 27020353 DOI: 10.1111/j.1529-8817.2011.01078.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The diazotrophic cyanobacteria Trichodesmium spp. contribute approximately half of the known marine dinitrogen (N2 ) fixation. Rapidly changing environmental factors such as the rising atmospheric partial pressure of carbon dioxide (pCO2 ) and shallower mixed layers (higher light intensities) are likely to affect N2 -fixation rates in the future ocean. Several studies have documented that N2 fixation in laboratory cultures of T. erythraeum increased when pCO2 was doubled from present-day atmospheric concentrations (∼380 ppm) to projected future levels (∼750 ppm). We examined the interactive effects of light and pCO2 on two strains of T. erythraeum Ehrenb. (GBRTRLI101 and IMS101) in laboratory semicontinuous cultures. Elevated pCO2 stimulated gross N2 -fixation rates in cultures growing at 38 μmol quanta · m(-2 ) · s(-1) (GBRTRLI101 and IMS101) and 100 μmol quanta · m(-2 ) · s(-1) (IMS101), but this effect was reduced in both strains growing at 220 μmol quanta · m(-2 ) · s(-1) . Conversely, CO2 -fixation rates increased significantly (P < 0.05) in response to high pCO2 under mid- and high irradiances only. These data imply that the stimulatory effect of elevated pCO2 on CO2 fixation and N2 fixation by T. erythraeum is correlated with light. The ratio of gross:net N2 fixation was also correlated with light and trichome length in IMS101. Our study suggests that elevated pCO2 may have a strong positive effect on Trichodesmium gross N2 fixation in intermediate and bottom layers of the euphotic zone, but perhaps not in light-saturated surface layers. Climate change models must consider the interactive effects of multiple environmental variables on phytoplankton and the biogeochemical cycles they mediate.
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Affiliation(s)
- Nathan S Garcia
- Department of Biological Sciences, University of Southern California, Los Angeles, California 90089, USADepartment of Ocean, Earth and Atmospheric Sciences, Old Dominion University, Norfolk, Virginia 23529, USADepartment of Biological Sciences, University of Southern California, Los Angeles, California 90089, USA
| | - Fei-Xue Fu
- Department of Biological Sciences, University of Southern California, Los Angeles, California 90089, USADepartment of Ocean, Earth and Atmospheric Sciences, Old Dominion University, Norfolk, Virginia 23529, USADepartment of Biological Sciences, University of Southern California, Los Angeles, California 90089, USA
| | - Cynthia L Breene
- Department of Biological Sciences, University of Southern California, Los Angeles, California 90089, USADepartment of Ocean, Earth and Atmospheric Sciences, Old Dominion University, Norfolk, Virginia 23529, USADepartment of Biological Sciences, University of Southern California, Los Angeles, California 90089, USA
| | - Peter W Bernhardt
- Department of Biological Sciences, University of Southern California, Los Angeles, California 90089, USADepartment of Ocean, Earth and Atmospheric Sciences, Old Dominion University, Norfolk, Virginia 23529, USADepartment of Biological Sciences, University of Southern California, Los Angeles, California 90089, USA
| | - Margaret R Mulholland
- Department of Biological Sciences, University of Southern California, Los Angeles, California 90089, USADepartment of Ocean, Earth and Atmospheric Sciences, Old Dominion University, Norfolk, Virginia 23529, USADepartment of Biological Sciences, University of Southern California, Los Angeles, California 90089, USA
| | - Jill A Sohm
- Department of Biological Sciences, University of Southern California, Los Angeles, California 90089, USADepartment of Ocean, Earth and Atmospheric Sciences, Old Dominion University, Norfolk, Virginia 23529, USADepartment of Biological Sciences, University of Southern California, Los Angeles, California 90089, USA
| | - David A Hutchins
- Department of Biological Sciences, University of Southern California, Los Angeles, California 90089, USADepartment of Ocean, Earth and Atmospheric Sciences, Old Dominion University, Norfolk, Virginia 23529, USADepartment of Biological Sciences, University of Southern California, Los Angeles, California 90089, USA
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Kerbrat AS, Amzil Z, Pawlowiez R, Golubic S, Sibat M, Darius HT, Chinain M, Laurent D. First evidence of palytoxin and 42-hydroxy-palytoxin in the marine cyanobacterium Trichodesmium. Mar Drugs 2011; 9:543-560. [PMID: 21731549 PMCID: PMC3124972 DOI: 10.3390/md9040543] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2011] [Revised: 03/23/2011] [Accepted: 03/25/2011] [Indexed: 11/16/2022] Open
Abstract
Marine pelagic diazotrophic cyanobacteria of the genus Trichodesmium (Oscillatoriales) are widespread throughout the tropics and subtropics, and are particularly common in the waters of New Caledonia. Blooms of Trichodesmium are suspected to be a potential source of toxins in the ciguatera food chain and were previously reported to contain several types of paralyzing toxins. The toxicity of water-soluble extracts of Trichodesmium spp. were analyzed by mouse bioassay and Neuroblastoma assay and their toxic compounds characterized using liquid chromatography coupled with tandem mass spectrometry techniques. Here, we report the first identification of palytoxin and one of its derivatives, 42-hydroxy-palytoxin, in field samples of Trichodesmium collected in the New Caledonian lagoon. The possible role played by Trichodesmium blooms in the development of clupeotoxism, this human intoxication following the ingestion of plankton-eating fish and classically associated with Ostreopsis blooms, is also discussed.
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Affiliation(s)
- Anne Sophie Kerbrat
- Toulouse University, UPS, UMR152 UPS-IRD (PHARMA-DEV), 118, route de Narbonne, F-31062 Toulouse cedex 9, France; E-Mail:
- Research Institute for the Development (IRD), UMR152, 98848 Noumea, New Caledonia
| | - Zouher Amzil
- Laboratory of Phycotoxins, IFREMER, Rue de l’Ile d’Yeu, BP21105, F-44311 Nantes cedex 3, France; E-Mails: (Z.A.); (M.S.)
| | - Ralph Pawlowiez
- Laboratory of toxic micro-algae (LMT), Louis Malarde Institute (ILM), BP30, 98713 Papeete, Tahiti, French Polynesia; E-Mails: (R.P.); (H.T.D.); (M.C.)
| | - Stjepko Golubic
- Biological Science Center, Boston University, 5 Cummington Street, Boston, MA 02215, USA; E-Mail:
| | - Manoella Sibat
- Laboratory of Phycotoxins, IFREMER, Rue de l’Ile d’Yeu, BP21105, F-44311 Nantes cedex 3, France; E-Mails: (Z.A.); (M.S.)
| | - Helene Taiana Darius
- Laboratory of toxic micro-algae (LMT), Louis Malarde Institute (ILM), BP30, 98713 Papeete, Tahiti, French Polynesia; E-Mails: (R.P.); (H.T.D.); (M.C.)
| | - Mireille Chinain
- Laboratory of toxic micro-algae (LMT), Louis Malarde Institute (ILM), BP30, 98713 Papeete, Tahiti, French Polynesia; E-Mails: (R.P.); (H.T.D.); (M.C.)
| | - Dominique Laurent
- Toulouse University, UPS, UMR152 UPS-IRD (PHARMA-DEV), 118, route de Narbonne, F-31062 Toulouse cedex 9, France; E-Mail:
- Research Institute for the Development (IRD), UMR152, 98713 Papeete, Tahiti, French Polynesia
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +689-47-42-16; Fax: +689-42-95-55
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Goebel NL, Edwards CA, Carter BJ, Achilles KM, Zehr JP. GROWTH AND CARBON CONTENT OF THREE DIFFERENT-SIZED DIAZOTROPHIC CYANOBACTERIA OBSERVED IN THE SUBTROPICAL NORTH PACIFIC(1). J Phycol 2008; 44:1212-1220. [PMID: 27041718 DOI: 10.1111/j.1529-8817.2008.00581.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
To develop tools for modeling diazotrophic growth in the open ocean, we determined the maximum growth rate and carbon content for three diazotrophic cyanobacteria commonly observed at Station ALOHA (A Long-term Oligotrophic Habitat Assessment) in the subtropical North Pacific: filamentous nonheterocyst-forming Trichodesmium and unicellular Groups A and B. Growth-irradiance responses of Trichodesmium erythraeum Ehrenb. strain IMS101 and Crocosphaera watsonii J. Waterbury strain WH8501 were measured in the laboratory. No significant differences were detected between their fitted parameters (±CI) for maximum growth rate (0.51 ± 0.09 vs. 0.49 ± 0.17 d(-1) ), half-light saturation (73 ± 29 vs. 66 ± 37 μmol quanta · m(-2) · s(-1) ), and photoinhibition (0 and 0.00043 ± 0.00087 [μmol quanta · m(-2) · s(-1) ](-1) ). Maximum growth rates and carbon contents of Trichodesmium and Crocosphaera cultures conformed to published allometric relationships, demonstrating that these relationships apply to oceanic diazotrophic microorganisms. This agreement promoted the use of allometric models to approximate unknown parameters of maximum growth rate (0.77 d(-1) ) and carbon content (480 fg C · μm(-3) ) for the uncultivated, unicellular Group A cyanobacteria. The size of Group A was characterized from samples from the North Pacific Ocean using fluorescence-activated cell sorting and real-time quantitative PCR techniques. Knowledge of growth and carbon content properties of these organisms facilitates the incorporation of different types of cyanobacteria in modeling efforts aimed at assessing the relative importance of filamentous and unicellular diazotrophs to carbon and nitrogen cycling in the open ocean.
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Affiliation(s)
- Nicole L Goebel
- Institute of Marine Sciences, University of California, Santa Cruz, California 95064, USAOcean Sciences Department, University of California, Santa Cruz, California 95064, USA
| | - Christopher A Edwards
- Institute of Marine Sciences, University of California, Santa Cruz, California 95064, USAOcean Sciences Department, University of California, Santa Cruz, California 95064, USA
| | - Brandon J Carter
- Institute of Marine Sciences, University of California, Santa Cruz, California 95064, USAOcean Sciences Department, University of California, Santa Cruz, California 95064, USA
| | - Katherine M Achilles
- Institute of Marine Sciences, University of California, Santa Cruz, California 95064, USAOcean Sciences Department, University of California, Santa Cruz, California 95064, USA
| | - Jonathan P Zehr
- Institute of Marine Sciences, University of California, Santa Cruz, California 95064, USAOcean Sciences Department, University of California, Santa Cruz, California 95064, USA
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Holl CM, Montoya JP. DIAZOTROPHIC GROWTH OF THE MARINE CYANOBACTERIUM TRICHODESMIUM IMS101 IN CONTINUOUS CULTURE: EFFECTS OF GROWTH RATE ON N2 -FIXATION RATE, BIOMASS, AND C:N:P STOICHIOMETRY(1). J Phycol 2008; 44:929-937. [PMID: 27041611 DOI: 10.1111/j.1529-8817.2008.00534.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Trichodesmium N2 fixation has been studied for decades in situ and, recently, in controlled laboratory conditions; yet N2 -fixation rate estimates still vary widely. This variance has made it difficult to accurately estimate the input of new nitrogen (N) by Trichodesmium to the oligotrophic gyres of the world ocean. Field and culture studies demonstrate that trace metal limitation, phosphate availability, the preferential uptake of combined N, light intensity, and temperature may all affect N2 fixation, but the interactions between growth rate and N2 fixation have not been well characterized in this marine diazotroph. To determine the effects of growth rate on N2 fixation, we established phosphorus (P)-limited continuous cultures of Trichodesmium, which we maintained at nine steady-state growth rates ranging from 0.27 to 0.67 d(-1) . As growth rate increased, biomass (measured as particulate N) decreased, and N2 -fixation rate increased linearly. The carbon to nitrogen ratio (C:N) varied from 5.5 to 6.2, with a mean of 5.8 ± 0.2 (mean ± SD, N = 9), and decreased significantly with growth rate. The N:P ratio varied from 23.4 to 45.9, with a mean of 30.5 ± 6.6 (mean ± SD, N = 9), and remained relatively constant over the range of growth rates studied. Relative constancy of C:N:P ratios suggests a tight coupling between the uptake of these three macronutrients and steady-state growth across the range of growth rates. Our work demonstrates that growth rate must be considered when planning studies of the effects of environmental factors on N2 fixation and when modeling the impact of Trichodesmium as a source of new N to oligotrophic regions of the ocean.
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Affiliation(s)
- Carolyn M Holl
- School of Biology, Georgia Institute of Technology, Atlanta, Georgia 30332, USA
| | - Joseph P Montoya
- School of Biology, Georgia Institute of Technology, Atlanta, Georgia 30332, USA
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