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Mazur-Marzec H, Andersson AF, Błaszczyk A, Dąbek P, Górecka E, Grabski M, Jankowska K, Jurczak-Kurek A, Kaczorowska AK, Kaczorowski T, Karlson B, Kataržytė M, Kobos J, Kotlarska E, Krawczyk B, Łuczkiewicz A, Piwosz K, Rybak B, Rychert K, Sjöqvist C, Surosz W, Szymczycha B, Toruńska-Sitarz A, Węgrzyn G, Witkowski A, Węgrzyn A. Biodiversity of microorganisms in the Baltic Sea: the power of novel methods in the identification of marine microbes. FEMS Microbiol Rev 2024; 48:fuae024. [PMID: 39366767 PMCID: PMC11500664 DOI: 10.1093/femsre/fuae024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2024] [Revised: 09/21/2024] [Accepted: 10/03/2024] [Indexed: 10/06/2024] Open
Abstract
Until recently, the data on the diversity of the entire microbial community from the Baltic Sea were relatively rare and very scarce. However, modern molecular methods have provided new insights into this field with interesting results. They can be summarized as follows. (i) Although low salinity causes a reduction in the biodiversity of multicellular species relative to the populations of the North-East Atlantic, no such reduction occurs in bacterial diversity. (ii) Among cyanobacteria, the picocyanobacterial group dominates when considering gene abundance, while filamentous cyanobacteria dominate in means of biomass. (iii) The diversity of diatoms and dinoflagellates is significantly larger than described a few decades ago; however, molecular studies on these groups are still scarce. (iv) Knowledge gaps in other protistan communities are evident. (v) Salinity is the main limiting parameter of pelagic fungal community composition, while the benthic fungal diversity is shaped by water depth, salinity, and sediment C and N availability. (vi) Bacteriophages are the predominant group of viruses, while among viruses infecting eukaryotic hosts, Phycodnaviridae are the most abundant; the Baltic Sea virome is contaminated with viruses originating from urban and/or industrial habitats. These features make the Baltic Sea microbiome specific and unique among other marine environments.
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Affiliation(s)
- Hanna Mazur-Marzec
- Department of Marine Biology and Biotechnology, University of Gdansk, Al. Piłsudskiego 46, PL-81-378 Gdynia, Poland
| | - Anders F Andersson
- Department of Gene Technology, KTH Royal Institute of Technology, Science for Life Laboratory, Tomtebodavägen 23A, SE-171 65 Solna, Stockholm, Sweden
| | - Agata Błaszczyk
- Department of Marine Biology and Biotechnology, University of Gdansk, Al. Piłsudskiego 46, PL-81-378 Gdynia, Poland
| | - Przemysław Dąbek
- Institute of Marine and Environmental Sciences, University of Szczecin, Mickiewicza 16a, PL-70-383 Szczecin, Poland
| | - Ewa Górecka
- Institute of Marine and Environmental Sciences, University of Szczecin, Mickiewicza 16a, PL-70-383 Szczecin, Poland
| | - Michał Grabski
- International Centre for Cancer Vaccine Science, University of Gdansk, Kładki 24, 80-822 Gdansk, Poland
| | - Katarzyna Jankowska
- Department of Environmental Engineering Technology, Gdansk University of Technology, Narutowicza 11/12, PL-80-233 Gdansk, Poland
| | - Agata Jurczak-Kurek
- Department of Evolutionary Genetics and Biosystematics, University of Gdansk, Wita Stwosza 59, PL-80-308 Gdansk, Poland
| | - Anna K Kaczorowska
- Collection of Plasmids and Microorganisms, University of Gdansk, Wita Stwosza 59, PL-80-308 Gdansk, Poland
| | - Tadeusz Kaczorowski
- Laboratory of Extremophiles Biology, Department of Microbiology, University of Gdansk, Wita Stwosza 59, PL-80-308 Gdansk, Poland
| | - Bengt Karlson
- Swedish Meteorological and Hydrological Institute
, Research and Development, Oceanography, Göteborgseskaderns plats 3, Västra Frölunda SE-426 71, Sweden
| | - Marija Kataržytė
- Marine Research Institute, Klaipėda University, Universiteto ave. 17, LT-92294 Klaipeda, Lithuania
| | - Justyna Kobos
- Department of Marine Biology and Biotechnology, University of Gdansk, Al. Piłsudskiego 46, PL-81-378 Gdynia, Poland
| | - Ewa Kotlarska
- Institute of Oceanology, Polish Academy of Sciences, Powstańców Warszawy 55, PL-81-712 Sopot, Poland
| | - Beata Krawczyk
- Department of Biotechnology and Microbiology, Gdansk University of Technology, Narutowicza 11/12, PL-80-233 Gdansk, Poland
| | - Aneta Łuczkiewicz
- Department of Environmental Engineering Technology, Gdansk University of Technology, Narutowicza 11/12, PL-80-233 Gdansk, Poland
| | - Kasia Piwosz
- National Marine Fisheries Research Institute, Kołłątaja 1, PL-81-332 Gdynia, Poland
| | - Bartosz Rybak
- Department of Environmental Toxicology, Faculty of Health Sciences with Institute of Maritime and Tropical Medicine, Medical University of Gdansk, Dębowa 23A, PL-80-204 Gdansk, Poland
| | - Krzysztof Rychert
- Pomeranian University in Słupsk, Arciszewskiego 22a, PL-76-200 Słupsk, Poland
| | - Conny Sjöqvist
- Environmental and Marine Biology, Åbo Akademi University, Henriksgatan 2, FI-20500 Åbo, Finland
| | - Waldemar Surosz
- Department of Marine Biology and Biotechnology, University of Gdansk, Al. Piłsudskiego 46, PL-81-378 Gdynia, Poland
| | - Beata Szymczycha
- Institute of Oceanology, Polish Academy of Sciences, Powstańców Warszawy 55, PL-81-712 Sopot, Poland
| | - Anna Toruńska-Sitarz
- Department of Marine Biology and Biotechnology, University of Gdansk, Al. Piłsudskiego 46, PL-81-378 Gdynia, Poland
| | - Grzegorz Węgrzyn
- Department of Molecular Biology, University of Gdansk, Wita Stwosza 59, PL-80-308 Gdansk, Poland
| | - Andrzej Witkowski
- Institute of Marine and Environmental Sciences, University of Szczecin, Mickiewicza 16a, PL-70-383 Szczecin, Poland
| | - Alicja Węgrzyn
- University Center for Applied and Interdisciplinary Research, University of Gdansk, Kładki 24, 80-822 Gdansk, Poland
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Xie K, Wang Y, Xue J, Wang H, Lai A, Mao Z, Li H, Lauridsen TL, Li B, Wu QL. Microbial nitrogen cycling in Microcystis colonies and its contribution to nitrogen removal in eutrophic Lake Taihu, China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 954:176323. [PMID: 39299336 DOI: 10.1016/j.scitotenv.2024.176323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2024] [Revised: 09/13/2024] [Accepted: 09/14/2024] [Indexed: 09/22/2024]
Abstract
Cyanobacterial blooms induced by excessive loadings of nitrogen (N) and other nutrients are a severe ecological problem in aquatic ecosystems. Previous studies of N removal have primarily focused on sediment-water interface, yet the role of cyanobacterial colonies has recently been attracting more research attention. In this study, N cycling processes were quantified for cyanobacterial colonies (primarily Microcystis colonies) and their contribution to N removal was estimated for a large, shallow eutrophic lake in China, Lake Taihu. Various N cycling processes were determined via stable 15N isotope, together with 16S rRNA gene sequencing and quantitative microbial element cycling (QMEC) chip. Denitrification was found to be the most prominent process, estimated to be 36.63, 9.85, 3.35, and 3.15 times higher than dissimilatory nitrate reduction to ammonium (DNRA), nitrification, ammonium (NH4+) uptake and nitrate (NO3-) uptake rates, respectively. Denitrifiers accounted for a large part of the bacterial taxa (35.50 ± 24.65%), and the nirS gene was the most abundant among N cycling-related genes, with (2.54 ± 0.51) × 109 copies g-1Microcystis colonies. A field investigation revealed a positive correlation between the potential denitrification rate and the Chl-a concentration (mostly derived from Microcystis colonies). Based on a multiple stepwise regression model and historical data from 2007 to 2015 for Lake Taihu, the total amount of N removed via denitrification by Microcystis colonies was estimated at 171.72 ± 49.74 t yr-1; this suggests that Microcystis colonies have played an important role in N removal in Lake Taihu since the drinking water crisis in 2007. Overall, this study revealed the importance of denitrification within Microcystis colonies for N removal in eutrophic lakes, like Lake Taihu.
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Affiliation(s)
- Ke Xie
- Key Laboratory of Lake and Watershed Science for Water Security, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China; State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China; University of Chinese Academy of Sciences, Beijing 100039, China
| | - Yujing Wang
- Key Laboratory of Lake and Watershed Science for Water Security, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China; State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China
| | - Jingya Xue
- School of Geographical Sciences, Nanjing Normal University, Nanjing 210023, China
| | - Hongwei Wang
- Key Laboratory of Lake and Watershed Science for Water Security, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China; State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China; University of Chinese Academy of Sciences, Beijing 100039, China
| | - Anxing Lai
- Key Laboratory of Lake and Watershed Science for Water Security, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China; State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China; University of Chinese Academy of Sciences, Beijing 100039, China
| | - Zhengdu Mao
- Center for Evolution and Conservation Biology, Southern Marine Sciences and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 511458, China
| | - Huabing Li
- Key Laboratory of Lake and Watershed Science for Water Security, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China; State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China
| | - Torben L Lauridsen
- Sino-Danish Center for Science and Education, University of Chinese Academy of Sciences, Beijing 100039, China; Department of Ecoscience and Centre for Water Technology (WATEC), Aarhus University, C.F. Møllers Allé 3, 8000 Aarhus C, Denmark
| | - Biao Li
- Key Laboratory of Lake and Watershed Science for Water Security, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China; State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China.
| | - Qinglong L Wu
- Key Laboratory of Lake and Watershed Science for Water Security, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China; State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China; Center for Evolution and Conservation Biology, Southern Marine Sciences and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 511458, China; Sino-Danish Center for Science and Education, University of Chinese Academy of Sciences, Beijing 100039, China; The Fuxianhu Station of Plateau Deep Lake Research, Chinese Academy of Sciences, Yuxi 653100, China.
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Deng D, Meng H, Ma Y, Guo Y, Wang Z, He H, Xie W, Liu JE, Zhang L. The cumulative impact of temperature and nitrogen availability on the potential nitrogen fixation and extracellular polymeric substances secretion by Dolichospermum. HARMFUL ALGAE 2024; 135:102633. [PMID: 38830715 DOI: 10.1016/j.hal.2024.102633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Revised: 04/02/2024] [Accepted: 04/24/2024] [Indexed: 06/05/2024]
Abstract
Nitrogen-fixing cyanobacteria not only cause severe blooms but also play an important role in the nitrogen input processes of lakes. The production of extracellular polymeric substances (EPS) and the ability to fix nitrogen from the atmosphere provide nitrogen-fixing cyanobacteria with a competitive advantage over other organisms. Temperature and nitrogen availability are key environmental factors in regulating the growth of cyanobacteria. In this study, Dolichospermum (formerly known as Anabaena) was cultivated at three different temperatures (10 °C, 20 °C, and 30 °C) to examine the impact of temperature and nitrogen availability on nitrogen fixation capacity and the release of EPS. Initially, confocal laser scanning microscopy (CLSM) and the quantification of heterocysts at different temperatures revealed that lower temperatures (10 °C) hindered the differentiation of heterocysts under nitrogen-deprived conditions. Additionally, while heterocysts inhibited the photosynthetic activity of Dolichospermum, the secretion of EPS was notably affected by nitrogen limitation, particularly at 30 °C. Finally, real-time quantitative polymerase chain reaction (qPCR) was used to measure the expression of nitrogen-utilizing genes (ntcA and nifH) and EPS synthesis-related genes (wzb and wzc). The results indicated that under nitrogen-deprived conditions, the expression of each gene was upregulated, and there was a significant correlation between the upregulation of nitrogen-utilizing and EPS synthesis genes (P < 0.05). Our findings suggested that Dolichospermum responded to temperature variation by affecting the formation of heterocysts, impacting its potential nitrogen fixation capacity. Furthermore, the quantity of EPS released was more influenced by nitrogen availability than temperature. This research enhances our comprehension of interconnections between nitrogen deprivation and EPS production under the different temperatures.
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Affiliation(s)
- Dailan Deng
- School of Environment, Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application, Nanjing Normal University, Nanjing 210023, PR China; Jiangsu Engineering Lab of Water and Soil Eco-remediation, Nanjing 210023, China
| | - Han Meng
- School of Environment, Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application, Nanjing Normal University, Nanjing 210023, PR China; Jiangsu Engineering Lab of Water and Soil Eco-remediation, Nanjing 210023, China
| | - You Ma
- School of Environment, Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application, Nanjing Normal University, Nanjing 210023, PR China; Jiangsu Engineering Lab of Water and Soil Eco-remediation, Nanjing 210023, China
| | - Yongqi Guo
- School of Environment, Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application, Nanjing Normal University, Nanjing 210023, PR China; Jiangsu Engineering Lab of Water and Soil Eco-remediation, Nanjing 210023, China
| | - Zixuan Wang
- School of Environment, Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application, Nanjing Normal University, Nanjing 210023, PR China; Jiangsu Engineering Lab of Water and Soil Eco-remediation, Nanjing 210023, China
| | - Huan He
- School of Environment, Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application, Nanjing Normal University, Nanjing 210023, PR China; Jiangsu Engineering Lab of Water and Soil Eco-remediation, Nanjing 210023, China
| | - Wenming Xie
- School of Environment, Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application, Nanjing Normal University, Nanjing 210023, PR China; Jiangsu Engineering Lab of Water and Soil Eco-remediation, Nanjing 210023, China
| | - Jin-E Liu
- School of Environment, Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application, Nanjing Normal University, Nanjing 210023, PR China; Jiangsu Engineering Lab of Water and Soil Eco-remediation, Nanjing 210023, China.
| | - Limin Zhang
- School of Environment, Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application, Nanjing Normal University, Nanjing 210023, PR China; Green Economy Development Institute, Nanjing University of Finance and Economics, Nanjing 210023, PR China
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Efremova J, Mazzella V, Mirasole A, Teixidó N, Núñez-Pons L. Divergent morphological and microbiome strategies of two neighbor sponges to cope with low pH in Mediterranean CO 2 vents. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 916:170171. [PMID: 38246375 DOI: 10.1016/j.scitotenv.2024.170171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Revised: 12/23/2023] [Accepted: 01/12/2024] [Indexed: 01/23/2024]
Abstract
Ocean Acidification (OA) profoundly impacts marine biochemistry, resulting in a net loss of biodiversity. Porifera are often forecasted as winner taxa, yet the strategies to cope with OA can vary and may generate diverse fitness status. In this study, microbial shifts based on the V3-V4 16S rRNA gene marker were compared across neighboring Chondrosia reniformis sponges with high microbial abundance (HMA), and Spirastrella cunctatrix with low microbial abundance (LMA) microbiomes. Sponge holobionts co-occurred in a CO2 vent system with low pH (pHT ~ 7.65), and a control site with Ambient pH (pHT ~ 8.05) off Ischia Island, representing natural analogues to study future OA, and species' responses in the face of global environmental change. Microbial diversity and composition varied in both species across sites, yet at different levels. Increased numbers of core taxa were detected in S. cunctatrix, and a more diverse and flexible core microbiome was reported in C. reniformis under OA. Vent S. cunctatrix showed morphological impairment, along with signs of putative stress-induced dysbiosis, manifested by: 1) increases in alpha diversity, 2) shifts from sponge related microbes towards seawater microbes, and 3) high dysbiosis scores. Chondrosia reniformis in lieu, showed no morphological variation, low dysbiosis scores, and experienced a reduction in alpha diversity and less number of core taxa in vent specimens. Therefore, C. reniformis is hypothesized to maintain an state of normobiosis and acclimatize to OA, thanks to a more diverse, and likely metabolically versatile microbiome. A consortium of differentially abundant microbes was identified associated to either vent or control sponges, and chiefly related to carbon, nitrogen and sulfur-metabolisms for nutrient cycling and vitamin production, as well as probiotic symbionts in C. reniformis. Diversified symbiont associates supporting functional convergence could be the key behind resilience towards OA, yet specific acclimatization traits should be further investigated.
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Affiliation(s)
- Jana Efremova
- Department of Integrative Marine Ecology (EMI), Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Naples, Italy; NBFC, National Biodiversity Future Center, Piazza Marina 61, 90133 Palermo, Italy.
| | - Valerio Mazzella
- NBFC, National Biodiversity Future Center, Piazza Marina 61, 90133 Palermo, Italy; Stazione Zoologica Anton Dohrn, National Institute of Marine Biology, Ecology and Biotechnology, Ischia Marine Centre, Ischia 80077, Naples, Italy.
| | - Alice Mirasole
- Stazione Zoologica Anton Dohrn, National Institute of Marine Biology, Ecology and Biotechnology, Ischia Marine Centre, Ischia 80077, Naples, Italy.
| | - Núria Teixidó
- NBFC, National Biodiversity Future Center, Piazza Marina 61, 90133 Palermo, Italy; Stazione Zoologica Anton Dohrn, National Institute of Marine Biology, Ecology and Biotechnology, Ischia Marine Centre, Ischia 80077, Naples, Italy; Laboratoire d'Océanographie de Villefranche, Sorbonne Université, CNRS, Villefranche-sur-mer, France.
| | - Laura Núñez-Pons
- Department of Integrative Marine Ecology (EMI), Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Naples, Italy; NBFC, National Biodiversity Future Center, Piazza Marina 61, 90133 Palermo, Italy.
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Bauer F, Wolfschlaeger I, Geist J, Fastner J, Schmalz CW, Raeder U. Occurrence, Distribution and Toxins of Benthic Cyanobacteria in German Lakes. TOXICS 2023; 11:643. [PMID: 37624149 PMCID: PMC10458227 DOI: 10.3390/toxics11080643] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Revised: 07/20/2023] [Accepted: 07/21/2023] [Indexed: 08/26/2023]
Abstract
Cyanobacteria are favored by climate change and global warming; however, to date, most research and monitoring programs have focused on planktic cyanobacteria. Benthic cyanobacteria blooms also increase and pose a risk to animal and human health; however, there is limited knowledge of their occurrence, distribution and the toxins involved, especially in relation to their planktic conspecifics. Therefore, we analyzed the benthic and planktic life forms of cyanobacterial communities in 34 lakes in Germany, including a monitoring of cyanotoxins. Community analyses were based on microscopic examination and Illumina sequencing of the 16S rRNA gene. The analyses of cyanotoxins were carried out using LC-MS/MS and ELISA. Observed benthic mats containing cyanobacteria consisted mainly of Nostocales and Oscillatoriales, being present in 35% of the lakes. Anatoxin was the most abundant cyanotoxin in the benthic samples, reaching maximum concentrations of 45,000 µg/L, whereas microcystin was the predominate cyanotoxin in the open-water samples, reaching concentrations of up to 18,000 µg/L. Based on the results, specific lakes at risk of toxic cyanobacteria could be identified. Our findings suggest that monitoring of benthic cyanobacteria and their toxins should receive greater attention, ideally complementing existing open-water sampling programs with little additional effort.
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Affiliation(s)
- Franziska Bauer
- Aquatic Systems Biology Unit, Limnological Research Station Iffeldorf, Technical University of Munich, Hofmark 1–3, 82393 Iffeldorf, Germany (U.R.)
| | - Immanuel Wolfschlaeger
- Aquatic Systems Biology Unit, Limnological Research Station Iffeldorf, Technical University of Munich, Hofmark 1–3, 82393 Iffeldorf, Germany (U.R.)
| | - Juergen Geist
- Aquatic Systems Biology Unit, Limnological Research Station Iffeldorf, Technical University of Munich, Hofmark 1–3, 82393 Iffeldorf, Germany (U.R.)
| | - Jutta Fastner
- German Environment Agency, Schichauweg 58, 12307 Berlin, Germany
| | - Carina Wiena Schmalz
- Aquatic Systems Biology Unit, Limnological Research Station Iffeldorf, Technical University of Munich, Hofmark 1–3, 82393 Iffeldorf, Germany (U.R.)
| | - Uta Raeder
- Aquatic Systems Biology Unit, Limnological Research Station Iffeldorf, Technical University of Munich, Hofmark 1–3, 82393 Iffeldorf, Germany (U.R.)
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Phytoplankton Community Response to Environmental Factors along a Salinity Gradient in a Seagoing River, Tianjin, China. Microorganisms 2022; 11:microorganisms11010075. [PMID: 36677367 PMCID: PMC9864511 DOI: 10.3390/microorganisms11010075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 12/20/2022] [Accepted: 12/21/2022] [Indexed: 12/29/2022] Open
Abstract
A river-estuary ecosystem usually features a distinct salinity gradient and a complex water environment, so it is enormously valuable to study the response mechanism of living organisms to multiple abiotic factors under salinity stress. Phytoplankton, as an important part of aquatic microorganisms, has always been of concern for its crucial place in the aquatic ecosystem. In this study, phytoplankton data and 18 abiotic factors collected from 15 stations in Duliujian River, a seagoing river, were investigated in different seasons. The results showed that the river studied was of a Cyanophyta-dominant type. Salinity (SAL) was the key control factor for phytoplankton species richness, while water temperature (WT) was critical not only for species richness, but also community diversity, and the abundance and biomass of dominant species. Apart from WT, the abundance and biomass of dominant species were also driven by total nitrogen (TN), nitrate (NO3-), pH, and water transparency (SD). Moreover, total dissolved phosphorus (TDP), pH, and chemical oxygen demand (COD) were crucial for community diversity and evenness. The bloom of dominant species positively associated with TDP led to lower diversity and evenness in autumn. In addition, when available nitrogen was limited, Pseudoanabaena sp. could obtain a competitive advantage through the N2 fixation function. Increased available nitrogen concentration could favor the abundance of Chlorella vulgaris to resist the negative effect of WT. The results show that Oscillatoria limosa could serve as an indicator of organic contamination, and nutrient-concentration control must be effective to inhibit Microcystis bloom. This could help managers to formulate conservation measures.
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Liepina-Leimane I, Barda I, Jurgensone I, Labucis A, Suhareva N, Kozlova V, Maderniece A, Aigars J. Seasonal dynamic of diazotrophic activity and environmental variables affecting it in the Gulf of Riga, Baltic Sea. FEMS Microbiol Ecol 2022; 98:6819948. [PMID: 36354101 PMCID: PMC9712029 DOI: 10.1093/femsec/fiac132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 10/30/2022] [Accepted: 11/07/2022] [Indexed: 11/11/2022] Open
Abstract
The semi-enclosed Baltic Sea experiences regular summer blooms of diazotrophic cyanobacteria. Previously, it has been conclusively demonstrated that in open nitrogen-limited parts of the Baltic Sea, cyanobacteria successfully fix atmospheric N2. At the same time, diazotrophic activity is still poorly understood in Baltic Sea sub-regions where nitrogen and phosphorus are co-limiting primary production. To address this gap in research, we used the15 N tracer method for in situ incubations and measured the N2-fixation rate of heterocyst-forming cyanobacteria and picocyanobacteria in the Gulf of Riga, Baltic Sea, from April to September. Physicochemical variables and phytoplankton community composition were also determined. Our results show that the dominant species of cyanobacteria for this region (Aphanizomenon flosaquae) was present in the phytoplankton community during most of the study period. We also establish that the N2-fixation rate has a strong correlation with the proportion of A. flosaquae biomass containing heterocysts (r = 0.80). Our findings highlight the importance of a heterocyst-focused approach for an accurate diazotrophic activity evaluation that is one of the foundations for future management and protection of the Baltic Sea.
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Affiliation(s)
| | - Ieva Barda
- Latvian Institute of Aquatic Ecology, Agency of Daugavpils University, Voleru Street 4, Riga, Latvia, LV-1007
| | - Iveta Jurgensone
- Latvian Institute of Aquatic Ecology, Agency of Daugavpils University, Voleru Street 4, Riga, Latvia, LV-1007
| | - Atis Labucis
- Latvian Institute of Aquatic Ecology, Agency of Daugavpils University, Voleru Street 4, Riga, Latvia, LV-1007
| | - Natalija Suhareva
- Latvian Institute of Aquatic Ecology, Agency of Daugavpils University, Voleru Street 4, Riga, Latvia, LV-1007
| | - Vendija Kozlova
- Latvian Institute of Aquatic Ecology, Agency of Daugavpils University, Voleru Street 4, Riga, Latvia, LV-1007
| | - Agita Maderniece
- Latvian Institute of Aquatic Ecology, Agency of Daugavpils University, Voleru Street 4, Riga, Latvia, LV-1007
| | - Juris Aigars
- Latvian Institute of Aquatic Ecology, Agency of Daugavpils University, Voleru Street 4, Riga, Latvia, LV-1007
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Brenes-Guillén L, Vidaurre-Barahona D, Avilés-Vargas L, Castro-Gutierrez V, Gómez-Ramírez E, González-Sánchez K, Mora-López M, Umaña-Villalobos G, Uribe-Lorío L, Hassard F. First insights into the prokaryotic community structure of Lake Cote, Costa Rica: Influence on nutrient cycling. Front Microbiol 2022; 13:941897. [PMID: 36262328 PMCID: PMC9574093 DOI: 10.3389/fmicb.2022.941897] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Accepted: 08/29/2022] [Indexed: 11/13/2022] Open
Abstract
Prokaryotic diversity in lakes has been studied for many years mainly focusing on community structure and how the bacterial assemblages are driven by physicochemical conditions such as temperature, oxygen, and nutrients. However, little is known about how the composition and function of the prokaryotic community changes upon lake stratification. To elucidate this, we studied Lake Cote in Costa Rica determining prokaryotic diversity and community structure in conjunction with physicochemistry along vertical gradients during stratification and mixing periods. Of the parameters measured, ammonium, oxygen, and temperature, in that order, were the main determinants driving the variability in the prokaryotic community structure of the lake. Distinct stratification of Lake Cote occurred (March 2018) and the community diversity was compared to a period of complete mixing (March 2019). The microbial community analysis indicated that stratification significantly altered the bacterial composition in the epi-meta- and hypolimnion. During stratification, the Deltaproteobacteria, Chloroflexi, Bacteroidetes, Nitrospirae, and Euryarchaeota were dominant in the hypolimnion yet largely absent in surface layers. Among these taxa, strict or facultative anaerobic bacteria were likely contributing to the lake nitrogen biogeochemical cycling, consistent with measurements of inorganic nitrogen measurements and microbial functional abundance predictions. In general, during both sampling events, a higher abundance of Alphaproteobacteria, Betaproteobacteria, Actinobacteria, and Cyanobacteria was found in the oxygenated layers. Lake Cote had a unique bacterial diversity, with 80% of Amplicon Sequence Variant (ASV) recovered similar to unclassified/uncultured strains and exhibits archetypal shallow lake physicochemical but not microbial fluctuations worthy of further investigation. This study provides an example of lake hydrodynamics impacts to microbial community and their function in Central American lakes with implications for other shallow, upland, and oligotrophic lake systems.
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Affiliation(s)
- Laura Brenes-Guillén
- Cellular and Molecular Biology Research Center, University of Costa Rica, San José, Costa Rica
| | | | - Lidia Avilés-Vargas
- Research Center in Sciences of the Sea and Limnology, University of Costa Rica, San José, Costa Rica
| | | | - Eddy Gómez-Ramírez
- Research Center in Sciences of the Sea and Limnology, University of Costa Rica, San José, Costa Rica
| | - Kaylen González-Sánchez
- Research Center in Sciences of the Sea and Limnology, University of Costa Rica, San José, Costa Rica
| | - Marielos Mora-López
- Cellular and Molecular Biology Research Center, University of Costa Rica, San José, Costa Rica
| | - Gerardo Umaña-Villalobos
- Research Center in Sciences of the Sea and Limnology, University of Costa Rica, San José, Costa Rica
| | - Lorena Uribe-Lorío
- Cellular and Molecular Biology Research Center, University of Costa Rica, San José, Costa Rica
| | - Francis Hassard
- Cranfield Water Science Institute, Cranfield University, Cranfield, United Kingdom
- Institute for Nanotechnology and Water Sustainability, University of South Africa, Johannesburg, South Africa
- *Correspondence: Francis Hassard,
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9
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Karlson B, Arneborg L, Johansson J, Linders J, Liu Y, Olofsson M. A suggested climate service for cyanobacteria blooms in the Baltic Sea - Comparing three monitoring methods. HARMFUL ALGAE 2022; 118:102291. [PMID: 36195413 PMCID: PMC9559175 DOI: 10.1016/j.hal.2022.102291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 07/07/2022] [Accepted: 07/11/2022] [Indexed: 05/06/2023]
Abstract
Dense blooms of filamentous cyanobacteria are recurrent phenomena in the Baltic Sea, with occasional negative effects on the surrounding ecosystem, as well as on tourism, human health, aquaculture, and fisheries. Establishing a climate service is therefore suggested; including multi-method observations of cyanobacteria biomass, biodiversity, and biogeography, in correspondence to biotic and abiotic factors. Three different approaches were compared for determination of spatial and temporal variability and trends of the blooms; 1) microscopy-based long-term data, 2) satellite remote sensing, and 3) phycocyanin fluorescence mounted on a merchant vessel. Firstly, microscopy-based data on cyanobacteria biomass from the period 2000-2020 showed that the toxin producing genus Nodularia and non-toxic Aphanizomenon both had summer means of 15 µg C L-1, while Dolichospermum was less dominant with a mean of 8 µg C L-1. Some years also the Kattegat was affected by cyanobacteria blooms, likely transported here by ocean currents. Secondly, the satellite remote sensing time series for the period 2002-2020 indicated that near surface blooms were most frequent in the Northern Baltic Proper and that near surface blooms have increased in the Bothnian Sea, starting later in the season than in the Baltic Proper. The largest extents (i.e., total area covered) were observed in 2005, 2008, and 2018. Thirdly, phycocyanin fluorescence from a flow through sensor mounted on a merchant vessel was used as a proxy for cyanobacteria biomass and correlated to cyanobacteria biomass estimated by microscopy. However, the satellite remote sensing data on surface accumulations showed little resemblance to the data on cyanobacteria biomass based on water sampling and microscopy, interpreted as an effect of methods. Sensors on satellites mainly detect surface accumulations of cyanobacteria while the microscopy data was based on samples 0-10 m, thereby comprising a larger community. Data from satellite remote sensing of cyanobacteria was correlated to the phycocyanin fluorescence indicating that similar bio-optical properties are observed. Finally, results from a downscaled ocean climate model (NEMONordic) were used to produce future scenarios for temperature and salinity, which directly affects cyanobacteria blooms in the Baltic Sea, supposedly by increasing in abundance and change in species composition. Short-term forecasts can be used together with observations for early warning of cyanobacteria blooms, and we suggest an internationally coordinated cyanobacteria observation and warning system for the Baltic Sea area.
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Affiliation(s)
- Bengt Karlson
- Research and Development, Oceanography, Swedish Meteorological and Hydrological Institute, Västra Frölunda, Sweden.
| | - Lars Arneborg
- Research and Development, Oceanography, Swedish Meteorological and Hydrological Institute, Västra Frölunda, Sweden
| | - Johannes Johansson
- Oceanographic Services, Swedish Meteorological and Hydrological Institute, Västra Frölunda, Sweden
| | - Johanna Linders
- Oceanographic Services, Swedish Meteorological and Hydrological Institute, Västra Frölunda, Sweden
| | - Ye Liu
- Research and Development, Oceanography, Swedish Meteorological and Hydrological Institute, Västra Frölunda, Sweden
| | - Malin Olofsson
- Research and Development, Oceanography, Swedish Meteorological and Hydrological Institute, Västra Frölunda, Sweden; Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Uppsala, Sweden
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10
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Liu J, Wang X, Liu J, Liu X, Zhang XH, Liu J. Comparison of assembly process and co-occurrence pattern between planktonic and benthic microbial communities in the Bohai Sea. Front Microbiol 2022; 13:1003623. [PMID: 36386657 PMCID: PMC9641972 DOI: 10.3389/fmicb.2022.1003623] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Accepted: 09/05/2022] [Indexed: 10/10/2023] Open
Abstract
Unraveling the mechanisms structuring microbial community is a central goal in microbial ecology, but a detailed understanding of how community assembly processes relate to living habitats is still lacking. Here, via 16S rRNA gene amplicon sequencing, we investigated the assembly process of microbial communities in different habitats [water verse sediment, free-living (FL) verse particle-associated (PA)] and their impacts on the inter-taxa association patterns in the coastal Bohai Sea, China. The results showed clear differences in the composition and diversity of microbial communities among habitats, with greater dissimilarities between water column and sediment than between FL and PA communities. The microbial community assembly was dominated by dispersal limitation, ecological drift, and homogeneous selection, but their relative importance varied in different habitats. The planktonic communities were mainly shaped by dispersal limitation and ecological drift, whereas homogeneous selection played a more important role in structuring the benthic communities. Furthermore, the assembly mechanisms differed between FL and PA communities, especially in the bottom water with a greater effect of ecological drift and dispersal limitation on the FL and PA fractions, respectively. Linking assembly process to co-occurrence pattern showed that the relative contribution of deterministic processes (mainly homogeneous selection) increased under closer co-occurrence relationships. By contrast, stochastic processes exerted a higher effect when there were less inter-taxa connections. Overall, our findings demonstrate contrasting ecological processes underpinning microbial community distribution in different habitats including different lifestyles, which indicate complex microbial dynamic patterns in coastal systems with high anthropogenic perturbations.
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Affiliation(s)
- Jinmei Liu
- Frontiers Science Center for Deep Ocean Multispheres and Earth System and College of Marine Life Sciences, Ocean University of China, Qingdao, China
| | - Xiaolei Wang
- Frontiers Science Center for Deep Ocean Multispheres and Earth System and College of Marine Life Sciences, Ocean University of China, Qingdao, China
| | - Jiao Liu
- Frontiers Science Center for Deep Ocean Multispheres and Earth System and College of Marine Life Sciences, Ocean University of China, Qingdao, China
| | - Xiaoyue Liu
- Frontiers Science Center for Deep Ocean Multispheres and Earth System and College of Marine Life Sciences, Ocean University of China, Qingdao, China
| | - Xiao-Hua Zhang
- Frontiers Science Center for Deep Ocean Multispheres and Earth System and College of Marine Life Sciences, Ocean University of China, Qingdao, China
- Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
- Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao, China
| | - Jiwen Liu
- Frontiers Science Center for Deep Ocean Multispheres and Earth System and College of Marine Life Sciences, Ocean University of China, Qingdao, China
- Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
- Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao, China
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11
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Bano A, Waqar A, Khan A, Tariq H. Phytostimulants in sustainable agriculture. FRONTIERS IN SUSTAINABLE FOOD SYSTEMS 2022. [DOI: 10.3389/fsufs.2022.801788] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The consistent use of synthetic fertilizers and chemicals in traditional agriculture has not only compromised the fragile agroecosystems but has also adversely affected human, aquatic, and terrestrial life. The use of phytostimulants is an alternative eco-friendly approach that eliminates ecosystem disruption while maintaining agricultural productivity. Phytostimulants include living entities and materials, such as microorganisms and nanomaterials, which when applied to plants or to the rhizosphere, stimulate plant growth and induce tolerance to plants against biotic and abiotic stresses. In this review, we focus on plant growth-promoting rhizobacteria (PGPR), beneficial fungi, such as arbuscular mycorrhizal fungi (AMF) and plant growth-promoting fungi (PGPF), actinomycetes, cyanobacteria, azolla, and lichens, and their potential benefits in the crop improvement, and mitigation of abiotic and biotic stresses either alone or in combination. PGPR, AMF, and PGPF are plant beneficial microbes that can release phytohormones, such as indole acetic acid (IAA), gibberellic acid (GA), and cytokinins, promoting plant growth and improving soil health, and in addition, they also produce many secondary metabolites, antibiotics, and antioxidant compounds and help to combat biotic and abiotic stresses. Their ability to act as phytostimulator and a supplement of inorganic fertilizers is considered promising in practicing sustainable agriculture and organic farming. Glomalin is a proteinaceous product, produced by AMF, involved in soil aggregation and elevation of soil water holding capacity under stressed and unstressed conditions. The negative effects of continuous cropping can be mitigated by AMF biofertilization. The synergistic effects of PGPR and PGPF may be more effective. The mechanisms of control exercised by PGPF either direct or indirect to suppress plant diseases viz. by competing for space and nutrients, mycoparasitism, antibiosis, mycovirus-mediated cross-protection, and induced systemic resistance (ISR) have been discussed. The emerging role of cyanobacterial metabolites and the implication of nanofertilizers have been highlighted in sustainable agriculture.
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12
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Antosiak A, Šulčius S, Malec P, Tokodi N, Łobodzińska A, Dziga D. Cyanophage infections reduce photosynthetic activity and expression of CO 2 fixation genes in the freshwater bloom-forming cyanobacterium Aphanizomenon flos-aquae. HARMFUL ALGAE 2022; 116:102215. [PMID: 35710200 DOI: 10.1016/j.hal.2022.102215] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 02/20/2022] [Accepted: 02/25/2022] [Indexed: 06/15/2023]
Abstract
Cyanobacteria play a significant role in ecosystem functioning as photosynthetic and CO2 fixing microorganisms. Whether and to what extent cyanophages alter these carbon and energy cycles in their cyanobacterial hosts is still poorly understood. In this study, we investigated changes in photosynthetic activity (PSII), expression of genes associated with the light phase of photosynthesis (psbA, petA, ndhK) and carbon metabolism (rbcL, zwf) as well as intracellular ATP and NADHP concentrations in freshwater bloom-forming filamentous cyanobacterium Aphanizomenon flos-aquae infected by cyanophage vB_AphaS-CL131. We found that PSII activity and expression level of rbcL genes, indicating potential for CO2 fixation, had decreased in response to cyanophage adsorption and DNA injection. During the period of viral DNA replication and assembly, PSII performance and gene expression remained at this decreased level and did not change significantly, indicating lack of transcriptional shutdown by the cyanophage. Combined, these observations suggest that although there is little to no interference between cyanophage DNA replication, host transcription and cellular metabolism, A. flos-aquae underwent a physiological state-shift toward lower efficiency of carbon and energy cycling. This further suggest potential cascading effect for co-occurring non-infected members of the microbial community.
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Affiliation(s)
- Adam Antosiak
- Laboratory of Metabolomics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30387 Krakow, Poland.
| | - Sigitas Šulčius
- Laboratory of Algology and Microbial Ecology, Nature Research Centre, Akademijos str. 2, 08412 Vilnius, Lithuania.
| | - Przemysław Malec
- Department of Plant Physiology and Biochemistry, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30387 Krakow, Poland.
| | - Nada Tokodi
- Laboratory of Metabolomics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30387 Krakow, Poland; Department of Biology and Ecology, University of Novi Sad, Faculty of Sciences, Trg Dositeja Obradovića 3, 21000 Novi Sad, Serbia.
| | - Antonia Łobodzińska
- Laboratory of Metabolomics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30387 Krakow, Poland.
| | - Dariusz Dziga
- Laboratory of Metabolomics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30387 Krakow, Poland.
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13
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Polerecky L, Eichner M, Masuda T, Zavřel T, Rabouille S, Campbell DA, Halsey K. Calculation and Interpretation of Substrate Assimilation Rates in Microbial Cells Based on Isotopic Composition Data Obtained by nanoSIMS. Front Microbiol 2021; 12:621634. [PMID: 34917040 PMCID: PMC8670600 DOI: 10.3389/fmicb.2021.621634] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Accepted: 11/08/2021] [Indexed: 11/17/2022] Open
Abstract
Stable isotope probing (SIP) combined with nano-scale secondary ion mass spectrometry (nanoSIMS) is a powerful approach to quantify assimilation rates of elements such as C and N into individual microbial cells. Here, we use mathematical modeling to investigate how the derived rate estimates depend on the model used to describe substrate assimilation by a cell during a SIP incubation. We show that the most commonly used model, which is based on the simplifying assumptions of linearly increasing biomass of individual cells over time and no cell division, can yield underestimated assimilation rates when compared to rates derived from a model that accounts for cell division. This difference occurs because the isotopic labeling of a dividing cell increases more rapidly over time compared to a non-dividing cell and becomes more pronounced as the labeling increases above a threshold value that depends on the cell cycle stage of the measured cell. Based on the modeling results, we present formulae for estimating assimilation rates in cells and discuss their underlying assumptions, conditions of applicability, and implications for the interpretation of intercellular variability in assimilation rates derived from nanoSIMS data, including the impacts of storage inclusion metabolism. We offer the formulae as a Matlab script to facilitate rapid data evaluation by nanoSIMS users.
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Affiliation(s)
- Lubos Polerecky
- Department of Earth Sciences, Utrecht University, Utrecht, Netherlands
| | - Meri Eichner
- Institute of Microbiology, Czech Academy of Sciences, Centre Algatech, Třeboň, Czechia
| | - Takako Masuda
- Institute of Microbiology, Czech Academy of Sciences, Centre Algatech, Třeboň, Czechia
| | - Tomáš Zavřel
- Global Change Research Institute, Czech Academy of Sciences, Brno, Czechia
| | - Sophie Rabouille
- Sorbonne Université, CNRS, Laboratoire d'Océanographie de Villefranche, LOV, Villefranche-sur-mer, France.,Sorbonne Université, CNRS, Laboratoire d'Océanographie Microbienne, LOMIC, Banyuls-sur-mer, France
| | | | - Kimberly Halsey
- Department of Microbiology, Oregon State University, Corvallis, OR, United States
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14
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Cryptic Constituents: The Paradox of High Flux–Low Concentration Components of Aquatic Ecosystems. WATER 2021. [DOI: 10.3390/w13162301] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The interface between terrestrial ecosystems and inland waters is an important link in the global carbon cycle. However, the extent to which allochthonous organic matter entering freshwater systems plays a major role in microbial and higher-trophic-level processes is under debate. Human perturbations can alter fluxes of terrestrial carbon to aquatic environments in complex ways. The biomass and production of aquatic microbes are traditionally thought to be resource limited via stoichiometric constraints such as nutrient ratios or the carbon standing stock at a given timepoint. Low concentrations of a particular constituent, however, can be strong evidence of its importance in food webs. High fluxes of a constituent are often associated with low concentrations due to high uptake rates, particularly in aquatic food webs. A focus on biomass rather than turnover can lead investigators to misconstrue dissolved organic carbon use by bacteria. By combining tracer methods with mass balance calculations, we reveal hidden patterns in aquatic ecosystems that emphasize fluxes, turnover rates, and molecular interactions. We suggest that this approach will improve forecasts of aquatic ecosystem responses to warming or altered nitrogen usage.
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15
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Single-Cell Measurements of Fixation and Intercellular Exchange of C and N in the Filaments of the Heterocyst-Forming Cyanobacterium Anabaena sp. Strain PCC 7120. mBio 2021; 12:e0131421. [PMID: 34399619 PMCID: PMC8406292 DOI: 10.1128/mbio.01314-21] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Under diazotrophic conditions, the model filamentous, heterocyst-forming cyanobacterium Anabaena sp. strain PCC 7120 develops a metabolic strategy based on the physical separation of the processes of oxygenic photosynthesis, in vegetative cells, and N2 fixation, in heterocysts. This strategy requires the exchange of carbon and nitrogen metabolites and their distribution along the filaments, which takes place through molecular diffusion via septal junctions involving FraCD proteins. Here, Anabaena was incubated in a time course (up to 20 h) with [13C]bicarbonate and 15N2 and analyzed by secondary ion mass spectrometry imaging (SIMS) (large-geometry SIMS [LG-SIMS] and NanoSIMS) to quantify C and N assimilation and distribution in the filaments. The 13C/12C and 15N/14N ratios measured in wild-type filaments showed a general increase with time. The enrichment was relatively homogeneous in vegetative cells along individual filaments, while it was reduced in heterocysts. Heterocysts, however, accumulated recently fixed N at their poles, in which the cyanophycin plug [multi-l-arginyl-poly(l-aspartic acid)] is located. In contrast to the rather homogeneous label found along stretches of vegetative cells, 13C/12C and 15N/14N ratios were significantly different between filaments both at the same and different time points, showing high variability in metabolic states. A fraC fraD mutant did not fix N2, and the 13C/12C ratio was homogeneous along the filament, including the heterocyst in contrast to the wild type. Our results show the consumption of reduced C in the heterocysts associated with the fixation and export of fixed N and present an unpredicted heterogeneity of cellular metabolic activity in different filaments of an Anabaena culture under controlled conditions.
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16
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Philippi M, Kitzinger K, Berg JS, Tschitschko B, Kidane AT, Littmann S, Marchant HK, Storelli N, Winkel LHE, Schubert CJ, Mohr W, Kuypers MMM. Purple sulfur bacteria fix N 2 via molybdenum-nitrogenase in a low molybdenum Proterozoic ocean analogue. Nat Commun 2021; 12:4774. [PMID: 34362886 PMCID: PMC8346585 DOI: 10.1038/s41467-021-25000-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Accepted: 07/15/2021] [Indexed: 01/04/2023] Open
Abstract
Biological N2 fixation was key to the expansion of life on early Earth. The N2-fixing microorganisms and the nitrogenase type used in the Proterozoic are unknown, although it has been proposed that the canonical molybdenum-nitrogenase was not used due to low molybdenum availability. We investigate N2 fixation in Lake Cadagno, an analogue system to the sulfidic Proterozoic continental margins, using a combination of biogeochemical, molecular and single cell techniques. In Lake Cadagno, purple sulfur bacteria (PSB) are responsible for high N2 fixation rates, to our knowledge providing the first direct evidence for PSB in situ N2 fixation. Surprisingly, no alternative nitrogenases are detectable, and N2 fixation is exclusively catalyzed by molybdenum-nitrogenase. Our results show that molybdenum-nitrogenase is functional at low molybdenum conditions in situ and that in contrast to previous beliefs, PSB may have driven N2 fixation in the Proterozoic ocean.
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Affiliation(s)
- Miriam Philippi
- Department of Biogeochemistry, Max Planck Institute for Marine Microbiology, Bremen, Germany
| | - Katharina Kitzinger
- Department of Biogeochemistry, Max Planck Institute for Marine Microbiology, Bremen, Germany.
| | - Jasmine S Berg
- Department of Environmental Systems Science, ETH-Zurich, Zurich, Switzerland
| | - Bernhard Tschitschko
- Department of Biogeochemistry, Max Planck Institute for Marine Microbiology, Bremen, Germany
| | - Abiel T Kidane
- Department of Biogeochemistry, Max Planck Institute for Marine Microbiology, Bremen, Germany
| | - Sten Littmann
- Department of Biogeochemistry, Max Planck Institute for Marine Microbiology, Bremen, Germany
| | - Hannah K Marchant
- Department of Biogeochemistry, Max Planck Institute for Marine Microbiology, Bremen, Germany
| | - Nicola Storelli
- Laboratory of Applied Microbiology, Department of Environment, Constructions and Design, University of Applied Sciences of Southern Switzerland (SUPSI), Bellinzona, Switzerland
| | - Lenny H E Winkel
- Department of Environmental Systems Science, ETH-Zurich, Zurich, Switzerland.,Eawag, Swiss Federal Institute of Aquatic Science and Technology, Dübendorf, Switzerland
| | - Carsten J Schubert
- Department of Environmental Systems Science, ETH-Zurich, Zurich, Switzerland.,Eawag, Swiss Federal Institute of Aquatic Science and Technology, Kastanienbaum, Switzerland
| | - Wiebke Mohr
- Department of Biogeochemistry, Max Planck Institute for Marine Microbiology, Bremen, Germany
| | - Marcel M M Kuypers
- Department of Biogeochemistry, Max Planck Institute for Marine Microbiology, Bremen, Germany
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17
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Klawonn I, Van den Wyngaert S, Parada AE, Arandia-Gorostidi N, Whitehouse MJ, Grossart HP, Dekas AE. Characterizing the "fungal shunt": Parasitic fungi on diatoms affect carbon flow and bacterial communities in aquatic microbial food webs. Proc Natl Acad Sci U S A 2021; 118:e2102225118. [PMID: 34074785 PMCID: PMC8201943 DOI: 10.1073/pnas.2102225118] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Microbial interactions in aquatic environments profoundly affect global biogeochemical cycles, but the role of microparasites has been largely overlooked. Using a model pathosystem, we studied hitherto cryptic interactions between microparasitic fungi (chytrid Rhizophydiales), their diatom host Asterionella, and cell-associated and free-living bacteria. We analyzed the effect of fungal infections on microbial abundances, bacterial taxonomy, cell-to-cell carbon transfer, and cell-specific nitrate-based growth using microscopy (e.g., fluorescence in situ hybridization), 16S rRNA gene amplicon sequencing, and secondary ion mass spectrometry. Bacterial abundances were 2 to 4 times higher on individual fungal-infected diatoms compared to healthy diatoms, particularly involving Burkholderiales. Furthermore, taxonomic compositions of both diatom-associated and free-living bacteria were significantly different between noninfected and fungal-infected cocultures. The fungal microparasite, including diatom-associated sporangia and free-swimming zoospores, derived ∼100% of their carbon content from the diatom. By comparison, transfer efficiencies of photosynthetic carbon were lower to diatom-associated bacteria (67 to 98%), with a high cell-to-cell variability, and even lower to free-living bacteria (32%). Likewise, nitrate-based growth for the diatom and fungi was synchronized and faster than for diatom-associated and free-living bacteria. In a natural lacustrine system, where infection prevalence reached 54%, we calculated that 20% of the total diatom-derived photosynthetic carbon was shunted to the parasitic fungi, which can be grazed by zooplankton, thereby accelerating carbon transfer to higher trophic levels and bypassing the microbial loop. The herein termed "fungal shunt" can thus significantly modify the fate of photosynthetic carbon and the nature of phytoplankton-bacteria interactions, with implications for diverse pelagic food webs and global biogeochemical cycles.
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Affiliation(s)
- Isabell Klawonn
- Department of Earth System Science, Stanford University, Stanford, CA 94305;
| | - Silke Van den Wyngaert
- Department of Experimental Limnology, Leibniz-Institute of Freshwater Ecology and Inland Fisheries, 12587 Berlin, Germany
| | - Alma E Parada
- Department of Earth System Science, Stanford University, Stanford, CA 94305
| | | | - Martin J Whitehouse
- Department of Geosciences, Swedish Museum of Natural History, 104 05 Stockholm, Sweden
| | - Hans-Peter Grossart
- Department of Experimental Limnology, Leibniz-Institute of Freshwater Ecology and Inland Fisheries, 12587 Berlin, Germany
- Institute of Biochemistry and Biology, Potsdam University, 14476 Potsdam, Germany
| | - Anne E Dekas
- Department of Earth System Science, Stanford University, Stanford, CA 94305;
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18
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Pascault N, Rué O, Loux V, Pédron J, Martin V, Tambosco J, Bernard C, Humbert JF, Leloup J. Insights into the cyanosphere: capturing the respective metabolisms of cyanobacteria and chemotrophic bacteria in natural conditions? ENVIRONMENTAL MICROBIOLOGY REPORTS 2021; 13:364-374. [PMID: 33763994 DOI: 10.1111/1758-2229.12944] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Accepted: 03/07/2021] [Indexed: 06/12/2023]
Abstract
Specific interactions have been highlighted between cyanobacteria and chemotrophic bacteria within the cyanosphere, suggesting that nutrients recycling could be optimized by cyanobacteria/bacteria exchanges. In order to determine the respective metabolic roles of the cyanobacterial and bacterial consortia (microbiome), a day-night metatranscriptomic analysis was performed on Dolichospermum sp. (N2 -fixer) and Microcystis sp. (non N2 -fixer) natural blooms occurring successively within a French peri-urban lake. The taxonomical and functional analysis of the metatranscriptoms have highlighted specific association of bacteria within the cyanosphere, driven by the cyanobacteria identity, without strongly modifying the functional composition of the microbiomes, suggesting functional redundancy within the cyanosphere. Moreover, the functional composition of these active communities was driven by the living mode. During the two successive bloom events, it appeared that NH4 + (newly fixed and/or allochthonous) was preferentially transformed into amino acids for the both the microbiome and the cyanobacteria, while phosphate metabolism was enhanced, suggesting that due to a high cellular growth, P limitation might take place within the cyanosphere consortium.
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Affiliation(s)
- Noémie Pascault
- UMR 7618 iEES-Paris Sorbonne Université 4 place Jussieu - 75252 Paris Cedex 05, France
| | - Olivier Rué
- Université Paris-Saclay, INRAE, BioinfOmics, MIGALE Bioinformatics Facility, Jouy-en-Josas, 78350, France
| | - Valentin Loux
- Université Paris-Saclay, INRAE, BioinfOmics, MIGALE Bioinformatics Facility, Jouy-en-Josas, 78350, France
| | - Jacques Pédron
- UMR 7618 iEES-Paris Sorbonne Université 4 place Jussieu - 75252 Paris Cedex 05, France
| | - Véronique Martin
- Université Paris-Saclay, INRAE, BioinfOmics, MIGALE Bioinformatics Facility, Jouy-en-Josas, 78350, France
| | - Jennifer Tambosco
- UMR 7618 iEES-Paris Sorbonne Université 4 place Jussieu - 75252 Paris Cedex 05, France
| | - Cécile Bernard
- UMR 7245 MCAM Muséum National d'Histoire Naturelle - CNRS, 75231 Paris Cedex 05, France
| | - Jean-François Humbert
- UMR 7618 iEES-Paris Sorbonne Université 4 place Jussieu - 75252 Paris Cedex 05, France
| | - Julie Leloup
- UMR 7618 iEES-Paris Sorbonne Université 4 place Jussieu - 75252 Paris Cedex 05, France
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19
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Imran A, Hakim S, Tariq M, Nawaz MS, Laraib I, Gulzar U, Hanif MK, Siddique MJ, Hayat M, Fraz A, Ahmad M. Diazotrophs for Lowering Nitrogen Pollution Crises: Looking Deep Into the Roots. Front Microbiol 2021; 12:637815. [PMID: 34108945 PMCID: PMC8180554 DOI: 10.3389/fmicb.2021.637815] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Accepted: 03/24/2021] [Indexed: 12/14/2022] Open
Abstract
During and after the green revolution in the last century, agrochemicals especially nitrogen (N) were extensively used. However, it resulted in a remarkable increase in crop yield but drastically reduced soil fertility; increased the production cost, food prices, and carbon footprints; and depleted the fossil reserves with huge penalties to the environment and ecological sustainability. The groundwater, rivers, and oceans are loaded with N excess which is an environmental catastrophe. Nitrogen emissions (e.g., ammonia, nitrogen oxide, nitrous oxide) play an important role in global climate change and contribute to particulate matter and acid rain causing respiratory problems, cancers, and damage to forests and buildings. Therefore, the nitrogen-polluted planet Earth needs concerted global efforts to avoid the disaster. Improved agricultural N management focuses on the synchronization of crop N demand and N supply along with improving the N-use efficiency of the crops. However, there is very little focus on the natural sources of N available for plants in the form of diazotrophic bacteria present inside or on the root surface and the rhizosphere. These diazotrophs are the mini-nitrogen factories that convert available (78%) atmospheric N2 to ammonia through a process known as "biological nitrogen fixation" which is then taken up by the plants for its metabolic functioning. Diazotrophs also stimulate root architecture by producing plant hormones and hence improve the plant's overall ability to uptake nutrients and water. In recent years, nanotechnology has revolutionized the whole agri-industry by introducing nano-fertilizers and coated/slow-releasing fertilizers. With this in mind, we tried to explore the following questions: To what extent can the crop N requirements be met by diazotroph inoculation? Can N input to agriculture be managed in a way leading to environmental benefits and farmers saving money? Can nanotechnology help in technological advancement of diazotroph application? The review suggests that an integrated technology based on slow-releasing nano-fertilizer combined with diazotrophs should be adopted to decrease nitrogen inputs to the agricultural system. This integrated technology would minimize N pollution and N losses to much extent.
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Affiliation(s)
- Asma Imran
- Division of Soil and Environmental Biotechnology, National Institute for Biotechnology and Genetic Engineering-Campus-Pakistan Institute of Engineering and Applied Sciences (NIBGE-C-PIEAS), Faisalabad, Pakistan
| | - Sughra Hakim
- Division of Soil and Environmental Biotechnology, National Institute for Biotechnology and Genetic Engineering-Campus-Pakistan Institute of Engineering and Applied Sciences (NIBGE-C-PIEAS), Faisalabad, Pakistan
| | - Mohsin Tariq
- Division of Soil and Environmental Biotechnology, National Institute for Biotechnology and Genetic Engineering-Campus-Pakistan Institute of Engineering and Applied Sciences (NIBGE-C-PIEAS), Faisalabad, Pakistan
- Department of Bioinformatics and Biotechnology, Government College University, Faisalabad, Pakistan
- Department of Botany, Government College University, Faisalabad, Pakistan
| | - Muhammad Shoib Nawaz
- Division of Soil and Environmental Biotechnology, National Institute for Biotechnology and Genetic Engineering-Campus-Pakistan Institute of Engineering and Applied Sciences (NIBGE-C-PIEAS), Faisalabad, Pakistan
| | - Iqra Laraib
- Division of Soil and Environmental Biotechnology, National Institute for Biotechnology and Genetic Engineering-Campus-Pakistan Institute of Engineering and Applied Sciences (NIBGE-C-PIEAS), Faisalabad, Pakistan
| | - Umaira Gulzar
- Division of Soil and Environmental Biotechnology, National Institute for Biotechnology and Genetic Engineering-Campus-Pakistan Institute of Engineering and Applied Sciences (NIBGE-C-PIEAS), Faisalabad, Pakistan
- Department of Botany, University of Bagh, Kotli, Pakistan
| | - Muhammad Kashif Hanif
- Division of Soil and Environmental Biotechnology, National Institute for Biotechnology and Genetic Engineering-Campus-Pakistan Institute of Engineering and Applied Sciences (NIBGE-C-PIEAS), Faisalabad, Pakistan
- Department of Biotechnology, Institute of Molecular Biology and Biotechnology, University of Lahore, Sargodha, Pakistan
| | - Muhammad Jawad Siddique
- Division of Soil and Environmental Biotechnology, National Institute for Biotechnology and Genetic Engineering-Campus-Pakistan Institute of Engineering and Applied Sciences (NIBGE-C-PIEAS), Faisalabad, Pakistan
| | - Mahnoor Hayat
- Division of Soil and Environmental Biotechnology, National Institute for Biotechnology and Genetic Engineering-Campus-Pakistan Institute of Engineering and Applied Sciences (NIBGE-C-PIEAS), Faisalabad, Pakistan
| | - Ahmad Fraz
- Division of Soil and Environmental Biotechnology, National Institute for Biotechnology and Genetic Engineering-Campus-Pakistan Institute of Engineering and Applied Sciences (NIBGE-C-PIEAS), Faisalabad, Pakistan
- Department of Bioinformatics and Biotechnology, Government College University, Faisalabad, Pakistan
- Department of Botany, Government College University, Faisalabad, Pakistan
| | - Muhammad Ahmad
- Division of Soil and Environmental Biotechnology, National Institute for Biotechnology and Genetic Engineering-Campus-Pakistan Institute of Engineering and Applied Sciences (NIBGE-C-PIEAS), Faisalabad, Pakistan
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20
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Nitrogen Sources and Iron Availability Affect Pigment Biosynthesis and Nutrient Consumption in Anabaena sp. UTEX 2576. Microorganisms 2021; 9:microorganisms9020431. [PMID: 33669780 PMCID: PMC7922959 DOI: 10.3390/microorganisms9020431] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Revised: 02/15/2021] [Accepted: 02/16/2021] [Indexed: 11/17/2022] Open
Abstract
Anabaena sp. UTEX 2576 metabolizes multiple nitrogen (N) sources and is deemed a biotechnological platform for chemical production. Cyanobacteria have been identified as prolific producers of biofertilizers, biopolymers, biofuels, and other bioactive compounds. Here, we analyze the effect of different N-sources and Fe availability on the bioproduction of phycobiliproteins and β-carotene. We characterize nutrient demand in modified BG11 media, including data on CO2 fixation rates, N-source consumption, and mineral utilization (e.g., phosphorus (P), and 11 metallic elements). Results suggest that non-diazotrophic cultures grow up to 60% faster than diazotrophic cells, resulting in 20% higher CO2-fixation rates. While the production of β-carotene was maximum in medium with NaNO3, Fe starvation increased the cellular abundance of C-phycocyanin and allophycocyanin by at least 22%. Compared to cells metabolizing NaNO3 and N2, cultures adapted to urea media increased their P, calcium and manganese demands by at least 72%, 97% and 76%, respectively. Variations on pigmentation and nutrient uptake were attributed to changes in phycocyanobilin biosynthesis, light-induced oxidation of carotenoids, and urea-promoted peroxidation. This work presents insights into developing optimal Anabaena culture for efficient operations of bioproduction and wastewater bioremediation with cyanobacteria.
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21
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Han Y, Aziz TN, Del Giudice D, Hall NS, Obenour DR. Exploring nutrient and light limitation of algal production in a shallow turbid reservoir. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 269:116210. [PMID: 33316498 DOI: 10.1016/j.envpol.2020.116210] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 11/26/2020] [Accepted: 11/30/2020] [Indexed: 06/12/2023]
Abstract
Harmful algal blooms are increasingly recognized as a threat to the integrity of freshwater reservoirs, which serve as water supplies, wildlife habitats, and recreational attractions. While algal growth and accumulation is controlled by many environmental factors, the relative importance of these factors is unclear, particularly for turbid eutrophic systems. Here we develop and compare two models that test the relative importance of vertical mixing, light, and nutrients for explaining chlorophyll-a variability in shallow (2-3 m) embayments of a eutrophic reservoir, Jordan Lake, North Carolina. One is a multiple linear regression (statistical) model and the other is a process-based (mechanistic) model. Both models are calibrated using a 15-year data record of chlorophyll-a concentration (2003-2018) for the seasonal period of cyanobacteria dominance (June-October). The mechanistic model includes a novel representation of vertical mixing and is calibrated in a Bayesian framework, which allows for data-driven inference of important process rates. Both models show that chlorophyll-a concentration is much more responsive to nutrient variability than mixing, light, or temperature. While both models explain approximately 60% of the variability in chlorophyll-a, the mechanistic model is more robust in cross-validation and provides a more comprehensive assessment of algal drivers. Overall, these models indicate that nutrient reductions, rather than changes in mixing or background turbidity, are critical to controlling cyanobacteria in a shallow eutrophic freshwater system.
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Affiliation(s)
- Yue Han
- Department of Civil, Construction, and Environmental Engineering, North Carolina State University, Raleigh, NC, USA.
| | - Tarek N Aziz
- Department of Civil, Construction, and Environmental Engineering, North Carolina State University, Raleigh, NC, USA
| | - Dario Del Giudice
- Department of Civil, Construction, and Environmental Engineering, North Carolina State University, Raleigh, NC, USA
| | - Nathan S Hall
- Institute of Marine Sciences, University of North Carolina at Chapel Hill, Morehead City, NC, USA
| | - Daniel R Obenour
- Department of Civil, Construction, and Environmental Engineering, North Carolina State University, Raleigh, NC, USA
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22
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Olofsson M, Klawonn I, Karlson B. Nitrogen fixation estimates for the Baltic Sea indicate high rates for the previously overlooked Bothnian Sea. AMBIO 2021; 50:203-214. [PMID: 32314265 PMCID: PMC7708615 DOI: 10.1007/s13280-020-01331-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Revised: 11/22/2019] [Accepted: 03/20/2020] [Indexed: 05/05/2023]
Abstract
Dense blooms of diazotrophic filamentous cyanobacteria are formed every summer in the Baltic Sea. We estimated their contribution to nitrogen fixation by combining two decades of cyanobacterial biovolume monitoring data with recently measured genera-specific nitrogen fixation rates. In the Bothnian Sea, estimated nitrogen fixation rates were 80 kt N year-1, which has doubled during recent decades and now exceeds external loading from rivers and atmospheric deposition of 69 kt year-1. The estimated contribution to the Baltic Proper was 399 kt N year-1, which agrees well with previous estimates using other approaches and is greater than the external input of 374 kt N year-1. Our approach can potentially be applied to continuously estimate nitrogen loads via nitrogen fixation. Those estimates are crucial for ecosystem adaptive management since internal nitrogen loading may counteract the positive effects of decreased external nutrient loading.
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Affiliation(s)
- Malin Olofsson
- Research and Development, Oceanography, Swedish Meteorological and Hydrological Institute, Sven Källfelts Gata 15, 426 71 Västra Frölunda, Gothenburg, Sweden
- Present Address: Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Isabell Klawonn
- Department of Experimental Limnology, IGB-Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Alte Fischerhütte 2, OT Neuglobsow, Stechlin, 16775 Berlin, Germany
| | - Bengt Karlson
- Research and Development, Oceanography, Swedish Meteorological and Hydrological Institute, Sven Källfelts Gata 15, 426 71 Västra Frölunda, Gothenburg, Sweden
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23
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Zilius M, Samuiloviene A, Stanislauskienė R, Broman E, Bonaglia S, Meškys R, Zaiko A. Depicting Temporal, Functional, and Phylogenetic Patterns in Estuarine Diazotrophic Communities from Environmental DNA and RNA. MICROBIAL ECOLOGY 2021; 81:36-51. [PMID: 32803362 DOI: 10.1007/s00248-020-01562-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Accepted: 07/20/2020] [Indexed: 06/11/2023]
Abstract
Seasonally nitrogen-limited and phosphorus-replete temperate coastal waters generally host dense and diverse diazotrophic communities. Despite numerous studies in marine systems, little is known about diazotrophs and their functioning in oligohaline estuarine environments. Here we applied a combination of nifH transcript and metagenomic shotgun sequencing approaches to investigate temporal shifts in taxonomic composition and nifH activity of size-fractionated diazotrophic communities in a shallow and mostly freshwater coastal lagoon. Patterns in active nifH phylotypes exhibited a clear seasonal succession, which reflected their different tolerances to temperature change and nitrogen (N) availability. Thus, in spring, heterotrophic diazotrophs (Proteobacteria) dominated the nifH phylotypes, while increasing water temperature and depletion of inorganic N fostered heterocystous Cyanobacteria in summer. Metagenomic data demonstrated four main N-cycling pathways and three of them with a clear seasonal pattern: denitrification (spring) → N2 fixation (summer) → assimilative NO3- reduction (fall), with NH4+ uptake into cells occurring across all seasons. Although a substantial denitrification signal was observed in spring, it could have originated from the re-suspended benthic rather than planktonic community. Our results contribute to a better understanding of the realized genetic potential of pelagic N2 fixation and its seasonal dynamics in oligohaline estuarine ecosystems, which are natural coastal biogeochemical reactors.
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Affiliation(s)
- Mindaugas Zilius
- Marine Research Institute, Klaipeda University, 92294, Klaipeda, Lithuania.
| | | | - Rūta Stanislauskienė
- Department of Molecular Microbiology and Biotechnology, Institute of Biochemistry, Life Sciences Center, Vilnius University, 10257 Vilnius, Lithuania
| | - Elias Broman
- Baltic Sea Center, Stockholm University, Stockholm, Sweden
- Department of Ecology, Environment and Plant Sciences, Stockholm University, 10691 Stockholm, Sweden
| | - Stefano Bonaglia
- Marine Research Institute, Klaipeda University, 92294, Klaipeda, Lithuania
- Department of Ecology, Environment and Plant Sciences, Stockholm University, 10691 Stockholm, Sweden
- Department of Biology, University of Southern Denmark, 5230, Odense, Denmark
- Department of Marine Sciences, University of Gothenburg, Box 461, 40530 Gothenburg, Sweden
| | - Rolandas Meškys
- Department of Molecular Microbiology and Biotechnology, Institute of Biochemistry, Life Sciences Center, Vilnius University, 10257 Vilnius, Lithuania
| | - Anastasija Zaiko
- Coastal and Freshwater Group, Cawthron Institute, 7042 Nelson, New Zealand
- Institute of Marine Science, University of Auckland, Private Bag 92019, Auckland, New Zealand
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24
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Zulkefli NS, Hwang SJ. Heterocyst Development and Diazotrophic Growth of Anabaena variabilis under Different Nitrogen Availability. Life (Basel) 2020; 10:E279. [PMID: 33202779 PMCID: PMC7696877 DOI: 10.3390/life10110279] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 11/09/2020] [Accepted: 11/11/2020] [Indexed: 11/17/2022] Open
Abstract
Nitrogen is globally limiting primary production in the ocean, but some species of cyanobacteria can carry out nitrogen (N) fixation using specialized cells known as heterocysts. However, the effect of N sources and their availability on heterocyst development is not yet fully understood. This study aimed to evaluate the effect of various inorganic N sources on the heterocyst development and cellular growth in an N-fixing cyanobacterium, Anabaena variabilis. Growth rate, heterocyst development, and cellular N content of the cyanobacteria were examined under varying nitrate and ammonium concentrations. A. variabilis exhibited high growth rate both in the presence and absence of N sources regardless of their concentration. Ammonium was the primary source of N in A. variabilis. Even the highest concentrations of both nitrate (1.5 g L-1 as NaNO3) and ammonium (0.006 g L-1 as Fe-NH4-citrate) did not exhibit an inhibitory effect on heterocyst development. Heterocyst production positively correlated with the cell N quota and negatively correlated with vegetative cell growth, indicating that both of the processes were interdependent. Taken together, N deprivation triggers heterocyst production for N fixation. This study outlines the difference in heterocyst development and growth in A. variabilis under different N sources.
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Affiliation(s)
| | - Soon-Jin Hwang
- Department of Environmental Health Science and Human and Eco-care Center, Konkuk University, Seoul 05029, Korea
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25
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Olofsson M, Hagan JG, Karlson B, Gamfeldt L. Large seasonal and spatial variation in nano- and microphytoplankton diversity along a Baltic Sea-North Sea salinity gradient. Sci Rep 2020; 10:17666. [PMID: 33077730 PMCID: PMC7572517 DOI: 10.1038/s41598-020-74428-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Accepted: 09/30/2020] [Indexed: 11/09/2022] Open
Abstract
Aquatic phytoplankton experience large fluctuations in environmental conditions during seasonal succession and across salinity gradients, but the impact of this variation on their diversity is poorly understood. We examined spatio-temporal variation in nano- and microphytoplankton (> 2 µm) community structure using almost two decades of light-microscope based monitoring data. The dataset encompasses 19 stations that span a salinity gradient from 2.8 to 35 along the Swedish coastline. Spatially, both regional and local phytoplankton diversity increased with broad-scale salinity variation. Diatoms dominated at high salinity and the proportion of cyanobacteria increased with decreasing salinity. Temporally, cell abundance peaked in winter-spring at high salinity but in summer at low salinity. This was likely due to large filamentous cyanobacteria blooms that occur in summer in low salinity areas, but which are absent in higher salinities. In contrast, phytoplankton local diversity peaked in spring at low salinity but in fall and winter at high salinity. Whilst differences in seasonal variation in cell abundance were reasonably well-explained by variation in salinity and nutrient availability, variation in local-scale phytoplankton diversity was poorly predicted by environmental variables. Overall, we provide insights into the causes of spatio-temporal variation in coastal phytoplankton community structure while also identifying knowledge gaps.
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Affiliation(s)
- Malin Olofsson
- Research and Development, Oceanography, Swedish Meteorological and Hydrological Institute, Sven Källfelts gata 15, 426 71, Västra Frölunda, Sweden.
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Box 7050, 750 07, Uppsala, Sweden.
| | - James G Hagan
- Department of Marine Sciences, University of Gothenburg, Box 100, 405 30 Gothenburg, Sweden
- Gothenburg Global Biodiversity Centre, Box 461, 405 30, Gothenburg, Sweden
| | - Bengt Karlson
- Research and Development, Oceanography, Swedish Meteorological and Hydrological Institute, Sven Källfelts gata 15, 426 71, Västra Frölunda, Sweden
| | - Lars Gamfeldt
- Department of Marine Sciences, University of Gothenburg, Box 100, 405 30 Gothenburg, Sweden
- Gothenburg Global Biodiversity Centre, Box 461, 405 30, Gothenburg, Sweden
- Centre for Sea and Society, Box 260, 405 30, Gothenburg, Sweden
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26
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Morimoto D, Šulčius S, Yoshida T. Viruses of freshwater bloom-forming cyanobacteria: genomic features, infection strategies and coexistence with the host. ENVIRONMENTAL MICROBIOLOGY REPORTS 2020; 12:486-502. [PMID: 32754956 DOI: 10.1111/1758-2229.12872] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Revised: 07/28/2020] [Accepted: 07/31/2020] [Indexed: 06/11/2023]
Abstract
Freshwater bloom-forming cyanobacteria densely grow in the aquatic environments, leading to an increase in the viral-contact rate. They possess numerous antiviral genes, as well as cell differentiation- and physiological performance-related genes, owing to genome expansion. Their genomic features and unique lifestyles suggest that they coexist with cyanoviruses in ways different from marine cyanobacteria. Furthermore, genome contents of isolated freshwater bloom-forming cyanobacterial viruses have little in common with those of marine cyanoviruses studied to date. They lack the marine cyanoviral hallmark genes that sustain photosynthetic activity and redirect host metabolism to viral reproduction; therefore, they are predicted to share metabolisms and precursor pools with host cyanobacteria to ensure efficient viral reproduction and avoid nutrient deficiencies and antiviral response. Additionally, cyanovirus-cyanobacteria coexistence strategies may change as bloom density increases. Diverse genotypic populations of cyanoviruses and hosts coexist and fluctuate under high viral-contact rate conditions, leading to their rapid coevolution through antiviral responses. The ancestral and newly evolved genotypes coexist, thereby expanding the diversity levels of host and viral populations. Bottleneck events occurring due to season-related decreases in bloom-forming species abundance provide each genotype within cyanobacterial population an equal chance to increase in prevalence during the next bloom and enhance further diversification.
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Affiliation(s)
- Daichi Morimoto
- Graduate School of Agriculture, Kyoto University, Kitashirakawa-Oiwake, Sakyo-ku, Kyoto, 606-8502, Japan
| | - Sigitas Šulčius
- Laboratory of Algology and Microbial Ecology, Nature Research Centre, Akademijos 2, Vilnius, 08412, Lithuania
| | - Takashi Yoshida
- Graduate School of Agriculture, Kyoto University, Kitashirakawa-Oiwake, Sakyo-ku, Kyoto, 606-8502, Japan
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27
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Kuznecova J, Šulčius S, Vogts A, Voss M, Jürgens K, Šimoliūnas E. Nitrogen Flow in Diazotrophic Cyanobacterium Aphanizomenon flos-aquae Is Altered by Cyanophage Infection. Front Microbiol 2020; 11:2010. [PMID: 32973727 PMCID: PMC7466765 DOI: 10.3389/fmicb.2020.02010] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Accepted: 07/29/2020] [Indexed: 12/03/2022] Open
Abstract
Viruses can significantly influence cyanobacteria population dynamics and activity, and through this the biogeochemical cycling of major nutrients. However, surprisingly little attention has been given to understand how viral infections alter the ability of diazotrophic cyanobacteria for atmospheric nitrogen fixation and its release to the environment. This study addressed the importance of cyanophages for net 15N2 assimilation rate, expression of nitrogenase reductase gene (nifH) and changes in nitrogen enrichment (15N/14N) in the diazotrophic cyanobacterium Aphanizomenon flos-aquae during infection by the cyanophage vB_AphaS-CL131. We found that while the growth of A. flos-aquae was inhibited by cyanophage addition (decreased from 0.02 h–1 to 0.002 h–1), there were no significant differences in nitrogen fixation rates (control: 22.7 × 10–7 nmol N heterocyte–1; infected: 23.9 × 10–7 nmol N heterocyte–1) and nifH expression level (control: 0.6–1.6 transcripts heterocyte–1; infected: 0.7–1.1 transcripts heterocyte–1) between the infected and control A. flos-aquae cultures. This implies that cyanophage genome replication and progeny production within the vegetative cells does not interfere with the N2 fixation reactions in the heterocytes of these cyanobacteria. However, higher 15N enrichment at the poles of heterocytes of the infected A. flos-aquae, revealed by NanoSIMS analysis indicates the accumulation of fixed nitrogen in response to cyanophage addition. This suggests reduced nitrogen transport to vegetative cells and the alterations in the flow of fixed nitrogen within the filaments. In addition, we found that cyanophage lysis resulted in a substantial release of ammonium into culture medium. Cyanophage infection seems to substantially redirect N flow from cyanobacterial biomass to the production of N storage compounds and N release.
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Affiliation(s)
- Jolita Kuznecova
- Laboratory of Algology and Microbial Ecology, Nature Research Centre, Vilnius, Lithuania
| | - Sigitas Šulčius
- Laboratory of Algology and Microbial Ecology, Nature Research Centre, Vilnius, Lithuania
| | - Angela Vogts
- Section Biological Oceanography, Leibniz Institute for Baltic Sea Research, Warnemünde, Germany
| | - Maren Voss
- Section Biological Oceanography, Leibniz Institute for Baltic Sea Research, Warnemünde, Germany
| | - Klaus Jürgens
- Section Biological Oceanography, Leibniz Institute for Baltic Sea Research, Warnemünde, Germany
| | - Eugenijus Šimoliūnas
- Department of Molecular Microbiology and Biotechnology, Life Sciences Center, Vilnius University, Vilnius, Lithuania
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28
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Stenow R, Olofsson M, Robertson EK, Kourtchenko O, Whitehouse MJ, Ploug H, Godhe A. Resting Stages of Skeletonema marinoi Assimilate Nitrogen From the Ambient Environment Under Dark, Anoxic Conditions. JOURNAL OF PHYCOLOGY 2020; 56:699-708. [PMID: 32012281 DOI: 10.1111/jpy.12975] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Accepted: 01/02/2020] [Indexed: 06/10/2023]
Abstract
The planktonic marine diatom Skeletonema marinoi forms resting stages, which can survive for decades buried in aphotic, anoxic sediments and resume growth when re-exposed to light, oxygen, and nutrients. The mechanisms by which they maintain cell viability during dormancy are poorly known. Here, we investigated cell-specific nitrogen (N) and carbon (C) assimilation and survival rate in resting stages of three S. marinoi strains. Resting stages were incubated with stable isotopes of dissolved inorganic N (DIN), in the form of 15 N-ammonium (NH4+ ) or -nitrate (NO3- ) and dissolved inorganic C (DIC) as 13 C-bicarbonate (HCO3- ) under dark and anoxic conditions for 2 months. Particulate C and N concentration remained close to the Redfield ratio (6.6) during the experiment, indicating viable diatoms. However, survival varied between <0.1% and 47.6% among the three different S. marinoi strains, and overall survival was higher when NO3- was available. One strain did not survive in the NH4+ treatment. Using secondary ion mass spectrometry (SIMS), we quantified assimilation of labeled DIC and DIN from the ambient environment within the resting stages. Dark fixation of DIC was insignificant across all strains. Significant assimilation of 15 N-NO3- and 15 N-NH4+ occurred in all S. marinoi strains at rates that would double the nitrogenous biomass over 77-380 years depending on strain and treatment. Hence, resting stages of S. marinoi assimilate N from the ambient environment at slow rates during darkness and anoxia. This activity may explain their well-documented long survival and swift resumption of vegetative growth after dormancy in dark and anoxic sediments.
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Affiliation(s)
- Rickard Stenow
- Department of Marine Sciences, University of Gothenburg, Box 461, SE 405 30, Gothenburg, Sweden
| | - Malin Olofsson
- Department of Marine Sciences, University of Gothenburg, Box 461, SE 405 30, Gothenburg, Sweden
| | - Elizabeth K Robertson
- Department of Marine Sciences, University of Gothenburg, Box 461, SE 405 30, Gothenburg, Sweden
| | - Olga Kourtchenko
- Department of Marine Sciences, University of Gothenburg, Box 461, SE 405 30, Gothenburg, Sweden
| | | | - Helle Ploug
- Department of Marine Sciences, University of Gothenburg, Box 461, SE 405 30, Gothenburg, Sweden
| | - Anna Godhe
- Department of Marine Sciences, University of Gothenburg, Box 461, SE 405 30, Gothenburg, Sweden
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29
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Olofsson M, Suikkanen S, Kobos J, Wasmund N, Karlson B. Basin-specific changes in filamentous cyanobacteria community composition across four decades in the Baltic Sea. HARMFUL ALGAE 2020; 91:101685. [PMID: 32057344 DOI: 10.1016/j.hal.2019.101685] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Revised: 09/23/2019] [Accepted: 09/29/2019] [Indexed: 06/10/2023]
Abstract
Almost every summer, dense blooms of filamentous cyanobacteria are formed in the Baltic Sea. These blooms may cause problems for tourism and ecosystem services, where surface accumulations and beach fouling are commonly occurring. Future changes in environmental drivers, including climate change and other anthropogenic disturbances, may further enhance these problems. By compiling monitoring data from countries adjacent to the Baltic Sea, we present spatial and temporal genus-specific distribution of diazotrophic filamentous cyanobacteria (Nostocales) during four decades (1979-2017). While the summer surface salinity decreased with a half up to one unit, the surface temperature in July-August increased with 2-3 °C in most sub-basins of the Baltic Sea, during the time period. The biovolumes of the toxic Nodularia spumigena did not change in any of the sub-basins during the period. On the other hand, the biovolume of the non-toxic Aphanizomenon sp. and the potentially toxic Dolichospermum spp. increased in the northern parts of the Baltic Sea, along with the decreased salinity and elevated temperatures, but Aphanizomenon sp. decreased in the southern parts despite decreased salinity and increased temperatures. These contradictory changes in biovolume of Aphanizomenon sp. between the northern and southern parts of the Baltic Sea may be due to basin-specific effects of the changed environmental conditions, or can be related to local adaptation by sub-populations of the genera. Overall, this comprehensive dataset presents insights to genus-specific bloom dynamics by potentially harmful diazotrophic filamentous cyanobacteria in the Baltic Sea.
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Affiliation(s)
- Malin Olofsson
- Research and Development, Oceanography, Swedish Meteorological and Hydrological Institute, Sven Källfelts Gata 15, 426 71, Västra Frölunda, Sweden.
| | - Sanna Suikkanen
- Marine Research Centre, Finnish Environment Institute, Latokartanonkaari 11, 00790, Helsinki, Finland.
| | - Justyna Kobos
- University of Gdansk, Faculty of Oceanography and Geography, Institute of Oceanography, Division of Marine Biotechnology, al. Marszałka Józefa Piłsudskiego 46, 81-378, Gdynia, Poland.
| | - Norbert Wasmund
- Leibniz Institute for Baltic Sea Research, Warnemünde, Seestrasse 15, D-18119, Rostock, Germany.
| | - Bengt Karlson
- Research and Development, Oceanography, Swedish Meteorological and Hydrological Institute, Sven Källfelts Gata 15, 426 71, Västra Frölunda, Sweden.
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Eigemann F, Vogts A, Voss M, Zoccarato L, Schulz-Vogt H. Distinctive tasks of different cyanobacteria and associated bacteria in carbon as well as nitrogen fixation and cycling in a late stage Baltic Sea bloom. PLoS One 2019; 14:e0223294. [PMID: 31830057 PMCID: PMC6907833 DOI: 10.1371/journal.pone.0223294] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Accepted: 11/19/2019] [Indexed: 01/18/2023] Open
Abstract
Cyanobacteria and associated heterotrophic bacteria hold key roles in carbon as well as nitrogen fixation and cycling in the Baltic Sea due to massive cyanobacterial blooms each summer. The species specific activities of different cyanobacterial species as well as the N- and C-exchange of associated heterotrophic bacteria in these processes, however, are widely unknown. Within one time series experiment we tested the cycling in a natural, late stage cyanobacterial bloom by adding 13C bi-carbonate and 15N2, and performed sampling after 10 min, 30 min, 1 h, 6 h and 24 h in order to determine the fixing species as well as the fate of the fixed carbon and nitrogen in the associations. Uptake of 15N and 13C isotopes by the most abundant cyanobacterial species as well as the most abundant associated heterotrophic bacterial groups was then analysed by NanoSIMS. Overall, the filamentous, heterocystous species Dolichospermum sp., Nodularia sp., and Aphanizomenon sp. revealed no or erratic uptake of carbon and nitrogen, indicating mostly inactive cells. In contrary, non-heterocystous Pseudanabaena sp. dominated the nitrogen and carbon fixation, with uptake rates up to 1.49 ± 0.47 nmol N h-1 l-1 and 2.55 ± 0.91 nmol C h-1 l-1. Associated heterotrophic bacteria dominated the subsequent nitrogen remineralization with uptake rates up to 1.2 ± 1.93 fmol N h-1 cell -1, but were also indicative for fixation of di-nitrogen.
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Affiliation(s)
- Falk Eigemann
- Department of Biological Oceanography, Leibniz Institute for Baltic Sea Research Warnemünde, Rostock, Germany
| | - Angela Vogts
- Department of Biological Oceanography, Leibniz Institute for Baltic Sea Research Warnemünde, Rostock, Germany
| | - Maren Voss
- Department of Biological Oceanography, Leibniz Institute for Baltic Sea Research Warnemünde, Rostock, Germany
| | - Luca Zoccarato
- Department of Stratified Lakes, Leibniz-Institute for Freshwater Ecology and Inland Fisheries, Stechlin, Germany
| | - Heide Schulz-Vogt
- Department of Biological Oceanography, Leibniz Institute for Baltic Sea Research Warnemünde, Rostock, Germany
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Gong B, Cao H, Peng C, Perčulija V, Tong G, Fang H, Wei X, Ouyang S. High-throughput sequencing and analysis of microbial communities in the mangrove swamps along the coast of Beibu Gulf in Guangxi, China. Sci Rep 2019; 9:9377. [PMID: 31253826 PMCID: PMC6599077 DOI: 10.1038/s41598-019-45804-w] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Accepted: 06/13/2019] [Indexed: 02/07/2023] Open
Abstract
Mangrove swamp is one of the world's richest and most productive marine ecosystems. This ecosystem also has a great ecological importance, but is highly susceptible to anthropogenic disturbances. The balance of mangrove ecosystem depends largely on the microbial communities in mangrove sediments. Thus, understanding how the mangrove microbial communities respond to spatial differences is essential for more accurate assessment of mangrove ecosystem health. To this end, we performed the first medium-distance (150 km) research on the biogeographic distribution of mangrove microbial communities. The hypervariable regions of 16S rRNA gene was sequenced by Illumina to compare the microbial communities in mangrove sediments collected from six locations (i.e. Zhenzhu harbor, Yuzhouping, Maowei Sea, Qinzhou harbor, Beihai city and Shankou) along the coastline of Beibu Gulf in Guangxi province, China. Collectively, Proteobacteria, Bacteroidetes, Chloroflexi, Actinobacteria, Parvarchaeota, Acidobacteria and Cyanobacteria were the predominant phyla in the mangrove sediments of this area. At genus level, the heat map of microbial communities reflected similarities between study sites and was in agreement with their biogeographic characteristics. Interestingly, the genera Desulfococcus, Arcobacter, Nitrosopumilus and Sulfurimonas showed differences in abundance between study sites. Furthermore, the principal component analysis (PCA) and unweighted UniFrac cluster tree of beta diversity were used to study the biogeographic diversity of the microbial communities. Relatively broader variation of microbial communities was found in Beihai city and Qinzhou harbour, suggesting that environmental condition and historical events may play an important role in shaping the bacterial communities as well. This is the first report on medium-distance range distribution of bacteria in the mangrove swamp ecosystem. Our data is valuable for monitoring and evaluation of the impact of human activity on mangrove habitats from the perspective of microbiome.
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Affiliation(s)
- Bin Gong
- Guangxi Key Laboratory of Marine Disaster in the Beibu Gulf, Beibu Gulf University, Qinzhou, 535000, China.,The Key Laboratory of Innate Immune Biology of Fujian Province, Provincial University Key Laboratory of Cellular Stress Response and Metabolic Regulation, Biomedical Research Center of South China, Key Laboratory of OptoElectronic Science and Technology for Medicine of Ministry of Education, College of Life Sciences, Fujian Normal University, Fuzhou, 350117, China
| | - Hongming Cao
- Guangxi Key Laboratory of Marine Disaster in the Beibu Gulf, Beibu Gulf University, Qinzhou, 535000, China
| | - Chunyan Peng
- Guangxi Key Laboratory of Marine Disaster in the Beibu Gulf, Beibu Gulf University, Qinzhou, 535000, China
| | - Vanja Perčulija
- The Key Laboratory of Innate Immune Biology of Fujian Province, Provincial University Key Laboratory of Cellular Stress Response and Metabolic Regulation, Biomedical Research Center of South China, Key Laboratory of OptoElectronic Science and Technology for Medicine of Ministry of Education, College of Life Sciences, Fujian Normal University, Fuzhou, 350117, China
| | - Guixiang Tong
- Guangxi Key Laboratory of Aquatic Genetic Breeding and Healthy Aquaculture, Academy of Fishery Sciences, Nanning, Guangxi, 530021, China
| | - Huaiyi Fang
- Guangxi Key Laboratory of Marine Disaster in the Beibu Gulf, Beibu Gulf University, Qinzhou, 535000, China
| | - Xinxian Wei
- Guangxi Key Laboratory of Aquatic Genetic Breeding and Healthy Aquaculture, Academy of Fishery Sciences, Nanning, Guangxi, 530021, China.
| | - Songying Ouyang
- The Key Laboratory of Innate Immune Biology of Fujian Province, Provincial University Key Laboratory of Cellular Stress Response and Metabolic Regulation, Biomedical Research Center of South China, Key Laboratory of OptoElectronic Science and Technology for Medicine of Ministry of Education, College of Life Sciences, Fujian Normal University, Fuzhou, 350117, China.
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Phosphate availability affects fixed nitrogen transfer from diazotrophs to their epibionts. ISME JOURNAL 2019; 13:2701-2713. [PMID: 31249392 PMCID: PMC6794295 DOI: 10.1038/s41396-019-0453-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Revised: 03/20/2019] [Accepted: 05/17/2019] [Indexed: 12/02/2022]
Abstract
Dinitrogen (N2) fixation is a major source of external nitrogen (N) to aquatic ecosystems and therefore exerts control over productivity. Studies have shown that N2 -fixers release freshly fixed N into the environment, but the causes for this N release are largely unclear. Here, we show that the availability of phosphate can directly affect the transfer of freshly fixed N to epibionts in filamentous, diazotrophic cyanobacteria. Stable-isotope incubations coupled to single-cell analyses showed that <1% and ~15% of freshly fixed N was transferred to epibionts of Aphanizomenon and Nodularia, respectively, at phosphate scarcity during a summer bloom in the Baltic Sea. When phosphate was added, the transfer of freshly fixed N to epibionts dropped to about half for Nodularia, whereas the release from Aphanizomenon increased slightly. At the same time, the growth rate of Nodularia roughly doubled, indicating that less freshly fixed N was released and was used for biomass production instead. Phosphate scarcity and the resulting release of freshly fixed N could explain the heavy colonization of Nodularia filaments by microorganisms during summer blooms. As such, the availability of phosphate may directly affect the partitioning of fixed N2 in colonies of diazotrophic cyanobacteria and may impact the interactions with their microbiome.
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Zhang J, Chen M, Huang J, Guo X, Zhang Y, Liu D, Wu R, He H, Wang J. Diversity of the microbial community and cultivable protease-producing bacteria in the sediments of the Bohai Sea, Yellow Sea and South China Sea. PLoS One 2019; 14:e0215328. [PMID: 30973915 PMCID: PMC6459509 DOI: 10.1371/journal.pone.0215328] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2019] [Accepted: 03/30/2019] [Indexed: 02/06/2023] Open
Abstract
The nitrogen (N) cycle is closely related to the stability of marine ecosystems. Microbial communities have been directly linked to marine N-cycling processes. However, systematic research on the bacterial community composition and diversity involved in N cycles in different seas is lacking. In this study, microbial diversity in the Bohai Sea (BHS), Yellow Sea (YS) and South China Sea (SCS) was surveyed by targeting the hypervariable V4 regions of the 16S rRNA gene using next-generation sequencing (NGS) technology. A total of 2,505,721 clean reads and 15,307 operational taxonomic units (OTUs) were obtained from 86 sediment samples from the three studied China seas. LEfSe analysis demonstrated that the SCS had more abundant microbial taxa than the BHS and YS. Diversity indices demonstrated that Proteobacteria and Planctomycetes were the dominant phyla in all three China seas. Canonical correspondence analysis (CCA) indicated that pH (P = 0.034) was the principal determining factors, while the organic matter content, depth and temperature had a minor correlated with the variations in sedimentary microbial community distribution. Cluster and functional analyses of microbial communities showed that chemoheterotrophic and aerobic chemoheterotrophic microorganisms widely exist in these three seas. Further research found that the cultivable protease-producing bacteria were mainly affiliated with the phyla Proteobacteria, Firmicutes and Bacteroidetes. It was very clear that Pseudoalteromonadaceae possessed the highest relative abundance in the three sea areas. The predominant protease-producing genera were Pseudoalteromonas and Bacillus. These results shed light on the differences in bacterial community composition, especially protease-producing bacteria, in these three China seas.
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Affiliation(s)
- Jiang Zhang
- School of Life Science, Central South University, Changsha, China
| | - Ming Chen
- Sanway Gene Technology Inc., Changsha, China
| | - Jiafeng Huang
- School of Life Science, Central South University, Changsha, China
| | - Xinwu Guo
- Sanway Gene Technology Inc., Changsha, China
| | - Yanjiao Zhang
- Shandong Province Key Laboratory of Applied Mycology, School of Life Sciences, Qingdao Agricultural University, Qingdao, China
| | - Dan Liu
- School of Life Science, Central South University, Changsha, China
| | - Ribang Wu
- School of Life Science, Central South University, Changsha, China
| | - Hailun He
- School of Life Science, Central South University, Changsha, China
- * E-mail: (HH); (GW)
| | - Jun Wang
- School of Life Science, Central South University, Changsha, China
- Sanway Gene Technology Inc., Changsha, China
- * E-mail: (HH); (GW)
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Untangling hidden nutrient dynamics: rapid ammonium cycling and single-cell ammonium assimilation in marine plankton communities. ISME JOURNAL 2019; 13:1960-1974. [PMID: 30911131 PMCID: PMC6776039 DOI: 10.1038/s41396-019-0386-z] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Revised: 02/25/2019] [Accepted: 02/27/2019] [Indexed: 11/30/2022]
Abstract
Ammonium is a central nutrient in aquatic systems. Yet, cell-specific ammonium assimilation among diverse functional plankton is poorly documented in field communities. Combining stable-isotope incubations (15N-ammonium, 15N2 and 13C-bicarbonate) with secondary-ion mass spectrometry, we quantified bulk ammonium dynamics, N2-fixation and carbon (C) fixation, as well as single-cell ammonium assimilation and C-fixation within plankton communities in nitrogen (N)-depleted surface waters during summer in the Baltic Sea. Ammonium production resulted from regenerated (≥91%) and new production (N2-fixation, ≤9%), supporting primary production by 78–97 and 2–16%, respectively. Ammonium was produced and consumed at balanced rates, and rapidly recycled within 1 h, as shown previously, facilitating an efficient ammonium transfer within plankton communities. N2-fixing cyanobacteria poorly assimilated ammonium, whereas heterotrophic bacteria and picocyanobacteria accounted for its highest consumption (~20 and ~20–40%, respectively). Surprisingly, ammonium assimilation and C-fixation were similarly fast for picocyanobacteria (non-N2-fixing Synechococcus) and large diatoms (Chaetoceros). Yet, the population biomass was high for Synechococcus but low for Chaetoceros. Hence, autotrophic picocyanobacteria and heterotrophic bacteria, with their high single-cell assimilation rates and dominating population biomass, competed for the same nutrient source and drove rapid ammonium dynamics in N-depleted marine waters.
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35
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Luedin SM, Storelli N, Danza F, Roman S, Wittwer M, Pothier JF, Tonolla M. Mixotrophic Growth Under Micro-Oxic Conditions in the Purple Sulfur Bacterium " Thiodictyon syntrophicum". Front Microbiol 2019; 10:384. [PMID: 30891015 PMCID: PMC6413534 DOI: 10.3389/fmicb.2019.00384] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Accepted: 02/13/2019] [Indexed: 12/23/2022] Open
Abstract
The microbial ecosystem of the meromictic Lake Cadagno (Ticino, Swiss Alps) has been studied intensively in order to understand structure and functioning of the anoxygenic phototrophic sulfur bacteria community living in the chemocline. It has been found that the purple sulfur bacterium "Thiodictyon syntrophicum" strain Cad16T, belonging to the Chromatiaceae, fixes around 26% of all bulk inorganic carbon in the chemocline, both during day and night. With this study, we elucidated for the first time the mode of carbon fixation of str. Cad16T under micro-oxic conditions with a combination of long-term monitoring of key physicochemical parameters with CTD, 14C-incorporation experiments and quantitative proteomics using in-situ dialysis bag incubations of str. Cad16T cultures. Regular vertical CTD profiling during the study period in summer 2017 revealed that the chemocline sank from 12 to 14 m which was accompanied by a bloom of cyanobacteria and the subsequent oxygenation of the deeper water column. Sampling was performed both day and night. CO2 assimilation rates were higher during the light period compared to those in the dark, both in the chemocline population and in the incubated cultures. The relative change in the proteome between day and night (663 quantified proteins) comprised only 1% of all proteins encoded in str. Cad16T. Oxidative respiration pathways were upregulated at light, whereas stress-related mechanisms prevailed during the night. These results indicate that low light availability and the co-occurring oxygenation of the chemocline induced mixotrophic growth in str. Cad16T. Our study thereby helps to further understand the consequences micro-oxic conditions for phototrophic sulfur oxidizing bacteria. The complete proteome data have been deposited to the ProteomeXchange database with identifier PXD010641.
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Affiliation(s)
- Samuel M. Luedin
- Microbiology Unit, Department of Botany and Plant Biology, University of Geneva, Geneva, Switzerland
- Laboratory of Applied Microbiology, Department of Environment, Constructions and Design, University of Applied Sciences of Southern Switzerland (SUPSI), Bellinzona, Switzerland
- Spiez Laboratory, Biology Division, Federal Office for Civil Protection, Spiez, Switzerland
| | - Nicola Storelli
- Laboratory of Applied Microbiology, Department of Environment, Constructions and Design, University of Applied Sciences of Southern Switzerland (SUPSI), Bellinzona, Switzerland
| | - Francesco Danza
- Microbiology Unit, Department of Botany and Plant Biology, University of Geneva, Geneva, Switzerland
- Laboratory of Applied Microbiology, Department of Environment, Constructions and Design, University of Applied Sciences of Southern Switzerland (SUPSI), Bellinzona, Switzerland
| | - Samuele Roman
- Laboratory of Applied Microbiology, Department of Environment, Constructions and Design, University of Applied Sciences of Southern Switzerland (SUPSI), Bellinzona, Switzerland
- Alpine Biology Center Foundation, Bellinzona, Switzerland
| | - Matthias Wittwer
- Spiez Laboratory, Biology Division, Federal Office for Civil Protection, Spiez, Switzerland
| | - Joël F. Pothier
- Environmental Genomics and System Biology Research Group, Institute of Natural Resource Sciences, Zurich University of Applied Sciences (ZHAW), Wädenswil, Switzerland
| | - Mauro Tonolla
- Microbiology Unit, Department of Botany and Plant Biology, University of Geneva, Geneva, Switzerland
- Laboratory of Applied Microbiology, Department of Environment, Constructions and Design, University of Applied Sciences of Southern Switzerland (SUPSI), Bellinzona, Switzerland
- Alpine Biology Center Foundation, Bellinzona, Switzerland
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36
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Leaf-Associated Shifts in Bacterial and Fungal Communities in Response to Chicken Rearing Under Moso Bamboo Forests in Subtropical China. FORESTS 2019. [DOI: 10.3390/f10030216] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Integrated bamboo-chicken farming (BCF) systems are a traditional agroforestry pattern with large economic benefits in subtropical China. However, little is known regarding the effect of this integration on the bamboo leaf-associated microbiome, which can be very important for disease control and nutrient turnover. In the present study, we compared the leaf-associated bacterial and fungal communities of moso bamboo (Phyllostachys edulis) in a BCF system and an adjacent moso bamboo forest (MBF). The results showed that Cyanobacteria and Ascomycota were the predominant microbial phyla associated with bamboo leaves. Chicken farming under the bamboo forest significantly increased the bacterial and fungal alpha diversity (observed operational taxonomic units (OTUs) and Simpson’s index) associated with bamboo leaves. Principal components analysis (PCoA) further confirmed the shifts in the bacterial and fungal communities caused by chicken farming. Based on the observed relative abundances, the phyla Bacteroidetes, Actinobacteria, TM7, and Basidiomycota were significantly increased on BCF-associated leaves compared with MBF leaves, while Acidobacteria and Ascomycota were significantly decreased. An ecological function prediction analysis based on metabolic processes indicated that BCF could accelerate nutrient (C, N, and S) cycling but may increase the risk of fungal-associated diseases. Our findings suggest that shifts in leaf-associated bacterial and fungal communities can be important indicators for the scientific management of BCF systems.
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Nitrate and ammonium fluxes to diatoms and dinoflagellates at a single cell level in mixed field communities in the sea. Sci Rep 2019; 9:1424. [PMID: 30723237 PMCID: PMC6363804 DOI: 10.1038/s41598-018-38059-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Accepted: 12/19/2018] [Indexed: 01/11/2023] Open
Abstract
Growth of large phytoplankton is considered to be diffusion limited at low nutrient concentrations, yet their constraints and contributions to carbon (C) and nitrogen fluxes in field plankton communities are poorly quantified under this condition. Using secondary ion mass spectrometry (SIMS), we quantified cell-specific assimilation rates of C, nitrate, and ammonium in summer communities of large phytoplankton when dissolved inorganic nitrogen concentrations are low in temperate coastal regions. Chain-forming diatoms composed 6% of total particulate organic carbon, but contributed 20% of C assimilation, 54% of nitrate assimilation and 32% of ammonium assimilation within the plankton community. In contrast, large dinoflagellates composed 11% of total POC, and contributed 14% of the C assimilation, 4% of ammonium and 9% of nitrate assimilation within the plankton community. Measured cell-specific C and nitrate assimilation rate match the Redfield ratio and the maximal nitrate assimilation in Chaetoceros spp. predicted by mass transfer theory. However, average ammonium assimilation rates were 30 and 340% higher than predicted by mass transfer theory in Tripos/Ceratium and Chaetoceros, respectively, suggesting that microbial interactions in the phycosphere may facilitate substantial luxury ammonium uptake by Chaetoceros in environments with fluctuating nitrate concentrations.
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38
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Schoffelen NJ, Mohr W, Ferdelman TG, Littmann S, Duerschlag J, Zubkov MV, Ploug H, Kuypers MMM. Single-cell imaging of phosphorus uptake shows that key harmful algae rely on different phosphorus sources for growth. Sci Rep 2018; 8:17182. [PMID: 30464246 PMCID: PMC6249326 DOI: 10.1038/s41598-018-35310-w] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Accepted: 11/02/2018] [Indexed: 12/04/2022] Open
Abstract
Single-cell measurements of biochemical processes have advanced our understanding of cellular physiology in individual microbes and microbial populations. Due to methodological limitations, little is known about single-cell phosphorus (P) uptake and its importance for microbial growth within mixed field populations. Here, we developed a nanometer-scale secondary ion mass spectrometry (nanoSIMS)-based approach to quantify single-cell P uptake in combination with cellular CO2 and N2 fixation. Applying this approach during a harmful algal bloom (HAB), we found that the toxin-producer Nodularia almost exclusively used phosphate for growth at very low phosphate concentrations in the Baltic Sea. In contrast, the non-toxic Aphanizomenon acquired only 15% of its cellular P-demand from phosphate and ~85% from organic P. When phosphate concentrations were raised, Nodularia thrived indicating that this toxin-producer directly benefits from phosphate inputs. The phosphate availability in the Baltic Sea is projected to rise and therefore might foster more frequent and intense Nodularia blooms with a concomitant rise in the overall toxicity of HABs in the Baltic Sea. With a projected increase in HABs worldwide, the capability to use organic P may be a critical factor that not only determines the microbial community structure, but the overall harmfulness and associated costs of algal blooms.
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Affiliation(s)
- Niels J Schoffelen
- Department of Biogeochemistry, Max Planck Institute for Marine Microbiology, Celsiusstraße 1, 28359, Bremen, Germany
| | - Wiebke Mohr
- Department of Biogeochemistry, Max Planck Institute for Marine Microbiology, Celsiusstraße 1, 28359, Bremen, Germany.
| | - Timothy G Ferdelman
- Department of Biogeochemistry, Max Planck Institute for Marine Microbiology, Celsiusstraße 1, 28359, Bremen, Germany
| | - Sten Littmann
- Department of Biogeochemistry, Max Planck Institute for Marine Microbiology, Celsiusstraße 1, 28359, Bremen, Germany
| | - Julia Duerschlag
- Department of Biogeochemistry, Max Planck Institute for Marine Microbiology, Celsiusstraße 1, 28359, Bremen, Germany
| | - Mikhail V Zubkov
- Ocean Biogeochemistry and Ecosystems, National Oceanography Centre Southampton, European Way, Southampton, SO14 3ZH, United Kingdom.,Scottish Association for Marine Science, Oban, Argyll PA37 1QA, Scotland, United Kingdom
| | - Helle Ploug
- Department of Marine Sciences, University of Gothenburg, Carl Skottsbergs Gata 22B, 41319, Gothenburg, Sweden
| | - Marcel M M Kuypers
- Department of Biogeochemistry, Max Planck Institute for Marine Microbiology, Celsiusstraße 1, 28359, Bremen, Germany
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Turbulence simultaneously stimulates small- and large-scale CO 2 sequestration by chain-forming diatoms in the sea. Nat Commun 2018; 9:3046. [PMID: 30076288 PMCID: PMC6076325 DOI: 10.1038/s41467-018-05149-w] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Accepted: 06/19/2018] [Indexed: 11/08/2022] Open
Abstract
Chain-forming diatoms are key CO2-fixing organisms in the ocean. Under turbulent conditions they form fast-sinking aggregates that are exported from the upper sunlit ocean to the ocean interior. A decade-old paradigm states that primary production in chain-forming diatoms is stimulated by turbulence. Yet, direct measurements of cell-specific primary production in individual field populations of chain-forming diatoms are poorly documented. Here we measured cell-specific carbon, nitrate and ammonium assimilation in two field populations of chain-forming diatoms (Skeletonema and Chaetoceros) at low-nutrient concentrations under still conditions and turbulent shear using secondary ion mass spectrometry combined with stable isotopic tracers and compared our data with those predicted by mass transfer theory. Turbulent shear significantly increases cell-specific C assimilation compared to still conditions in the cells/chains that also form fast-sinking, aggregates rich in carbon and ammonium. Thus, turbulence simultaneously stimulates small-scale biological CO2 assimilation and large-scale biogeochemical C and N cycles in the ocean. Chain-forming diatoms are key organisms in the biotic transfer of CO2 from the atmosphere to the ocean interior. Here, the authors show that turbulence stimulates and links small-scale and large scale processes from CO2 assimilation at a diatom cell level to nitrogen cycling in fast-sinking diatom aggregates.
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40
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Berner C, Bertos-Fortis M, Pinhassi J, Legrand C. Response of Microbial Communities to Changing Climate Conditions During Summer Cyanobacterial Blooms in the Baltic Sea. Front Microbiol 2018; 9:1562. [PMID: 30090087 PMCID: PMC6068395 DOI: 10.3389/fmicb.2018.01562] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2017] [Accepted: 06/25/2018] [Indexed: 11/13/2022] Open
Abstract
Frequencies and biomass of Baltic Sea cyanobacterial blooms are expected to be higher in future climate conditions, but also of longer duration as a result of increased sea surface temperature. Concurrently, climate predictions indicate a reduced salinity in the Baltic Sea. These climate-driven changes are expected to alter not solely the phytoplankton community but also the role of microbial communities for nutrient remineralization. Here, we present the response of summer plankton communities (filamentous cyanobacteria, picocyanobacteria, and heterotrophic bacteria) to the interplay of increasing temperature (from 16 to 18°C and 20°C) and reduced salinity (from salinity 6.9 to 5.9) in the Baltic Proper (NW Gotland Sea) using a microcosm approach. Warmer temperatures led to an earlier peak of cyanobacterial biomass, while yields were reduced. These conditions caused a decrease of nitrogen-fixers (Dolichospermum sp.) biomass, while non nitrogen-fixers (Pseudanabaena sp.) increased. Salinity reduction did not affect cyanobacterial growth nor community composition. Among heterotrophic bacteria, Actinobacteria showed preference for high temperature, while Gammaproteobacteria thrived at in situ temperature. Heterotrophic bacteria community changed drastically at lower salinity and resembled communities at high temperature. Picocyanobacteria and heterotrophic bacterial biomass had a pronounced increase associated with the decay of filamentous cyanobacteria. This suggests that shifts in community composition of heterotrophic bacteria are influenced both directly by abiotic factors (temperature and salinity) and potentially indirectly by cyanobacteria. Our findings suggest that at warmer temperature, lower yield of photosynthetic cyanobacteria combined with lower proportion of nitrogen-fixers in the community could result in lower carbon export to the marine food web with consequences for the decomposer community of heterotrophic bacteria.
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Affiliation(s)
- Christoffer Berner
- Department of Biology and Environmental Science, Centre for Ecology and Evolution in Microbial Model Systems (EEMiS), Linnaeus University, Kalmar, Sweden
| | - Mireia Bertos-Fortis
- Department of Biology and Environmental Science, Centre for Ecology and Evolution in Microbial Model Systems (EEMiS), Linnaeus University, Kalmar, Sweden
| | - Jarone Pinhassi
- Department of Biology and Environmental Science, Centre for Ecology and Evolution in Microbial Model Systems (EEMiS), Linnaeus University, Kalmar, Sweden
| | - Catherine Legrand
- Department of Biology and Environmental Science, Centre for Ecology and Evolution in Microbial Model Systems (EEMiS), Linnaeus University, Kalmar, Sweden
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Teikari JE, Fewer DP, Shrestha R, Hou S, Leikoski N, Mäkelä M, Simojoki A, Hess WR, Sivonen K. Strains of the toxic and bloom-forming Nodularia spumigena (cyanobacteria) can degrade methylphosphonate and release methane. THE ISME JOURNAL 2018; 12:1619-1630. [PMID: 29445131 PMCID: PMC5955973 DOI: 10.1038/s41396-018-0056-6] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Revised: 01/08/2018] [Accepted: 01/10/2018] [Indexed: 11/10/2022]
Abstract
Nodularia spumigena is a nitrogen-fixing cyanobacterium that forms toxic blooms in the Baltic Sea each summer and the availability of phosphorous is an important factor limiting the formation of these blooms. Bioinformatic analysis identified a phosphonate degrading (phn) gene cluster in the genome of N. spumigena suggesting that this bacterium may use phosphonates as a phosphorus source. Our results show that strains of N. spumigena could grow in medium containing methylphosphonic acid (MPn) as the sole source of phosphorous and released methane when growing in medium containing MPn. We analyzed the total transcriptomes of N. spumigena UHCC 0039 grown using MPn and compared them with cultures growing in Pi-replete medium. The phnJ, phosphonate lyase gene, was upregulated when MPn was the sole source of phosphorus, suggesting that the expression of this gene could be used to indicate the presence of bioavailable phosphonates. Otherwise, growth on MPn resulted in only a minor reconstruction of the transcriptome and enabled good growth. However, N. spumigena strains were not able to utilize any of the anthropogenic phosphonates tested. The phosphonate utilizing pathway may offer N. spumigena a competitive advantage in the Pi-limited cyanobacterial blooms of the Baltic Sea.
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Affiliation(s)
- Jonna E Teikari
- Department of Microbiology, University of Helsinki, Viikinkaari 9, Helsinki, FI-00014, Finland
| | - David P Fewer
- Department of Microbiology, University of Helsinki, Viikinkaari 9, Helsinki, FI-00014, Finland
| | - Rashmi Shrestha
- Department of Microbiology, University of Helsinki, Viikinkaari 9, Helsinki, FI-00014, Finland
| | - Shengwei Hou
- Genetics and Experimental Bioinformatics, Institute of Biology III, University Freiburg, Schänzlestraße 1, Freiburg, D-79104, Germany
| | - Niina Leikoski
- Department of Microbiology, University of Helsinki, Viikinkaari 9, Helsinki, FI-00014, Finland
| | - Minna Mäkelä
- Department of Agricultural Sciences, University of Helsinki, Viikinkaari 9, Helsinki, FI-00014, Finland
| | - Asko Simojoki
- Department of Agricultural Sciences, University of Helsinki, Viikinkaari 9, Helsinki, FI-00014, Finland
| | - Wolfgang R Hess
- Genetics and Experimental Bioinformatics, Institute of Biology III, University Freiburg, Schänzlestraße 1, Freiburg, D-79104, Germany
| | - Kaarina Sivonen
- Department of Microbiology, University of Helsinki, Viikinkaari 9, Helsinki, FI-00014, Finland.
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42
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Wulff A, Karlberg M, Olofsson M, Torstensson A, Riemann L, Steinhoff FS, Mohlin M, Ekstrand N, Chierici M. Ocean acidification and desalination: climate-driven change in a Baltic Sea summer microplanktonic community. MARINE BIOLOGY 2018; 165:63. [PMID: 29563649 PMCID: PMC5843668 DOI: 10.1007/s00227-018-3321-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Accepted: 03/01/2018] [Indexed: 05/19/2023]
Abstract
Helcom scenario modelling suggests that the Baltic Sea, one of the largest brackish-water bodies in the world, could expect increased precipitation (decreased salinity) and increased concentration of atmospheric CO2 over the next 100 years. These changes are expected to affect the microplanktonic food web, and thereby nutrient and carbon cycling, in a complex and possibly synergistic manner. In the Baltic Proper, the extensive summer blooms dominated by the filamentous cyanobacteria Aphanizomenon sp., Dolichospermum spp. and the toxic Nodularia spumigena contribute up to 30% of the yearly new nitrogen and carbon exported to the sediment. In a 12 days outdoor microcosm experiment, we tested the combined effects of decreased salinity (from 6 to 3) and elevated CO2 concentrations (380 and 960 µatm) on a natural summer microplanktonic community, focusing on diazotrophic filamentous cyanobacteria. Elevated pCO2 had no significant effects on the natural microplanktonic community except for higher biovolume of Dolichospermum spp. and lower biomass of heterotrophic bacteria. At the end of the experimental period, heterotrophic bacterial abundance was correlated to the biovolume of N. spumigena. Lower salinity significantly affected cyanobacteria together with biovolumes of dinoflagellates, diatoms, ciliates and heterotrophic bacteria, with higher biovolume of Dolichospermum spp. and lower biovolume of N. spumigena, dinoflagellates, diatoms, ciliates and heterotrophic bacteria in reduced salinity. Although the salinity effects on diatoms were apparent, they could not clearly be separated from the influence of inorganic nutrients. We found a clear diurnal cycle in photosynthetic activity and pH, but without significant treatment effects. The same diurnal pattern was also observed in situ (pCO2, pH). Thus, considering the Baltic Proper, we do not expect any dramatic effects of increased pCO2 in combination with decreased salinity on the microplanktonic food web. However, long-term effects of the experimental treatments need to be further studied, and indirect effects of the lower salinity treatments could not be ruled out. Our study adds one piece to the complicated puzzle to reveal the combined effects of increased pCO2 and reduced salinity levels on the Baltic microplanktonic community.
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Affiliation(s)
- Angela Wulff
- Department of Biological and Environmental Sciences, University of Gothenburg, Box 461, 405 30 Göteborg, Sweden
| | - Maria Karlberg
- Department of Biological and Environmental Sciences, University of Gothenburg, Box 461, 405 30 Göteborg, Sweden
| | - Malin Olofsson
- Department of Marine Sciences, University of Gothenburg, Box 461, 405 30 Göteborg, Sweden
| | - Anders Torstensson
- Department of Biological and Environmental Sciences, University of Gothenburg, Box 461, 405 30 Göteborg, Sweden
- Present Address: School of Oceanography, University of Washington, Box 357940, Seattle, WA 98195 USA
| | - Lasse Riemann
- Department of Biology, Marine Biological Section, University of Copenhagen, Strandpromenaden 5, 3000 Helsingør, Denmark
| | - Franciska S. Steinhoff
- Department of Biological and Environmental Sciences, University of Gothenburg, Box 461, 405 30 Göteborg, Sweden
| | - Malin Mohlin
- Swedish Meteorological and Hydrological Institute, Sven Källfelts gata 15, 426 71 Västra Frölunda, Sweden
| | - Nina Ekstrand
- Department of Marine Sciences, University of Gothenburg, Box 461, 405 30 Göteborg, Sweden
| | - Melissa Chierici
- Department of Marine Sciences, University of Gothenburg, Box 461, 405 30 Göteborg, Sweden
- Present Address: Institute of Marine Research, Sykehusveien 23, Tromsø, Norway
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Liang Y, Zhang Y, Wang N, Luo T, Zhang Y, Rivkin RB. Estimating Primary Production of Picophytoplankton Using the Carbon-Based Ocean Productivity Model: A Preliminary Study. Front Microbiol 2017; 8:1926. [PMID: 29051755 PMCID: PMC5633608 DOI: 10.3389/fmicb.2017.01926] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Accepted: 09/21/2017] [Indexed: 11/13/2022] Open
Abstract
Picophytoplankton are acknowledged to contribute significantly to primary production (PP) in the ocean while now the method to measure PP of picophytoplankton (PPPico) at large scales is not yet well established. Although the traditional 14C method and new technologies based on the use of stable isotopes (e.g., 13C) can be employed to accurately measure in situ PPPico, the time-consuming and labor-intensive shortage of these methods constrain their application in a survey on large spatiotemporal scales. To overcome this shortage, a modified carbon-based ocean productivity model (CbPM) is proposed for estimating the PPPico whose principle is based on the group-specific abundance, cellular carbon conversion factor (CCF), and temperature-derived growth rate of picophytoplankton. Comparative analysis showed that the estimated PPPico using CbPM method is significantly and positively related (r2 = 0.53, P < 0.001, n = 171) to the measured 14C uptake. This significant relationship suggests that CbPM has the potential to estimate the PPPico over large spatial and temporal scales. Currently this model application may be limited by the use of invariant cellular CCF and the relatively small data sets to validate the model which may introduce some uncertainties and biases. Model performance will be improved by the use of variable conversion factors and the larger data sets representing diverse growth conditions. Finally, we apply the CbPM-based model on the collected data during four cruises in the Bohai Sea in 2005. Model-estimated PPPico ranged from 0.1 to 11.9, 29.9 to 432.8, 5.5 to 214.9, and 2.4 to 65.8 mg C m-2 d-1 during March, June, September, and December, respectively. This study shed light on the estimation of global PPPico using carbon-based production model.
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Affiliation(s)
- Yantao Liang
- Research Center for Marine Biology and Carbon Sequestration, Shandong Provincial Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China.,Institute of Marine Microbes and Ecospheres, State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, China
| | - Yongyu Zhang
- Research Center for Marine Biology and Carbon Sequestration, Shandong Provincial Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China
| | - Nannan Wang
- Institute of Marine Microbes and Ecospheres, State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, China
| | - Tingwei Luo
- Institute of Marine Microbes and Ecospheres, State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, China
| | - Yao Zhang
- Institute of Marine Microbes and Ecospheres, State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, China
| | - Richard B Rivkin
- Department of Ocean Sciences, Memorial University of Newfoundland, St. John's, NL, Canada
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