18 results on '"Grossart, Hans-Peter"'
Search Results
2. Flexible habitat choice of pelagic bacteria increases system stability and energy flow through the microbial loop
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Villalba, Luis Alberto, Karnatak, Rajat, Grossart, Hans‐Peter, Wollrab, Sabine, and 1 Leibniz Institut of Freshwater Ecology and Inland Fisheries (IGB) Berlin Germany
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ddc:579.3 ,Aquatic Science ,Oceanography - Abstract
Pelagic bacteria can be classified into free‐living and particle‐attached life modes, which either dwell in the water column or attach to suspended particles. Bacteria with a generalist life style, however, can actively shift between these two habitats. Globally increasing densities of natural and artificial particles enhance habitat heterogeneity, with potential consequences for system stability and trophic transfer through aquatic food webs. To better decipher the dynamics of microbial communities, we investigated the influence of adaptive vs. fixed habitat choice on species coexistence for a simplified bacterial community by analyzing a corresponding food web model, consisting of two specialist bacterial prey species (free and attached), a generalist bacterial prey species with the ability to shift between both habitats, and two protist predators, specialized on either water or particle compartment. For simplicity we assume a shared resource pool, considering particles only for colonization but not as a source for nutrients or carbon, that is, inert particles like microplastics or inorganic sediments. The model predicts coexistence on a cyclic attractor between fixed and flexible bacteria, if the costs for adaptive habitat choice can be balanced by adaptation speed. The presence of adaptive prey dampens predator–prey cycle amplitudes, contributing to system stabilization resulting in higher mean predator biomass compared to specialist prey only. Thus, in pelagic microbial systems, flexible habitat choice at the prey level has important implications for system stability and magnitude of energy flow through the microbial loop., German Ministry of Education and Science, German Science Foundation (DFG)
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- 2022
3. Postglacial adaptations enabled colonization and quasi-clonal dispersal of ammonia-oxidizing archaea in modern European large lakes
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Ngugi, David Kamanda, Salcher, Michaela M, Andrei, Adrian-Stefan, Ghai, Rohit, Klotz, Franziska, Chiriac, Maria-Cecilia, Ionescu, Danny, Büsing, Petra, Grossart, Hans-Peter, Xing, Peng, Priscu, John C, Alymkulov, Salmor, Pester, Michael, University of Zurich, and Ngugi, David Kamanda
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1000 Multidisciplinary ,Multidisciplinary ,10126 Department of Plant and Microbial Biology ,580 Plants (Botany) ,10211 Zurich-Basel Plant Science Center - Abstract
Ammonia-oxidizing archaea (AOA) play a key role in the aquatic nitrogen cycle. Their genetic diversity is viewed as the outcome of evolutionary processes that shaped ancestral transition from terrestrial to marine habitats. However, current genome-wide insights into AOA evolution rarely consider brackish and freshwater representatives or provide their divergence timeline in lacustrine systems. An unbiased global assessment of lacustrine AOA diversity is critical for understanding their origins, dispersal mechanisms, and ecosystem roles. Here, we leveraged continental-scale metagenomics to document that AOA species diversity in freshwater systems is remarkably low compared to marine environments. We show that the uncultured freshwater AOA, “ Candidatus Nitrosopumilus limneticus,” is ubiquitous and genotypically static in various large European lakes where it evolved 13 million years ago. We find that extensive proteome remodeling was a key innovation for freshwater colonization of AOA. These findings reveal the genetic diversity and adaptive mechanisms of a keystone species that has survived clonally in lakes for millennia.
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- 2023
4. Scoping Review Protocol: What characterizes an urban lake and how might the challenges differ across climate and urbanization gradients?
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Kocher, Megan, Gorsky, Adrianna, Neumiller, Grace, Brighenti, Ludmila, Melles, Stephanie, Costadone, Laura, Kelly, Patrick, Brentrup, Jennie, Hoffman, Katie, Holgerson, Meredith, Finlay, Jacques, Bruel, Rosalie, Grossart, Hans-Peter, and Lewis, Abigail
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Life Sciences - Abstract
Scoping review protocol
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- 2022
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5. Oxic methane production in aquatic systems: do we need to care about?
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Grossart, Hans-Peter
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Speaker presentation
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- 2022
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6. Antarctic Glacial Meltwater Impacts the Diversity of Fungal Parasites Associated With Benthic Diatoms in Shallow Coastal Zones
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Ilicic, Doris, Woodhouse, Jason, Karsten, Ulf, Zimmermann, Jonas, Wichard, Thomas, Quartino, Maria Liliana, Campana, Gabriela Laura, Livenets, Alexandra, Van den Wyngaert, Silke, and Grossart, Hans-Peter
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Microbiology (medical) ,fungi ,500 Naturwissenschaften und Mathematik::570 Biowissenschaften ,Biologie::570 Biowissenschaften ,Biologie ,Microbiology ,salinity gradient ,Chytridiomycota ,ddc:570 ,phytoplankton host ,aquatic fungi ,Antarctica ,Institut für Biochemie und Biologie ,570 Biowissenschaften ,Illumina amplicon sequencing ,Carlini Station - Abstract
Aquatic ecosystems are frequently overlooked as fungal habitats, although there is increasing evidence that their diversity and ecological importance are greater than previously considered. Aquatic fungi are critical and abundant components of nutrient cycling and food web dynamics, e.g., exerting top-down control on phytoplankton communities and forming symbioses with many marine microorganisms. However, their relevance for microphytobenthic communities is almost unexplored. In the light of global warming, polar regions face extreme changes in abiotic factors with a severe impact on biodiversity and ecosystem functioning. Therefore, this study aimed to describe, for the first time, fungal diversity in Antarctic benthic habitats along the salinity gradient and to determine the co-occurrence of fungal parasites with their algal hosts, which were dominated by benthic diatoms. Our results reveal that Ascomycota and Chytridiomycota are the most abundant fungal taxa in these habitats. We show that also in Antarctic waters, salinity has a major impact on shaping not just fungal but rather the whole eukaryotic community composition, with a diversity of aquatic fungi increasing as salinity decreases. Moreover, we determined correlations between putative fungal parasites and potential benthic diatom hosts, highlighting the need for further systematic analysis of fungal diversity along with studies on taxonomy and ecological roles of Chytridiomycota., Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe; 1290
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- 2022
7. Additional file 2 of Frequency of occurrence and habitat selection shape the spatial variation in the antibiotic resistome in riverine ecosystems in eastern China
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Jiang, Chunxia, Chen, Haiyang, Grossart, Hans-Peter, Zhang, Quanfa, Stoks, Robby, Zhao, Yi, Ju, Feng, Liu, Wenzhi, and Yang, Yuyi
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Additional file 2: Fig. S1Number (a) and relative abundance (b) of ARGs detected inriverine ecosystems of eastern China. R represents rhizosphere soil; SBrepresents surface bulk soil (0-20 cm below bulk soil surface); BB represents bottombulk soil (40-60 cm below bulk soil surface); S represents sediment (0-20 cmbelow sediment surface); SR and NR represent rhizosphere soil in the south andnorth, respectively; SSB and NSB represent surface bulk soil (0-20 cm belowbulk soil surface) in the south and north, respectively; SBB and NBB represent bottombulk soil (40-60 cm below bulk soil surface) in the south and north,respectively; SS and NS represent sediment (0-20 cm below sediment surface) inthe south and north, respectively. MLS representmacrolides-lincosamides-streptogramines. Fig.S2. Proportion of detected ARGsin terms of number (a) and relative abundance (b). (Forabbreviations, see legend of Fig. S1). Fig. S3. Relative abundance ofcore ARGs in the riverine ecosystems of eastern China. (For abbreviations, seelegend of Fig. S1). Fig. S3. Relative abundance of core ARGs in the riverineecosystems of eastern China. (For abbreviations, see legend of Fig. S1). Fig.S4. The standard deviation of ARG abundance (a) and subtype number (b)in the riverine ecosystems of eastern China. (For abbreviations, see legend ofFig. S1). Fig.S5. Proportion of detected ARGs (number (a) and abundance (b)) in different habitats in the riverine ecosystem of easternChina. (For abbreviations, see legend of Fig. S1). Fig. S6. Influence of vegetation richness, coverage and plant biomasson ARG abundance. (For abbreviations, see legend of Fig. S1). Fig. S7. SPEC-OCCU plots showing ARGs that differ between two defined groups (i.e. SR vs. SSB&SBB, NR vs. NSB&NBB); the x-axis represents occupancy, i.e. how well an ARG is distributed across all sites of each group; and the y-axis represents specificity, i.e. whether ARGs are also found in other groups. (For abbreviations, see legend of Fig. S1).Fig. S8. RDA of ARGs and physiochemical variables controlling ARGs in different habitats (rhizosphere (R), surface bulk soil (SB), bottom bulk soil (BB), and sediment (S)). Note: *0.01 < P < 0.05, **P < 0.01. (For abbreviations, see legend of Fig. S1). Fig. S9. Network diagrams showing the correlation of individual ARGs and individual parameters in the different habitats. Blue and red lines represent negative and positive relationships, respectively (ρ > 0.8 or ρ < -0.8, P > 0.01). (The complement of Fig. 7). (For abbreviations, see legend of Fig. S1).
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- 2022
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8. A novel measurement-based model for calculating O2 flux at interfaces in aquatic environments
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Moradi, Nasrollah, Klawonn, Isabell, Iversen, Morten, Grossart, Hans-Peter, Ploug, Helle, Fischer, Gerhard, Wenzhöfer, Frank, and Khalili, Arzhang
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- 2021
9. A Salinity Threshold Separating Fungal Communities in the Baltic Sea
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Rojas-Jimenez, Keilor, Rieck, Angelika, Wurzbacher, Christian, Jürgens, Klaus, Labrenz, Matthias, and Grossart, Hans-Peter
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ddc - Published
- 2018
10. Environmental control on microbial turnover of leaf carbon in streams - ecological function of phototrophic-heterotrophic interactions
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Fabian, Jenny, Zlatanović, Sanja, Mutz, Michael, Grossart, Hans-Peter, Geldern, Robert van, Ulrich, Andreas, Gleixner, Gerd, and Premke, Katrin
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light ,microbial interactions ,algae ,streambed structure ,PLFA ,bacteria ,terrestrial carbon ,13C stable isotopes - Abstract
In aquatic ecosystems, light availability can significantly influence microbial turnover of terrestrial organic matter through associated metabolic interactions between phototrophic and heterotrophic communities. However, particularly in streams, microbial functions vary significantly with the structure of the streambed, that is the distribution and spatial arrangement of sediment grains in the streambed. It is therefore essential to elucidate how environmental factors synergistically define the microbial turnover of terrestrial organic matter in order to better understand the ecological role of photo-heterotrophic interactions in stream ecosystem processes. In outdoor experimental streams, we examined how the structure of streambeds modifies the influence of light availability on microbial turnover of leaf carbon (C). Furthermore, we investigated whether the studied relationships of microbial leaf C turnover to environmental conditions are affected by flow intermittency commonly occurring in streams. We applied leaves enriched with a 13C-stable isotope tracer and combined quantitative and isotope analyses. We thereby elucidated whether treatment induced changes in C turnover were associated with altered use of leaf C within the microbial food web. Moreover, isotope analyses were combined with measurements of microbial community composition to determine whether changes in community function were associated with a change in community composition. In this study, we present evidence, that environmental factors interactively determine how phototrophs and heterotrophs contribute to leaf C turnover. Light availability promoted the utilization of leaf C within the microbial food web, which was likely associated with a promoted availability of highly bioavailable metabolites of phototrophic origin. However, our results additionally confirm that the structure of the streambed modifies light-related changes in microbial C turnover. From our observations, we conclude that the streambed structure influences the strength of photo-heterotrophic interactions by defining the spatial availability of algal metabolites in the streambed and the composition of microbial communities. Collectively, our multifactorial approach provides valuable insights into environmental controls on the functioning of stream ecosystems., Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe, 693
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- 2018
11. Data Descriptor : A European Multi Lake Survey dataset of environmental variables, phytoplankton pigments and cyanotoxins
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Mantzouki, Evanthia, Campbell, James, Loon, Emiel van, Visser, Petra, Konstantinou, Iosif, Antoniou, Maria G., Giuliani, Grégory, Machado-Vieira, Danielle, Oliveira, Alinne Gurjão de, Maronić, Dubravka Špoljarić, Stević, Filip, Fakioglu, Özden, Soylu, Elif Neyran, Yağcı, Meral Apaydın, Çınar, Şakir, Çapkın, Kadir, Yağcı, Abdulkadir, Cesur, Mehmet, Bilgin, Fuat, Bulut, Cafer, Fránková, Markéta, Vasconcelos, Vitor, Uysal, Rahmi, Köker, Latife, Akçaalan, Reyhan, Albay, Meriç, Alp, Mehmet Tahir, Özkan, Korhan, Sevindik, Tuğba Ongun, Tunca, Hatice, Önem, Burçin, Richardson, Jessica, Morais, João, Christoffersen, Kirsten Seestern, Edwards, Christine, Bergkemper, Victoria, O'Leary, Sarah, Beirne, Eilish, Cromie, Hannah, Ibelings, Bastiaan W., Warming, Trine Perlt, Feldmann, Tõnu, Laas, Alo, Vale, Micaela, Panksep, Kristel, Tuvikene, Lea, Kangro, Kersti, Häggqvist, Kerstin, Salmi, Pauliina, Arvola, Lauri, Fastner, Jutta, Straile, Dietmar, Rothhaupt, Karl-Otto, Fonvielle, Jeremy, Raposeiro, Pedro M., Grossart, Hans-Peter, Avagianos, Christos, Kaloudis, Triantafyllos, Triantis, Theodoros, Zervou, Sevasti-Kiriaki, Hiskia, Anastasia, Gkelis, Spyros, Panou, Manthos, McCarthy, Valerie, Perello, Victor C., Gonçalves, Vítor Manuel da Costa, Obertegger, Ulrike, Boscaini, Adriano, Flaim, Giovanna, Salmaso, Nico, Cerasino, Leonardo, Koreivienė, Judita, Karosienė, Jūratė, Kasperovičienė, Jūratė, Savadova, Ksenija, Vitonytė, Irma, Aleksovski, Boris, Haande, Sigrid, Skjelbred, Birger, Grabowska, Magdalena, Karpowicz, Maciej, Chmura, Damian, Nawrocka, Lidia, Kobos, Justyna, Mazur-Marzec, Hanna, Alcaraz-Párraga, Pablo, Wilk-Woźniak, Elżbieta, Krstić, Svetislav, Krztoń, Wojciech, Walusiak, Edward, Gagala, Ilona, Mankiewicz-Boczek, Joana, Toporowska, Magdalena, Pawlik-Skowronska, Barbara, Niedźwiecki, Michał, Pęczuła, Wojciech, Napiórkowska-Krzebietke, Agnieszka, Dunalska, Julita, Nemova, Hana, Sieńska, Justyna, Szymański, Daniel, Kruk, Marek, Budzyńska, Agnieszka, Goldyn, Ryszard, Kozak, Anna, Rosińska, Joanna, Szeląg-Wasielewska, Elżbieta, Domek, Piotr, Jakubowska-Krepska, Natalia, Drastichova, Iveta, Kwasizur, Kinga, Messyasz, Beata, Pełechata, Aleksandra, Pełechaty, Mariusz, Kokocinski, Mikolaj, Madrecka, Beata, Kostrzewska-Szlakowska, Iwona, Frąk, Magdalena, Bańkowska-Sobczak, Agnieszka, Wasilewicz, Michał, Chomova, Lucia, Ochocka, Agnieszka, Pasztaleniec, Agnieszka, Jasser, Iwona, Geraldes, Ana Maria, Leira, Manel, Hernández, Armand, Pfeiffer, Tanja Žuna, Remec-Rekar, Spela, Elersek, Tina, Delgado-Martín, Jordi, García, David, Cereijo, Jose Luís, Gomà, Joan, Trapote, Mari Carmen, Vegas-Vilarrúbia, Teresa, Obrador, Biel, García-Murcia, Ana, Vucelić, Itana Bokan, Real, Monserrat, Romans, Elvira, Noguero-Ribes, Jordi, Duque, David Parreño, Fernández-Morán, Elísabeth, Úbeda, Bárbara, Gálvez, José Ángel, Marcé, Rafael, Catalán, Núria, Pérez-Martínez, Carmen, Žutinić, Petar, Ramos-Rodríguez, Eloísa, Cillero-Castro, Carmen, Moreno-Ostos, Enrique, Blanco, José María, Rodríguez, Valeriano, Montes-Pérez, Jorge Juan, Palomino, Roberto L., Rodríguez-Pérez, Estela, Carballeira, Rafael, Camacho, Antonio, Udovič, Marija Gligora, Picazo, Antonio, Rochera, Carlos, Santamans, Anna C., Ferriol, Carmen, Romo, Susana, Soria, Juan Miguel, Hansson, Lars-Anders, Urrutia-Cordero, Pablo, Özen, Arda, Bravo, Andrea G., Plenković-Moraj, Anđelka, Buck, Moritz, Colom-Montero, William, Mustonen, Kristiina, Pierson, Don, Yang, Yang, Verspagen, Jolanda M.H., Domis, Lisette N. de Senerpont, Seelen, Laura, Teurlincx, Sven, Verstijnen, Yvon, Tsiarta, Nikoletta, Lürling, Miquel, Maliaka, Valentini, Faassen, Elisabeth J., Latour, Delphine, Carey, Cayelan C., Paerl, Hans W., Torokne, Andrea, Karan, Tünay, Demir, Nilsun, Beklioğlu, Meryem, Bláha, Luděk, Filiz, Nur, Levi, Eti E., Iskin, Uğur, Bezirci, Gizem, Tavşanoğlu, Ülkü Nihan, Çelik, Kemal, Özhan, Koray, Karakaya, Nusret, Koçer, Mehmet Ali Turan, Yilmaz, Mete, Geriš, Rodan, Maraşlıoğlu, Faruk, and Institute of Agricultural and Environmental Sciences
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Europe ,ddc:570 ,Settore BIO/07 - ECOLOGIA ,datasets ,lakes ,articles ,Phytoplankton pigments ,Institut für Biochemie und Biologie ,Dataset - Abstract
Under ongoing climate change and increasing anthropogenic activity, which continuously challenge ecosystem resilience, an in-depth understanding of ecological processes is urgently needed. Lakes, as providers of numerous ecosystem services, face multiple stressors that threaten their functioning. Harmful cyanobacterial blooms are a persistent problem resulting from nutrient pollution and climate-change induced stressors, like poor transparency, increased water temperature and enhanced stratification. Consistency in data collection and analysis methods is necessary to achieve fully comparable datasets and for statistical validity, avoiding issues linked to disparate data sources. The European Multi Lake Survey (EMLS) in summer 2015 was an initiative among scientists from 27 countries to collect and analyse lake physical, chemical and biological variables in a fully standardized manner. This database includes in-situ lake variables along with nutrient, pigment and cyanotoxin data of 369 lakes in Europe, which were centrally analysed in dedicated laboratories. Publishing the EMLS methods and dataset might inspire similar initiatives to study across large geographic areas that will contribute to better understanding lake responses in a changing environment. The authors acknowledge COST Action ES 1105 “CYANOCOST – Cyanobacterial blooms and toxins in water resources: Occurrence impacts and management” and COST Action ES 1201 “NETLAKE – Networking Lake Observatories in Europe” for contributing to this study through networking and knowledge sharing with European experts in the field. Evanthia Mantzouki was supported by a grant from the Swiss State Secretariat for Education, Research and Innovation (SERI) to Bas Ibelings and by supplementary funding from University of Geneva. We thank Wendy Beekman for the nutrient analysis and the University of Wageningen for covering the costs of this analysis from the personal funding of dr. Miquel Lürling. We thank Pieter Slot for assisting with the pigment analysis and the University of Amsterdam for covering the costs of the analysis through funding from the group of Prof. Jef Huisman and dr. Petra Visser (IBED). We would like to thank the Environmental Data Initiative for covering the cost of archiving the EMLS dataset. We would like to thank the Leibniz Institute of Freshwater Ecology and Inland Fisheries, Dept. of Experimental Limnology and the Aquatic Microbial Ecology Group for logistic and technical support of J. Fonvielle and H.-P. Grossart; and the Leibniz Association for financial support. The collection of data for Lough Erne and Lough Neagh were funded by the Department of Agriculture, Environment and Rural Affairs, Northern Ireland. The authors acknowledge COST Action ES 1105 “CYANOCOST – Cyanobacterial blooms and toxins in water resources: Occurrence impacts and management” and COST Action ES 1201 “NETLAKE – Networking Lake Observatories in Europe” for contributing to this study through networking and knowledge sharing with European experts in the field. Evanthia Mantzouki was supported by a grant from the Swiss State Secretariat for Education, Research and Innovation (SERI) to Bas Ibelings and by supplementary funding from University of Geneva. We thank Wendy Beekman for the nutrient analysis and the University of Wageningen for covering the costs of this analysis from the personal funding of dr. Miquel Lürling. We thank Pieter Slot for assisting with the pigment analysis and the University of Amsterdam for covering the costs of the analysis through funding from the group of Prof. Jef Huisman and dr. Petra Visser (IBED). We would like to thank the Environmental Data Initiative for covering the cost of archiving the EMLS dataset. We would like to thank the Leibniz Institute of Freshwater Ecology and Inland Fisheries, Dept. of Experimental Limnology and the Aquatic Microbial Ecology Group for logistic and technical support of J. Fonvielle and H.-P. Grossart; and the Leibniz Association for financial support. The collection of data for Lough Erne and Lough Neagh were funded by the Department of Agriculture, Environment and Rural Affairs, Northern Ireland.
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- 2018
12. A fast and sensitive method for the continuous in situ determination of dissolved methane and its d13C-isotope ratio in surface waters
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Hartmann, Jan F., Gentz, Torben, Schiller, Amanada, Greule, Markus, Grossart, Hans-Peter, Ionescu, Danny, Keppler, Frank, Martinez-Cruz, Karla, Sepulveda-Jauregui, A., and Isenbeck-Schröter, Margot
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A fast and sensitive method for the continuous determination of methane (CH4) and its stable carbon isotopic values (d13C-CH4) in surface waters was developed by applying a vacuum to a gas/liquid exchange membrane and measuring the extracted gases by a portable cavity ring-down spectroscopy analyser (M-CRDS). The M-CRDS was calibrated and characterized for CH4 concentration and d13C-CH4 with synthetic water standards. The detection limit of the M-CRDS for the simultaneous determination of CH4 and d13CCH4 is 3.6 nmol L21 CH4. A measurement precision of CH4 concentrations and d13C-CH4 in the range of 1.1%, respectively, 1.7& (1r) and accuracy (1.3%, respectively, 0.8& [1r]) was achieved for single measurements and averaging times of 10 min. The response time s of 5765 s allow determination of d13C-CH4 values more than twice as fast than other methods. The demonstrated M-CRDS method was applied and tested for Lake Stechlin (Germany) and compared with the headspace-gas chromatography and fast membrane CH4 concentration methods. Maximum CH4 concentrations (577 nmol L21) and lightest d13C-CH4 (235.2&) were found around the thermocline in depth profile measurements. The M-CRDS-method was in good agreement with other methods. Temporal variations in CH4 concentration and d13C-CH4 obtained in 24 h measurements indicate either local methane production/oxidation or physical variations in the thermocline. Therefore, these results illustrate the need of fast and sensitive analyses to achieve a better understanding of different mechanisms and pathways of CH4 formation in aquatic environments.
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- 2018
13. Integrating chytrid fungal parasites into plankton ecology: research gaps and needs
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Frenken, Thijs, Wolinska, Justyna, Alacid, Elisabet, Berger, Stella A., Bourne, Elizabeth C., Gerphagnon, Mélanie, Grossart, Hans-Peter, Gsell, Alena S., Ibelings, Bas W., and Kagami, Maiko [u.v.m.]
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research gaps ,fungi ,chytrid fungal parasites ,plankton ecology ,500 Naturwissenschaften und Mathematik::590 Tiere (Zoologie)::590 Tiere (Zoologie) - Abstract
Chytridiomycota, often referred to as chytrids, can be virulent parasites with the potential to inflict mass mortalities on hosts, causing e.g. changes in phytoplankton size distributions and succession, and the delay or suppression of bloom events. Molecular environmental surveys have revealed an unexpectedly large diversity of chytrids across a wide range of aquatic ecosystems worldwide. As a result, scientific interest towards fungal parasites of phytoplankton has been gaining momentum in the past few years. Yet, we still know little about the ecology of chytrids, their life cycles, phylogeny, host specificity and range. Information on the contribution of chytrids to trophic interactions, as well as co‐evolutionary feedbacks of fungal parasitism on host populations is also limited. This paper synthesizes ideas stressing the multifaceted biological relevance of phytoplankton chytridiomycosis, resulting from discussions among an international team of chytrid researchers. It presents our view on the most pressing research needs for promoting the integration of chytrid fungi into aquatic ecology.
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- 2017
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14. Exploring the diversity and distribution of freshwater aerobic anoxygenic phototrophs in a latitudinal gradient
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Ferrera, Isabel, Priscu, John C., Chiuchiolo, Amy, Sarmento, Hugo, and Grossart, Hans-Peter
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education ,virus diseases ,humanities ,eye diseases ,health care economics and organizations - Abstract
15th International Symposium on Microbial Ecology (ISME15), 24-29 August 2014, Seoul, South-Korea
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- 2014
15. Contrasting effects of singlet oxygen and hydrogen peroxide on bacterial community composition in a humic lake
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Glaeser, Stefanie P., Berghoff, Bork A., Stratmann, Verena, Grossart, Hans-Peter, Glaeser, Jens, and Justus Liebig University Giessen
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ddc:570 - Abstract
Light excitation of humic matter generates reactive oxygen species (ROS) in surface waters of aquatic ecosystems. Abundant ROS generated in humic matter rich lakes include singlet oxygen (1O2) and hydrogen peroxide (H2O2). Because these ROS differ in half-life time and toxicity, we compared their effects on microbial activity (14C-Leucine incorporation) and bacterial community composition (BCC) in surface waters of humic Lake Grosse Fuchskuhle (North-eastern Germany). For this purpose, experiments with water samples collected from the lake were conducted in July 2006, September 2008 and August 2009. Artificially increased 1O2 and H2O2 concentrations inhibited microbial activity in water samples to a similar extent, but the effect of the respective ROS on BCC varied strongly. BCC analysis by 16S rRNA gene clone libraries and RT-PCR DGGE revealed ROS specific changes in relative abundance and activity of major bacterial groups and composition of dominating phylotypes. These changes were consistent in the three experiments performed in different years. The relative abundance of Polynucleobacter necessarius, Limnohabitans-related phylotypes (Betaproteobacteria), and Novosphingobium acidiphilum (Alphaproteobacteria) increased or was not affected by photo-sensitized 1O2 exposure, but decreased after H2O2 exposure. The opposite pattern was found for Actinobacteria of the freshwater AcI-B cluster which were highly sensitive to 1O2 but not to H2O2 exposure. Furthermore, group-specific RT-PCR DGGE analysis revealed that particle-attached P. necessarius and Limnohabitans-related phylotypes exhibit higher resistance to 1O2 exposure compared to free-living populations. These results imply that 1O2 acts as a factor in niche separation of closely affiliated Polynucleobacter and Limnohabitans-related phylotypes. Consequently, oxidative stress caused by photochemical ROS generation should be regarded as an environmental variable determining abundance, activity, and phylotype composition of environmentally relevant bacterial groups, in particular in illuminated and humic matter rich waters.
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- 2014
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16. Towards an improved understanding of biogeochemical processes across surface-groundwater interactions in intermittent rivers and ephemeral streams
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Gómez-Gener, Lluís, Siebers, Andre, Arce, María Isabel, Arnon, Shai, Bernal, Susana, Bolpagni, Rossano, Datry, Thibault, Gionchetta, Giulia, Grossart, Hans-Peter, Mendoza-Lera, Clara, Pohl, Vivien, Risse-Buhl, Ute, Shumilova, Oleksandra, Tzoraki, Ourania, von Schiller, Daniel, Weigand, Alexander, Weigelhofer, Gabriele, Zak, Dominik, and Zoppini, Annamaria
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13. Climate action ,15. Life on land ,6. Clean water ,Uncategorized - Abstract
Surface-groundwater interactions in intermittent rivers and ephemeral streams (IRES), waterways which do not flow year-round, are spatially and temporally dynamic because of alternations between flowing, non-flowing and dry hydrological states. Interactions between surface and groundwater often create mixing zones with distinct redox gradients, potentially driving high rates of carbon and nutrient cycling. Yet a complete understanding of how underlying biogeochemical processes across surface-groundwater flowpaths in IRES differ among various hydrological states remains elusive. Here, we present a conceptual framework relating spatial and temporal hydrological variability in surface water-groundwater interactions to biogeochemical processing hotspots in IRES.
17. Storm impacts on phytoplankton community dynamics in lakes
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Stockwell, Jason D., Doubek, Jonathan P., Adrian, Rita, Anneville, Orlane, Carey, Cayelan C., Carvalho, Laurence, Senerpont Domis, Lisette N., Dur, Gaël, Frassl, Marieke A., and Grossart, Hans‐Peter
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extreme events ,climate change ,environmental disturbance ,13. Climate action ,nutrients ,mixing ,functional traits ,500 Naturwissenschaften und Mathematik::570 Biowissenschaften ,Biologie::570 Biowissenschaften ,Biologie ,15. Life on land ,stability ,watershed - Abstract
In many regions across the globe, extreme weather events such as storms have increased in frequency, intensity, and duration due to climate change. Ecological theory predicts that such extreme events should have large impacts on ecosystem structure and function. High winds and precipitation associated with storms can affect lakes via short‐term runoff events from watersheds and physical mixing of the water column. In addition, lakes connected to rivers and streams will also experience flushing due to high flow rates. Although we have a well‐developed understanding of how wind and precipitation events can alter lake physical processes and some aspects of biogeochemical cycling, our mechanistic understanding of the emergent responses of phytoplankton communities is poor. Here we provide a comprehensive synthesis that identifies how storms interact with lake and watershed attributes and their antecedent conditions to generate changes in lake physical and chemical environments. Such changes can restructure phytoplankton communities and their dynamics, as well as result in altered ecological function (e.g., carbon, nutrient and energy cycling) in the short‐ and long‐term. We summarize the current understanding of storm‐induced phytoplankton dynamics, identify knowledge gaps with a systematic review of the literature, and suggest future research directions across a gradient of lake types and environmental conditions.
18. Towards an improved understanding of biogeochemical processes across surface-groundwater interactions in intermittent rivers and ephemeral streams
- Author
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Gómez-Gener, Lluís, Siebers, Andre, Arce, María Isabel, Arnon, Shai, Bernal, Susana, Bolpagni, Rossano, Datry, Thibault, Gionchetta, Giulia, Grossart, Hans-Peter, Mendoza-Lera, Clara, Pohl, Vivien, Risse-Buhl, Ute, Shumilova, Oleksandra, Tzoraki, Ourania, von Schiller, Daniel, Weigand, Alexander, Weigelhofer, Gabriele, Zak, Dominik, and Zoppini, Annamaria
- Subjects
13. Climate action ,15. Life on land ,6. Clean water ,Uncategorized - Abstract
Surface-groundwater interactions in intermittent rivers and ephemeral streams (IRES), waterways which do not flow year-round, are spatially and temporally dynamic because of alternations between flowing, non-flowing and dry hydrological states. Interactions between surface and groundwater often create mixing zones with distinct redox gradients, potentially driving high rates of carbon and nutrient cycling. Yet a complete understanding of how underlying biogeochemical processes across surface-groundwater flowpaths in IRES differ among various hydrological states remains elusive. Here, we present a conceptual framework relating spatial and temporal hydrological variability in surface water-groundwater interactions to biogeochemical processing hotspots in IRES.
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