TY - GEN A1 - Kahl, Sandra A1 - Kappel, Christian A1 - Joshi, Jasmin Radha A1 - Lenhard, Michael T1 - Phylogeography of a widely distributed plant species reveals cryptic genetic lineages with parallel phenotypic responses to warming and drought conditions T2 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - To predict how widely distributed species will perform under future climate change, it is crucial to understand and reveal their underlying phylogenetics. However, detailed information about plant adaptation and its genetic basis and history remains scarce and especially widely distributed species receive little attention despite their putatively high adaptability. To examine the adaptation potential of a widely distributed species, we sampled the model plant Silene vulgaris across Europe. In a greenhouse experiment, we exposed the offspring of these populations to a climate change scenario for central Europe and revealed the population structure through whole-genome sequencing. Plants were grown under two temperatures (18°C and 21°C) and three precipitation regimes (65, 75, and 90 mm) to measure their response in biomass and fecundity-related traits. To reveal the population genetic structure, ddRAD sequencing was employed for a whole-genome approach. We found three major genetic clusters in S. vulgaris from Europe: one cluster comprising Southern European populations, one cluster of Western European populations, and another cluster containing central European populations. Population genetic diversity decreased with increasing latitude, and a Mantel test revealed significant correlations between FST and geographic distances as well as between genetic and environmental distances. Our trait analysis showed that the genetic clusters significantly differed in biomass-related traits and in the days to flowering. However, half of the traits showed parallel response patterns to the experimental climate change scenario. Due to the differentiated but parallel response patterns, we assume that phenotypic plasticity plays an important role for the adaptation of the widely distributed species S. vulgaris and its intraspecific genetic lineages. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1218 KW - climate adaptation KW - ddRAD KW - Silene vulgaris Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-530035 SN - 1866-8372 SP - 13986 EP - 14002 ER - TY - GEN A1 - Romero-Mujalli, Daniel A1 - Rochow, Markus A1 - Kahl, Sandra A1 - Paraskevopoulou, Sofia A1 - Folkertsma, Remco A1 - Jeltsch, Florian A1 - Tiedemann, Ralph T1 - Adaptive and nonadaptive plasticity in changing environments: Implications for sexual species with different life history strategies T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Populations adapt to novel environmental conditions by genetic changes or phenotypic plasticity. Plastic responses are generally faster and can buffer fitness losses under variable conditions. Plasticity is typically modeled as random noise and linear reaction norms that assume simple one-to- one genotype–phenotype maps and no limits to the phenotypic response. Most studies on plasticity have focused on its effect on population viability. However, it is not clear, whether the advantage of plasticity depends solely on environmental fluctuations or also on the genetic and demographic properties (life histories) of populations. Here we present an individual-based model and study the relative importance of adaptive and nonadaptive plasticity for populations of sexual species with different life histories experiencing directional stochastic climate change. Environmental fluctuations were simulated using differentially autocorrelated climatic stochasticity or noise color, and scenarios of directiona climate change. Nonadaptive plasticity was simulated as a random environmental effect on trait development, while adaptive plasticity as a linear, saturating, or sinusoidal reaction norm. The last two imposed limits to the plastic response and emphasized flexible interactions of the genotype with the environment. Interestingly, this assumption led to (a) smaller phenotypic than genotypic variance in the population (many-to- one genotype–phenotype map) and the coexistence of polymorphisms, and (b) the maintenance of higher genetic variation—compared to linear reaction norms and genetic determinism—even when the population was exposed to a constant environment for several generations. Limits to plasticity led to genetic accommodation, when costs were negligible, and to the appearance of cryptic variation when limits were exceeded. We found that adaptive plasticity promoted population persistence under red environmental noise and was particularly important for life histories with low fecundity. Populations produing more offspring could cope with environmental fluctuations solely by genetic changes or random plasticity, unless environmental change was too fast. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1170 KW - developmental canalization KW - environmental change KW - genetic accommodation KW - Individual-based models KW - limits KW - many-to-one genotype–phenotype map KW - noise color KW - phenotypic plasticity KW - reaction norms KW - stochastic fluctuations Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-523201 SN - 1866-8372 IS - 1170 ER - TY - JOUR A1 - Zwickel, Theresa A1 - Kahl, Sandra A1 - Klaffke, Horst A1 - Rychlik, Michael A1 - Müller, Marina E. H. T1 - Spotlight on the Underdogs-An Analysis of Underrepresented Alternaria Mycotoxins Formed Depending on Varying Substrate, Time and Temperature Conditions JF - Toxins N2 - Alternaria (A.) is a genus of widespread fungi capable of producing numerous, possibly health-endangering Alternaria toxins (ATs), which are usually not the focus of attention. The formation of ATs depends on the species and complex interactions of various environmental factors and is not fully understood. In this study the influence of temperature (7 degrees C, 25 degrees C), substrate (rice, wheat kernels) and incubation time (4, 7, and 14 days) on the production of thirteen ATs and three sulfoconjugated ATs by three different Alternaria isolates from the species groups A. tenuissima and A. infectoria was determined. High-performance liquid chromatography coupled with tandem mass spectrometry was used for quantification. Under nearly all conditions, tenuazonic acid was the most extensively produced toxin. At 25 degrees C and with increasing incubation time all toxins were formed in high amounts by the two A. tenuissima strains on both substrates with comparable mycotoxin profiles. However, for some of the toxins, stagnation or a decrease in production was observed from day 7 to 14. As opposed to the A. tenuissima strains, the A. infectoria strain only produced low amounts of ATs, but high concentrations of stemphyltoxin III. The results provide an essential insight into the quantitative in vitro AT formation under different environmental conditions, potentially transferable to different field and storage conditions. KW - Alternaria infectoria KW - A. tenuissima KW - mycotoxin profile KW - wheat KW - rice KW - Alternaria toxin sulfates KW - modified Alternaria toxins KW - altertoxins KW - altenuic acid KW - HPLC-MS/MS Y1 - 2016 U6 - https://doi.org/10.3390/toxins8110344 SN - 2072-6651 VL - 8 SP - 570 EP - 583 PB - MDPI CY - Basel ER - TY - THES A1 - Arias Andrés, María de Jesús T1 - Microbial gene exchange on microplastic particles T1 - Mikrobieller Gentransfer auf Mikroplastikpartikel N2 - Plastic pollution is ubiquitous on the planet since several millions of tons of plastic waste enter aquatic ecosystems each year. Furthermore, the amount of plastic produced is expected to increase exponentially shortly. The heterogeneity of materials, additives and physical characteristics of plastics are typical of these emerging contaminants and affect their environmental fate in marine and freshwaters. Consequently, plastics can be found in the water column, sediments or littoral habitats of all aquatic ecosystems. Most of this plastic debris will fragment as a product of physical, chemical and biological forces, producing particles of small size. These particles (< 5mm) are known as “microplastics” (MP). Given their high surface-to-volume ratio, MP stimulate biofouling and the formation of biofilms in aquatic systems. As a result of their unique structure and composition, the microbial communities in MP biofilms are referred to as the “Plastisphere.” While there is increasing data regarding the distinctive composition and structure of the microbial communities that form part of the plastisphere, scarce information exists regarding the activity of microorganisms in MP biofilms. This surface-attached lifestyle is often associated with the increase in horizontal gene transfer (HGT) among bacteria. Therefore, this type of microbial activity represents a relevant function worth to be analyzed in MP biofilms. The horizontal exchange of mobile genetic elements (MGEs) is an essential feature of bacteria. It accounts for the rapid evolution of these prokaryotes and their adaptation to a wide variety of environments. The process of HGT is also crucial for spreading antibiotic resistance and for the evolution of pathogens, as many MGEs are known to contain antibiotic resistance genes (ARGs) and genetic determinants of pathogenicity. In general, the research presented in this Ph.D. thesis focuses on the analysis of HGT and heterotrophic activity in MP biofilms in aquatic ecosystems. The primary objective was to analyze the potential of gene exchange between MP bacterial communities vs. that of the surrounding water, including bacteria from natural aggregates. Moreover, the thesis addressed the potential of MP biofilms for the proliferation of biohazardous bacteria and MGEs from wastewater treatment plants (WWTPs) and associated with antibiotic resistance. Finally, it seeks to prove if the physiological profile of MP biofilms under different limnological conditions is divergent from that of the water communities. Accordingly, the thesis is composed of three independent studies published in peer-reviewed journals. The two laboratory studies were performed using both model and environmental microbial communities. In the field experiment, natural communities from freshwater ecosystems were examined. In Chapter I, the inflow of treated wastewater into a temperate lake was simulated with a concentration gradient of MP particles. The effects of MP on the microbial community structure and the occurrence of integrase 1 (int 1) were followed. The int 1 is a marker associated with mobile genetic elements and known as a proxy for anthropogenic effects on the spread of antimicrobial resistance genes. During the experiment, the abundance of int1 increased in the plastisphere with increasing MP particle concentration, but not in the surrounding water. In addition, the microbial community on MP was more similar to the original wastewater community with increasing microplastic concentrations. Our results show that microplastic particles indeed promote persistence of standard indicators of microbial anthropogenic pollution in natural waters. In Chapter II, the experiments aimed to compare the permissiveness of aquatic bacteria towards model antibiotic resistance plasmid pKJK5, between communities that form biofilms on MP vs. those that are free-living. The frequency of plasmid transfer in bacteria associated with MP was higher when compared to bacteria that are free-living or in natural aggregates. Moreover, comparison increased gene exchange occurred in a broad range of phylogenetically-diverse bacteria. The results indicate a different activity of HGT in MP biofilms, which could affect the ecology of aquatic microbial communities on a global scale and the spread of antibiotic resistance. Finally, in Chapter III, physiological measurements were performed to assess whether microorganisms on MP had a different functional diversity from those in water. General heterotrophic activity such as oxygen consumption was compared in microcosm assays with and without MP, while diversity and richness of heterotrophic activities were calculated by using Biolog® EcoPlates. Three lakes with different nutrient statuses presented differences in MP-associated biomass build up. Functional diversity profiles of MP biofilms in all lakes differed from those of the communities in the surrounding water, but only in the oligo-mesotrophic lake MP biofilms had a higher functional richness compared to the ambient water. The results support that MP surfaces act as new niches for aquatic microorganisms and can affect global carbon dynamics of pelagic environments. Overall, the experimental works presented in Chapters I and II support a scenario where MP pollution affects HGT dynamics among aquatic bacteria. Among the consequences of this alteration is an increase in the mobilization and transfer efficiency of ARGs. Moreover, it supposes that changes in HGT can affect the evolution of bacteria and the processing of organic matter, leading to different catabolic profiles such as demonstrated in Chapter III. The results are discussed in the context of the fate and magnitude of plastic pollution and the importance of HGT for bacterial evolution and the microbial loop, i.e., at the base of aquatic food webs. The thesis supports a relevant role of MP biofilm communities for the changes observed in the aquatic microbiome as a product of intense human intervention. N2 - Die Plastikverschmutzung ist auf dem Planeten allgegenwärtig, da jährlich mehrere Millionen Tonnen Plastikabfall in die aquatische Ökosystemen gelangen. Darüber hinaus wird erwartet, dass die Menge an produziertem Plastik in naher Zukunft exponentiell ansteigen wird. Die Heterogenität der Kunststoffmaterialien, ihrer Additive und physikalischen Eigenschaften ist typisch für diese neu auftretenden Schadstoffe und beeinflusst deren Umweltverhalten in Meeres- und Süßwasser. Als Folge kann Plastik in der Wassersäule, den Sedimenten oder Küstenlebensräumen aller aquatischen Ökosysteme gefunden werden. Die meisten dieser Plastikabfälle fragmentieren durch das Zusammenspiel physikalischer, chemischer und biologischer Kräfte, wodurch kleine Partikel erzeugt werden. Diese Partikel (<5mm) sind auch bekannt als "Mikroplastik" (MP). Aufgrund ihres hohen Oberflächen-Volumen-Verhältnisses stimuliert MP das Biofouling und somit die Bildung von Biofilmen in aquatischen Systemen. Aufgrund ihrer einzigartigen Struktur und Zusammensetzung werden die mikrobiellen Gemeinschaften in MP-Biofilmen als "Plastisphäre" bezeichnet. Während es immer mehr Daten über die spezifische Zusammensetzung und Struktur der mikrobiellen Gemeinschaften – die Teil dieser Plastisphäre sind – gibt, existieren hingegen nur wenige Informationen über die Aktivität von Mikroorganismen in MP-Biofilmen. Dieser Lebensstil des Anheftens und Besiedelns von Oberflächen ist oft mit der Zunahme von horizontalem Gentransfer (HGT) unter Bakterien verknüpft. Diese Art der mikrobiellen Aktivität stellt eine besonders relevante Funktion dar und sollte daher in MP-Biofilmen analysiert werden. Der horizontale Austausch von mobilen genetischen Elementen (MGEs) ist ein wesentliches Merkmal von Bakterien. Er ist verantwortlich für die schnelle Evolution dieser Prokaryoten und ihre Anpassungsfähigkeit an verschiedenste Umweltbedingungen. Der Prozess des HGT ist zudem entscheidend für die Verbreitung von Antibiotikaresistenzen sowie für die Entwicklung von Pathogenen, da viele MGEs bekanntermaßen Antibiotikaresistenzgene (ARGs) und genetische Determinanten für Pathogenität enthalten. Im Allgemeinen konzentriert sich die Forschung in der vorliegenden Dissertation auf die Analyse des HGT und der heterotrophen Aktivität in MP-Biofilmen in aquatischen Ökosystemen. Das Hauptziel besteht darin, das Potenzial des Genaustausches zwischen MP-Bakteriengemeinschaften und dem des umgebenden Wassers, einschließlich der Bakterien in natürlichen Aggregaten, zu analysieren. Darüber hinaus befasst sich diese Doktorarbeit mit dem Potenzial von MP-Biofilmen zur Ausbreitung biologisch gefährlicher Bakterien und MGEs, die aus Kläranlagen stammen und mit Antibiotikaresistenzen assoziiert sind. Schließlich soll bei verschiedenen limnologischen Bedingungen überprüft werden, ob das jeweilige physiologische Profil von MP-Biofilmen von dem der Wassergemeinschaften abweicht. Dementsprechend besteht die Arbeit aus drei unabhängigen Studien, die in Fachzeitschriften veröffentlicht wurden. In den beiden Laborstudien wurden sowohl mikrobielle Modell- als auch Umwelt-Gemeinschaften betrachtet. Im Freilandexperiment wurden schließlich die natürlichen Gemeinschaften aus Süßwasserökosystemen untersucht. In Kapitel I wurde der Zufluss von geklärtem Abwasser mit einem Konzentrationsgradienten von MP-Partikeln in einen See der gemäßigten Klimazone simuliert. Dabei wurden die Effekte von MP auf die mikrobielle Gemeinschaftsstruktur und das Auftreten von Integrase 1 (int 1) verfolgt. Int 1 ist ein Marker, der mit mobilen genetischen Elementen assoziiert ist und zur Abschätzung anthropogener Einflüsse auf die Ausbreitung antimikrobieller Resistenzgene verwendet ist. Während des Experiments erhöhte sich das Vorkommen von Int1 in der Plastisphäre mit zunehmender MP-Partikelkonzentration, jedoch nicht im umgebenden Wasser. Darüber hinaus ähnelte die mikrobielle Gemeinschaft auf MP zunehmend der ursprünglichen Abwassergemeinschaft mit steigender Mikroplastikkonzentration. Unsere Ergebnisse zeigen, dass Mikroplastikpartikel tatsächlich die Persistenz von Standardindikatoren mikrobieller anthropogener Verschmutzung in natürlichen Gewässern fördern. In Kapitel II wurde die Permissivität von aquatischen Bakterien gegen das Modell-Plasmid für Antibiotikaresistenz pKJK5 zwischen Gemeinschaften, die Biofilme auf MP bilden, gegenüber denen, die frei leben, verglichen. Die Häufigkeit des Plasmidtransfers unter den MP-assoziierten Bakterien war höher als unter Bakterien, die frei oder in natürlichen Aggregaten leben. Der verstärkte Genaustausch trat darüber hinaus bei einem breiten Spektrum phylogenetisch diverser Bakterien auf. Die Ergebnisse deuten auf eine unterschiedliche Aktivität von HGT in MP-Biofilmen hin, welche die Ökologie aquatischer mikrobieller Gemeinschaften auf globaler Ebene sowie die Verbreitung von Antibiotikaresistenzen beeinflussen könnten. Schließlich wurden in Kapitel III physiologische Messungen durchgeführt, um festzustellen, ob Mikroorganismen auf MP eine andere funktionelle Diversität aufwiesen als jene im Wasser. Die generelle heterotrophe Aktivität, wie der Sauerstoffverbrauch, wurde in Mikrokosmentests mit und ohne MP verglichen, während die Diversität und Vielfalt heterotropher Aktivitäten mit Hilfe von Biolog® EcoPlates berechnet wurden. Drei Seen mit unterschiedlichen Nährstoffbedingungen wiesen Unterschiede in der Ausprägung der MP-assoziierten Biomasse auf. In allen Seen unterschieden sich die funktionellen Diversitätsprofile der MP-Biofilme von denen der Gemeinschaften im umgebenden Wasser, aber nur die MP-Biofilme des oligo-mesotrophen Sees hatten eine höhere funktionelle Vielfalt im Verglichen zum Umgebungswasser. Die Ergebnisse verdeutlichen, dass MP-Oberflächen als neue Nischen für aquatische Mikroorganismen fungieren und die globale Kohlenstoffdynamik im Pelagial beeinflussen können. Insgesamt unterstützen die in den Kapiteln I und II vorgestellten experimentellen Studien ein Szenario, in dem die Umweltverschmutzung durch MP die HGT-Dynamik zwischen aquatischen Bakterien beeinflusst. Zu den Folgen dieser Veränderung gehört eine Erhöhung der Mobilisierungs- und Übertragungseffizienz von ARGs. Darüber hinaus wird vermutet, dass eine Beeinflussung des HGT die Evolution von Bakterien und die Umsetzung von organischem Material verändern könnte, was zu verschiedenen katabolischen Profilen führt, wie in Kapitel III gezeigt. Die Ergebnisse werden in Zusammenhang mit dem Ausmaß der Plastikverschmutzung sowie der Bedeutung von HGT für die bakterielle Entwicklung und „mikrobielle Schleife“, d. h. an der Basis der aquatischen Nahrungsnetze, diskutiert. Diese Doktorarbeit veranschaulicht die Bedeutung von MP-Biofilmgemeinschaften für die beobachteten Veränderungen des aquatischen Mikrobioms als eine Folge der intensiven anthropogenen Eingriffe. KW - microplastics KW - horizontal gene transfer KW - aquatic ecosystem KW - microorganisms KW - Mikroplastikpartikel KW - horizontaler Gentransfer KW - aquatische Ökosysteme KW - Mikroorganismen Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-417241 ER - TY - THES A1 - Liu, Qi T1 - Influence of CO2 degassing on microbial community distribution and activity in the Hartoušov degassing system, western Eger Rift (Czech Republic) N2 - The Cheb Basin (CZ) is a shallow Neogene intracontinental basin located in the western Eger Rift. The Cheb Basin is characterized by active seismicity and diffuse degassing of mantle-derived CO2 in mofette fields. Within the Cheb Basin, the Hartoušov mofette field shows a daily CO2 flux of 23–97 tons. More than 99% of CO2 released over an area of 0.35 km2. Seismic active periods have been observed in 2000 and 2014 in the Hartoušov mofette field. Due to the active geodynamic processes, the Cheb Basin is considered to be an ideal region for the continental deep biosphere research focussing on the interaction of biological processes with geological processes. To study the influence of CO2 degassing on microbial community in the surface and subsurface environments, two 3-m shallow drillings and a 108.5-m deep scientific drilling were conducted in 2015 and 2016 respectively. Additionally, the fluid retrieved from the deep drilling borehole was also recovered. The different ecosystems were compared regarding their geochemical properties, microbial abundances, and microbial community structures. The geochemistry of the mofette is characterized by low pH, high TOC, and sulfate contents while the subsurface environment shows a neutral pH, and various TOC and sulfate contents in different lithological settings. Striking differences in the microbial community highlight the substantial impact of elevated CO2 concentrations and high saline groundwater on microbial processes. In general, the microorganisms had low abundance in the deep subsurface sediment compared with the shallow mofette. However, within the mofette and the deep subsurface sediment, the abundance of microbes does not show a typical decrease with depth, indicating that the uprising CO2-rich groundwater has a strong influence on the microbial communities via providing sufficient substrate for anaerobic chemolithoautotrophic microorganisms. Illumina MiSeq sequencing of the 16S rRNA genes and multivariate statistics reveals that the pH strongly influences the microbial community composition in the mofette, while the subsurface microbial community is significantly influenced by the groundwater which motivated by the degassing CO2. Acidophilic microorganisms show a much higher relative abundance in the mofette. Meanwhile, the OTUs assigned to family Comamonadaceae are the dominant taxa which characterize the subsurface communities. Additionally, taxa involved in sulfur cycling characterizing the microbial communities in both mofette and CO2 dominated subsurface environments. Another investigated important geo–bio interaction is the influence of the seismic activity. During seismic events, released H2 may serve as the electron donor for microbial hydrogenotrophic processes, such as methanogenesis. To determine whether the seismic events can potentially trigger methanogenesis by the elevated geogenic H2 concentration, we performed laboratory simulation experiments with sediments retrieved from the drillings. The simulation results indicate that after the addition of hydrogen, substantial amounts of methane were produced in incubated mofette sediments and deep subsurface sediments. The methanogenic hydrogenotrophic genera Methanobacterium was highly enriched during the incubation. The modeling of the in-situ observation of the earthquake swarm period in 2000 at the Novy Kostel focal area/Czech Republic and our laboratory simulation experiments reveals a close relation between seismic activities and microbial methane production via earthquake-induced H2 release. We thus conclude that H2 – which is released during seismic activity – can potentially trigger methanogenic activity in the deep subsurface. Based on this conclusion, we further hypothesize that the hydrogenotrophic early life on Earth was boosted by the Late Heavy Bombardment induced seismic activity in approximately 4.2 to 3.8 Ga. N2 - Das Eger-Becken (CZ) ist ein flaches, intrakontinentales neogenes Becken im westlichen Eger-Graben. Das Eger-Becken zeichnet sich durch aktive Seismizität und die diffuse Entgasung von aus dem Mantel stammenden CO2 in Mofettenfeldern aus. Das Mofettenfeld von Hartoušov weist einen täglichen CO2-Fluss von 23-97 Tonnen auf. Mehr als 99% des CO2 werden auf einer Fläche von 0,35 km2 freigesetzt. Im Untersuchungsgebiet wurden in den Jahren 2000 und 2014 seismisch aktive Perioden beobachtet. Aufgrund der aktiven geodynamischen Prozesse gilt das Egerer Becken als ideale Region für die kontinentale Tiefenbiosphärenforschung, die sich auf die Wechselwirkung von biologischen Prozessen mit geologischen Prozessen konzentriert. Zur Untersuchung des Einflusses der CO2-Entgasung auf die mikrobielle Gemeinschaft in der ober- und unterirdischen Umwelt wurden 2015 und 2016 zwei 3 m tiefe Flachbohrungen und eine 108,5 m tiefe wissenschaftliche Bohrung durchgeführt. Zusätzlich wurde auch aus dem Tiefbohrloch Flüssigkeit gewonnen. Die verschiedenen Ökosysteme wurden hinsichtlich ihrer geochemischen Eigenschaften, der mikrobiellen Abundanzen und der mikrobiellen Gemeinschaftsstrukturen verglichen. Die Geochemie der Mofetten zeichnet sich durch einen niedrigen pH-Wert und hohe TOC- und Sulfatgehalte aus, während das unterirdische Milieu einen neutralen pH-Wert und verschiedene TOC- und Sulfatgehalte in unterschiedlichen lithologischen Umgebungen aufweist. Auffällige Unterschiede in der mikrobiellen Gemeinschaft unterstreichen den erheblichen Einfluss erhöhter CO2-Konzentrationen und stark salzhaltigen Grundwassers auf mikrobielle Prozesse. Generell waren die mikrobiellen Abundanzen in dem tiefen Untergrundsediment im Vergleich zur flachen Mofette gering. Innerhalb der Mofette und des tiefen unterirdischen Sediments zeigt die Häufigkeit der Mikroorganismen jedoch keine typische Abnahme mit der Tiefe, was darauf hinweist, dass das aufsteigende CO2-reiche Grundwasser einen starken Einfluss auf die mikrobiellen Gemeinschaften hat, indem es genügend Substrat für anaerobe chemolithoautotrophe Mikroorganismen bietet. Die Illumina-MiSeq-Sequenzierung der 16S rRNA-Gene und die multivariate Statistik zeigen, dass der pH-Wert die Zusammensetzung der mikrobiellen Gemeinschaft in der Mofette signifikant bestimmt, während die unterirdische mikrobielle Gemeinschaft signifikant vom Grundwasser beeinflusst wird, das durch das ausgasende CO2 geprägt ist. Azidophile Mikroorganismen zeigen eine viel höhere relative Abundanz in der Mofette, wohingegen die der Familie Comamonadaceae zugeordneten OTUs die dominierenden Taxa der unterirdischen Gemeinschaften darstellen. Zusätzlich charakterisieren Taxa, die am Schwefelzyklus beteiligt sind, die mikrobiellen Gemeinschaften sowohl in der Mofette als auch in der CO2-dominierten unterirdischen Umwelt. Eine weitere wichtige Untersuchung der Geo-Bio-Interaktion ist der Einfluss der seismischen Aktivität. Während seismischer Ereignisse kann freigesetztes H2 als Elektronendonator für mikrobielle hydrogenotrophe Prozesse, wie z.B. die Methanogenese, dienen. Um zu bestimmen, ob die seismischen Ereignisse durch die erhöhten geogenen H2-Konzentrationen möglicherweise methanogene Prozesse auslösen können, führten wir Laborsimulationsexperimente mit Sedimenten durch, die aus den Bohrungen gewonnen wurden. Die Simulationsexperimente weisen darauf hin, dass nach der Zugabe von Wasserstoff beträchtliche Mengen an Methan in inkubierten Mofettensedimenten und tiefen unterirdischen Sedimenten produziert wurden. Die methanogene hydrogenotrophe Gattung Methanobacterium wurde während der Inkubation stark angereichert. Die Modellierung der in-situ-Beobachtung der Erdbeben-Schwarmzeit im Jahr 2000 im Schwerpunktgebiet Novy Kostel/Tschechische Republik und unsere Laborsimulationsexperimente zeigen einen engen Zusammenhang zwischen seismischen Aktivitäten und der biotischen Methanproduktion durch erdbebeninduzierte H2-Freisetzung. Wir kommen daher zu dem Schluss, dass H2 - dass bei seismischer Aktivität freigesetzt wird - möglicherweise methanogene Aktivität im tiefen Untergrund auslösen kann. Basierend auf dieser Schlussfolgerung gehen wir weiter davon aus, dass das frühe hydrogenotrophe Leben, durch die durch Late Heavy Bombardment induzierte seismische Aktivität in etwa 4,2 bis 3,8 Ga verstärkt wurde. T2 - Einfluss der CO2-Entgasung auf die Verteilung und Aktivität der mikrobiellen Gemeinschaft im Hartoušov-Entgasungssystem im westlichen Eger-Graben (Tschechische Republik) KW - CO2 degassing KW - western Eger Rift KW - microbial community KW - microbial activity KW - earthquake KW - seismic activity KW - deep biosphere KW - CO2-Entgasung KW - tiefe Biosphäre KW - Erdbeben KW - mikrobielle Aktivität KW - mikrobielle Gemeinschaft KW - seismische Aktivität KW - westlichen Eger-Graben Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-475341 ER - TY - GEN A1 - Wurzbacher, Christian A1 - Fuchs, Andrea A1 - Attermeyer, Katrin A1 - Frindte, Katharina A1 - Grossart, Hans-Peter A1 - Hupfer, Michael A1 - Casper, Peter A1 - Monaghan, Michael T. T1 - Shifts among Eukaryota, Bacteria, and Archaea define the vertical organization of a lake sediment T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Background Lake sediments harbor diverse microbial communities that cycle carbon and nutrients while being constantly colonized and potentially buried by organic matter sinking from the water column. The interaction of activity and burial remained largely unexplored in aquatic sediments. We aimed to relate taxonomic composition to sediment biogeochemical parameters, test whether community turnover with depth resulted from taxonomic replacement or from richness effects, and to provide a basic model for the vertical community structure in sediments. Methods We analyzed four replicate sediment cores taken from 30-m depth in oligo-mesotrophic Lake Stechlin in northern Germany. Each 30-cm core spanned ca. 170 years of sediment accumulation according to 137Cs dating and was sectioned into layers 1–4 cm thick. We examined a full suite of biogeochemical parameters and used DNA metabarcoding to examine community composition of microbial Archaea, Bacteria, and Eukaryota. Results Community β-diversity indicated nearly complete turnover within the uppermost 30 cm. We observed a pronounced shift from Eukaryota- and Bacteria-dominated upper layers (<5 cm) to Bacteria-dominated intermediate layers (5–14 cm) and to deep layers (>14 cm) dominated by enigmatic Archaea that typically occur in deep-sea sediments. Taxonomic replacement was the prevalent mechanism in structuring the community composition and was linked to parameters indicative of microbial activity (e.g., CO2 and CH4 concentration, bacterial protein production). Richness loss played a lesser role but was linked to conservative parameters (e.g., C, N, P) indicative of past conditions. Conclusions By including all three domains, we were able to directly link the exponential decay of eukaryotes with the active sediment microbial community. The dominance of Archaea in deeper layers confirms earlier findings from marine systems and establishes freshwater sediments as a potential low-energy environment, similar to deep sea sediments. We propose a general model of sediment structure and function based on microbial characteristics and burial processes. An upper “replacement horizon” is dominated by rapid taxonomic turnover with depth, high microbial activity, and biotic interactions. A lower “depauperate horizon” is characterized by low taxonomic richness, more stable “low-energy” conditions, and a dominance of enigmatic Archaea. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1111 KW - Archaea KW - Eukaryota KW - Bacteria KW - community KW - freshwater KW - lake KW - DNA metabarcoding KW - beta-diversity KW - sediment KW - turnover Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-431965 SN - 1866-8372 IS - 1111 ER - TY - GEN A1 - Gubelit, Yulia I. A1 - Grossart, Hans-Peter T1 - New Methods, New Concepts BT - What Can Be Applied to Freshwater Periphyton? T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Microbial interactions play an essential role in aquatic ecosystems and are of the great interest for both marine and freshwater ecologists. Recent development of new technologies and methods allowed to reveal many functional mechanisms and create new concepts. Yet, many fundamental aspects of microbial interactions have been almost exclusively studied for marine pelagic and benthic ecosystems. These studies resulted in a formulation of the Black Queen Hypothesis, a development of the phycosphere concept for pelagic communities, and a realization of microbial communication as a key mechanism for microbial interactions. In freshwater ecosystems, especially for periphyton communities, studies focus mainly on physiology, biodiversity, biological indication, and assessment, but the many aspects of microbial interactions are neglected to a large extent. Since periphyton plays a great role for aquatic nutrient cycling, provides the basis for water purification, and can be regarded as a hotspot of microbial biodiversity, we highlight that more in-depth studies on microbial interactions in periphyton are needed to improve our understanding on functioning of freshwater ecosystems. In this paper we first present an overview on recent concepts (e.g., the “Black Queen Hypothesis”) derived from state-of-the-art OMICS methods including metagenomics, metatranscriptomics, and metabolomics. We then point to the avenues how these methods can be applied for future studies on biodiversity and the ecological role of freshwater periphyton, a yet largely neglected component of many freshwater ecosystems. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 969 KW - freshwater KW - lake periphyton KW - microbial interactions KW - Black Queen Hypothesis KW - OMICs tools Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-474286 SN - 1866-8372 IS - 969 ER - TY - GEN A1 - Kettner, Marie Therese A1 - Oberbeckmann, Sonja A1 - Labrenz, Matthias A1 - Grossart, Hans-Peter T1 - The Eukaryotic Life on Microplastics in Brackish Ecosystems T2 - Postprints der Universität Potsdam Mathematisch-Naturwissenschaftliche Reihe N2 - Microplastics (MP) constitute a widespread contaminant all over the globe. Rivers and wastewater treatment plants (WWTP) transport annually several million tons of MP into freshwaters, estuaries and oceans, where they provide increasing artificial surfaces for microbial colonization. As knowledge on MP-attached communities is insufficient for brackish ecosystems, we conducted exposure experiments in the coastal Baltic Sea, an in-flowing river and a WWTP within the drainage basin. While reporting on prokaryotic and fungal communities from the same set-up previously, we focus here on the entire eukaryotic communities. Using high-throughput 18S rRNA gene sequencing, we analyzed the eukaryotes colonizing on two types of MP, polyethylene and polystyrene, and compared them to the ones in the surrounding water and on a natural surface (wood). More than 500 different taxa across almost all kingdoms of the eukaryotic tree of life were identified on MP, dominated by Alveolata, Metazoa, and Chloroplastida. The eukaryotic community composition on MP was significantly distinct from wood and the surrounding water, with overall lower diversity and the potentially harmful dinoflagellate Pfiesteria being enriched on MP. Co-occurrence networks, which include prokaryotic and eukaryotic taxa, hint at possibilities for dynamic microbial interactions on MP. This first report on total eukaryotic communities on MP in brackish environments highlights the complexity of MP-associated biofilms, potentially leading to altered microbial activities and hence changes in ecosystem functions. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 741 KW - microeukaryotes KW - plastic-associated biofilms KW - Baltic Sea KW - polyethylene KW - polystyrene KW - diversity profiles KW - network analysis KW - next-generation sequencing Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-434996 SN - 1866-8372 IS - 741 ER - TY - GEN A1 - Rojas-Jimenez, Keilor A1 - Rieck, Angelika A1 - Wurzbacher, Christian A1 - Jürgens, Klaus A1 - Labrenz, Matthias A1 - Grossart, Hans-Peter T1 - A Salinity Threshold Separating Fungal Communities in the Baltic Sea T2 - Postprints der Universität Potsdam Mathematisch-Naturwissenschaftliche Reihe N2 - Salinity is a significant factor for structuring microbial communities, but little is known for aquatic fungi, particularly in the pelagic zone of brackish ecosystems. In this study, we explored the diversity and composition of fungal communities following a progressive salinity decline (from 34 to 3 PSU) along three transects of ca. 2000 km in the Baltic Sea, the world’s largest estuary. Based on 18S rRNA gene sequence analysis, we detected clear changes in fungal community composition along the salinity gradient and found significant differences in composition of fungal communities established above and below a critical value of 8 PSU. At salinities below this threshold, fungal communities resembled those from freshwater environments, with a greater abundance of Chytridiomycota, particularly of the orders Rhizophydiales, Lobulomycetales, and Gromochytriales. At salinities above 8 PSU, communities were more similar to those from marine environments and, depending on the season, were dominated by a strain of the LKM11 group (Cryptomycota) or by members of Ascomycota and Basidiomycota. Our results highlight salinity as an important environmental driver also for pelagic fungi, and thus should be taken into account to better understand fungal diversity and ecological function in the aquatic realm. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 739 KW - fungal diversity KW - baltic sea KW - salinity gradient KW - brackish waters KW - chytridiomycota KW - cryptomycota Y1 - 1019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-434937 SN - 1866-8372 IS - 739 ER - TY - THES A1 - Périllon, Cécile T1 - The effect of groundwater on benthic primary producers and their interaction T1 - Der Einfluss von Grundwasser auf benthische Primärproduzenten und ihre Interaktionen N2 - In littoral zones of lakes, multiple processes determine lake ecology and water quality. Lacustrine groundwater discharge (LGD), most frequently taking place in littoral zones, can transport or mobilize nutrients from the sediments and thus contribute significantly to lake eutrophication. Furthermore, lake littoral zones are the habitat of benthic primary producers, namely submerged macrophytes and periphyton, which play a key role in lake food webs and influence lake water quality. Groundwater-mediated nutrient-influx can potentially affect the asymmetric competition between submerged macrophytes and periphyton for light and nutrients. While rooted macrophytes have superior access to sediment nutrients, periphyton can negatively affect macrophytes by shading. LGD may thus facilitate periphyton production at the expense of macrophyte production, although studies on this hypothesized effect are missing. The research presented in this thesis is aimed at determining how LGD influences periphyton, macrophytes, and the interactions between these benthic producers. Laboratory experiments were combined with field experiments and measurements in an oligo-mesotrophic hard water lake. In the first study, a general concept was developed based on a literature review of the existing knowledge regarding the potential effects of LGD on nutrients and inorganic and organic carbon loads to lakes, and the effect of these loads on periphyton and macrophytes. The second study includes a field survey and experiment examining the effects of LGD on periphyton in an oligotrophic, stratified hard water lake (Lake Stechlin). This study shows that LGD, by mobilizing phosphorus from the sediments, significantly promotes epiphyton growth, especially at the end of the summer season when epilimnetic phosphorus concentrations are low. The third study focuses on the potential effects of LGD on submerged macrophytes in Lake Stechlin. This study revealed that LGD may have contributed to an observed change in macrophyte community composition and abundance in the shallow littoral areas of the lake. Finally, a laboratory experiment was conducted which mimicked the conditions of a seepage lake. Groundwater circulation was shown to mobilize nutrients from the sediments, which significantly promoted periphyton growth. Macrophyte growth was negatively affected at high periphyton biomasses, confirming the initial hypothesis. More generally, this thesis shows that groundwater flowing into nutrient-limited lakes may import or mobilize nutrients. These nutrients first promote periphyton, and subsequently provoke radical changes in macrophyte populations before finally having a possible influence on the lake’s trophic state. Hence, the eutrophying effect of groundwater is delayed and, at moderate nutrient loading rates, partly dampened by benthic primary producers. The present research emphasizes the importance and complexity of littoral processes, and the need to further investigate and monitor the benthic environment. As present and future global changes can significantly affect LGD, the understanding of these complex interactions is required for the sustainable management of lake water quality. N2 - Im Uferbereich von Seen bestimmen eine Vielzahl von Prozessen das ökologische Gefüge und die Wasserqualität. Grundwasserzustrom, welcher häufig im Uferbereich eines Sees auftritt, kann zum Import von Nährstoffen führen und so signifikant zur Eutrophierung eines Gewässers beitragen. Darüber hinaus bildet der Uferbereich von Seen das Habitat für benthische Primärproduzenten wie Makrophyten (Wasserpflanzen) und Periphyton (Aufwuchs), welche eine Schlüsselrolle im Nahrungsnetz von Seen einnehmen und deren Wasserqualität beeinflussen können. Der durch Grundwasser gesteuerte Eintrag von Nährstoffen kann sich unterschiedlich auf die um Licht und Nährstoffe konkurrierenden Makrophyten und Periphyton auswirken. Während Makrophyten häufig über Wurzeln verfügen und damit Nährstoffe aus dem Sediment aufnehmen, kann Periphyton zu einer Beschattung der Makrophyten beitragen. Grundwasserzustrom könnte deshalb durch Nährstoffzufuhr das Wachstum von Periphyton fördern und damit zu einer Abnahme der Makrophytenabundanz führen. Die in dieser Doktorarbeit vorgestellten Forschungsergebnisse zeigen den Einfluss von einströmendem Grundwasser in Seen auf Makrophyten und Periphyton, und insbesondere die Interaktionen zwischen diesen beiden benthischen Primärproduzenten. Dafür wurden Laborexperimente, sowie Feldexperimente und Messungen in einem oligo-mesotrophen, kalkreichen See miteinander kombiniert. In der ersten Studie wurden im Rahmen einer Literaturrecherche die Auswirkungen des Einstroms von Grundwasser auf das Wachstum von Makrophyten und Periphyton untersucht. Dafür wurden Einträge von Nährstoffen sowie anorganischem und organischem Kohlenstoff berücksichtigt und abschließend ein Konzept entwickelt, das die Interaktion zwischen benthischen Primärproduzenten betrachtet. Die zweite Studie zeigt den Einfluss von Grundwasser auf das Wachstum von Periphyton im geschichteten, oligo-mesotrophen, kalkreichen Stechlinsee (Brandenburg) auf der Basis von Freilanduntersuchungen und -experimenten. Es konnte nachgewiesen werden, dass einströmendes Grundwasser Phosphor aus dem Sediment mobilisiert und so das Wachstum von Periphyton signifikant fördert. Dies war insbesondere am Ende des Sommers relevant, wenn Phosphor im Epilimnion nur noch in sehr geringer Konzentration vorlag. Der Fokus der dritten Studie liegt auf den potenziellen Auswirkungen des Einstroms von Grundwasser auf die Makrophyten in flachen Litoralbereichen des Stechlinsees. Die in den letzten Jahrzehnten beobachteten Veränderungen in der Abundanz und Artenzusammensetzung der Makrophyten, insbesondere der Rückgang der Armleuchteralgen, könnten auch auf Veränderungen im Einstrom von Grundwasser zurückzuführen sein. In der letzten Studie wurden in einem Laborexperiment der Grundwasserzustrom ins Litoral simuliert, um die kombinierte Auswirkung auf Makrophyten- und Periphytonentwicklung unter kontrollierten Umweltbedingungen zu testen. Die Ergebnisse bestätigen die Hypothese, dass die durch den Grundwasserzustrom mobilisierten Nährstoffe aus dem Sediment das Wachstum von Periphyton fördern. Oberhalb eines Grenzwertes der Periphytonbiomasse wird die Entwicklung von Makrophyten behindert. Die vorliegende Arbeit zeigt, dass einströmendes Grundwasser zur Mobilisierung und zum Import von Nährstoffen in Seen führen kann und damit weitreichende Konsequenzen für das ökologische Gefüge und die Wasserqualität haben kann. Die grundwassergesteuerte Nährstoffzufuhr fördert das Wachstum von Periphyton und führt bei genügend großer Periphytonbiomasse zu Änderungen der Makrophytenpopulation bis hin zum Verlust. Die Arbeit verdeutlicht die Relevanz und Komplexität von Prozessen im Litoral von Seen und zeigt zugleich die Notwendigkeit auf, diese benthische Habitate tiefgreifender zu untersuchen. Da globale Veränderungen des Klimas einen weitreichenden Einfluss auf den Grundwassereinstrom in Seen haben können, ist es von entscheidender Bedeutung, die komplexen Auswirkungen dieser Prozesse zu verstehen, um einen nachhaltigen Schutz dieser Ökosysteme zu gewährleisten. KW - groundwater KW - littoral eutrophication KW - benthic primary producers KW - asymmetric competition KW - macrophytes KW - periphyton KW - Grundwasser KW - Makrophyten KW - Periphyton KW - Eutrophierung KW - Litoral KW - benthische Primärproduzenten KW - asymmetrische Konkurrenz Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-406883 ER - TY - GEN A1 - Mantzouki, Evanthia A1 - Lürling, Miquel A1 - Fastner, Jutta A1 - Domis, Lisette Nicole de Senerpont A1 - Wilk-Woźniak, Elżbieta A1 - Koreiviene, Judita A1 - Seelen, Laura A1 - Teurlincx, Sven A1 - Verstijnen, Yvon A1 - Krztoń, Wojciech A1 - Walusiak, Edward A1 - Karosienė, Jūratė A1 - Kasperovičienė, Jūratė A1 - Savadova, Ksenija A1 - Vitonytė, Irma A1 - Cillero-Castro, Carmen A1 - Budzyńska, Agnieszka A1 - Goldyn, Ryszard A1 - Kozak, Anna A1 - Rosińska, Joanna A1 - Szeląg-Wasielewska, Elżbieta A1 - Domek, Piotr A1 - Jakubowska-Krepska, Natalia A1 - Kwasizur, Kinga A1 - Messyasz, Beata A1 - Pełechata, Aleksandra A1 - Pełechaty, Mariusz A1 - Kokocinski, Mikolaj A1 - García-Murcia, Ana A1 - Real, Monserrat A1 - Romans, Elvira A1 - Noguero-Ribes, Jordi A1 - Duque, David Parreño A1 - Fernández-Morán, Elísabeth A1 - Karakaya, Nusret A1 - Häggqvist, Kerstin A1 - Beklioğlu, Meryem A1 - Filiz, Nur A1 - Levi, Eti E. A1 - Iskin, Uğur A1 - Bezirci, Gizem A1 - Tavşanoğlu, Ülkü Nihan A1 - Özhan, Koray A1 - Gkelis, Spyros A1 - Panou, Manthos A1 - Fakioglu, Özden A1 - Avagianos, Christos A1 - Kaloudis, Triantafyllos A1 - Çelik, Kemal A1 - Yilmaz, Mete A1 - Marcé, Rafael A1 - Catalán, Nuria A1 - Bravo, Andrea G. A1 - Buck, Moritz A1 - Colom-Montero, William A1 - Mustonen, Kristiina A1 - Pierson, Don A1 - Yang, Yang A1 - Raposeiro, Pedro M. A1 - Gonçalves, Vítor A1 - Antoniou, Maria G. A1 - Tsiarta, Nikoletta A1 - McCarthy, Valerie A1 - Perello, Victor C. A1 - Feldmann, Tõnu A1 - Laas, Alo A1 - Panksep, Kristel A1 - Tuvikene, Lea A1 - Gagala, Ilona A1 - Mankiewicz-Boczek, Joana A1 - Yağcı, Meral Apaydın A1 - Çınar, Şakir A1 - Çapkın, Kadir A1 - Yağcı, Abdulkadir A1 - Cesur, Mehmet A1 - Bilgin, Fuat A1 - Bulut, Cafer A1 - Uysal, Rahmi A1 - Obertegger, Ulrike A1 - Boscaini, Adriano A1 - Flaim, Giovanna A1 - Salmaso, Nico A1 - Cerasino, Leonardo A1 - Richardson, Jessica A1 - Visser, Petra M. A1 - Verspagen, Jolanda M. H. A1 - Karan, Tünay A1 - Soylu, Elif Neyran A1 - Maraşlıoğlu, Faruk A1 - Napiórkowska-Krzebietke, Agnieszka A1 - Ochocka, Agnieszka A1 - Pasztaleniec, Agnieszka A1 - Antão-Geraldes, Ana M. A1 - Vasconcelos, Vitor A1 - Morais, João A1 - Vale, Micaela A1 - Köker, Latife A1 - Akçaalan, Reyhan A1 - Albay, Meriç A1 - Maronić, Dubravka Špoljarić A1 - Stević, Filip A1 - Pfeiffer, Tanja Žuna A1 - Fonvielle, Jeremy Andre A1 - Straile, Dietmar A1 - Rothhaupt, Karl-Otto A1 - Hansson, Lars-Anders A1 - Urrutia-Cordero, Pablo A1 - Bláha, Luděk A1 - Geriš, Rodan A1 - Fránková, Markéta A1 - Koçer, Mehmet Ali Turan A1 - Alp, Mehmet Tahir A1 - Remec-Rekar, Spela A1 - Elersek, Tina A1 - Triantis, Theodoros A1 - Zervou, Sevasti-Kiriaki A1 - Hiskia, Anastasia A1 - Haande, Sigrid A1 - Skjelbred, Birger A1 - Madrecka, Beata A1 - Nemova, Hana A1 - Drastichova, Iveta A1 - Chomova, Lucia A1 - Edwards, Christine A1 - Sevindik, Tuğba Ongun A1 - Tunca, Hatice A1 - Önem, Burçin A1 - Aleksovski, Boris A1 - Krstić, Svetislav A1 - Vucelić, Itana Bokan A1 - Nawrocka, Lidia A1 - Salmi, Pauliina A1 - Machado-Vieira, Danielle A1 - Oliveira, Alinne Gurjão De A1 - Delgado-Martín, Jordi A1 - García, David A1 - Cereijo, Jose Luís A1 - Gomà, Joan A1 - Trapote, Mari Carmen A1 - Vegas-Vilarrúbia, Teresa A1 - Obrador, Biel A1 - Grabowska, Magdalena A1 - Karpowicz, Maciej A1 - Chmura, Damian A1 - Úbeda, Bárbara A1 - Gálvez, José Ángel A1 - Özen, Arda A1 - Christoffersen, Kirsten Seestern A1 - Warming, Trine Perlt A1 - Kobos, Justyna A1 - Mazur-Marzec, Hanna A1 - Pérez-Martínez, Carmen A1 - Ramos-Rodríguez, Eloísa A1 - Arvola, Lauri A1 - Alcaraz-Párraga, Pablo A1 - Toporowska, Magdalena A1 - Pawlik-Skowronska, Barbara A1 - Niedźwiecki, Michał A1 - Pęczuła, Wojciech A1 - Leira, Manel A1 - Hernández, Armand A1 - Moreno-Ostos, Enrique A1 - Blanco, José María A1 - Rodríguez, Valeriano A1 - Montes-Pérez, Jorge Juan A1 - Palomino, Roberto L. A1 - Rodríguez-Pérez, Estela A1 - Carballeira, Rafael A1 - Camacho, Antonio A1 - Picazo, Antonio A1 - Rochera, Carlos A1 - Santamans, Anna C. A1 - Ferriol, Carmen A1 - Romo, Susana A1 - Soria, Juan Miguel A1 - Dunalska, Julita A1 - Sieńska, Justyna A1 - Szymański, Daniel A1 - Kruk, Marek A1 - Kostrzewska-Szlakowska, Iwona A1 - Jasser, Iwona A1 - Žutinić, Petar A1 - Udovič, Marija Gligora A1 - Plenković-Moraj, Anđelka A1 - Frąk, Magdalena A1 - Bańkowska-Sobczak, Agnieszka A1 - Wasilewicz, Michał A1 - Özkan, Korhan A1 - Maliaka, Valentini A1 - Kangro, Kersti A1 - Grossart, Hans-Peter A1 - Paerl, Hans W. A1 - Carey, Cayelan C. A1 - Ibelings, Bas W. T1 - Temperature effects explain continental scale distribution of cyanobacterial toxins T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Insight into how environmental change determines the production and distribution of cyanobacterial toxins is necessary for risk assessment. Management guidelines currently focus on hepatotoxins (microcystins). Increasing attention is given to other classes, such as neurotoxins (e.g., anatoxin-a) and cytotoxins (e.g., cylindrospermopsin) due to their potency. Most studies examine the relationship between individual toxin variants and environmental factors, such as nutrients, temperature and light. In summer 2015, we collected samples across Europe to investigate the effect of nutrient and temperature gradients on the variability of toxin production at a continental scale. Direct and indirect effects of temperature were the main drivers of the spatial distribution in the toxins produced by the cyanobacterial community, the toxin concentrations and toxin quota. Generalized linear models showed that a Toxin Diversity Index (TDI) increased with latitude, while it decreased with water stability. Increases in TDI were explained through a significant increase in toxin variants such as MC-YR, anatoxin and cylindrospermopsin, accompanied by a decreasing presence of MC-LR. While global warming continues, the direct and indirect effects of increased lake temperatures will drive changes in the distribution of cyanobacterial toxins in Europe, potentially promoting selection of a few highly toxic species or strains. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1105 KW - microcystin KW - anatoxin KW - cylindrospermopsin KW - temperature KW - direct effects KW - indirect effects KW - spatial distribution KW - European Multi Lake Survey Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-427902 SN - 1866-8372 IS - 1105 ER - TY - JOUR A1 - Bjorneras, C. A1 - Weyhenmeyer, G. A. A1 - Evans, C. D. A1 - Gessner, M. O. A1 - Grossart, Hans-Peter A1 - Kangur, K. A1 - Kokorite, I. A1 - Kortelainen, P. A1 - Laudon, H. A1 - Lehtoranta, J. A1 - Lottig, N. A1 - Monteith, D. T. A1 - Noges, P. A1 - Noges, T. A1 - Oulehle, F. A1 - Riise, G. A1 - Rusak, J. A. A1 - Raike, A. A1 - Sire, J. A1 - Sterling, S. A1 - Kritzberg, E. S. T1 - Widespread Increases in Iron Concentration in European and North American Freshwaters JF - Global biogeochemical cycles N2 - Recent reports of increasing iron (Fe) concentrations in freshwaters are of concern, given the fundamental role of Fe in biogeochemical processes. Still, little is known about the frequency and geographical distribution of Fe trends or about the underlying drivers. We analyzed temporal trends of Fe concentrations across 340 water bodies distributed over 10 countries in northern Europe and North America in order to gain a clearer understanding of where, to what extent, and why Fe concentrations are on the rise. We found that Fe concentrations have significantly increased in 28% of sites, and decreased in 4%, with most positive trends located in northern Europe. Regions with rising Fe concentrations tend to coincide with those with organic carbon (OC) increases. Fe and OC increases may not be directly mechanistically linked, but may nevertheless be responding to common regional-scale drivers such as declining sulfur deposition or hydrological changes. A role of hydrological factors was supported by covarying trends in Fe and dissolved silica, as these elements tend to stem from similar soil depths. A positive relationship between Fe increases and conifer cover suggests that changing land use and expanded forestry could have contributed to enhanced Fe export, although increases were also observed in nonforested areas. We conclude that the phenomenon of increasing Fe concentrations is widespread, especially in northern Europe, with potentially significant implications for wider ecosystem biogeochemistry, and for the current browning of freshwaters. Y1 - 2017 U6 - https://doi.org/10.1002/2017GB005749 SN - 0886-6236 SN - 1944-9224 VL - 31 SP - 1488 EP - 1500 PB - American Geophysical Union CY - Washington ER - TY - JOUR A1 - Lischke, Betty A1 - Mehner, Thomas A1 - Hilt, Sabine A1 - Attermeyer, Katrin A1 - Brauns, Mario A1 - Brothers, Soren M. A1 - Grossart, Hans-Peter A1 - Koehler, Jan A1 - Scharnweber, Inga Kristin A1 - Gaedke, Ursula T1 - Benthic carbon is inefficiently transferred in the food webs of two eutrophic shallow lakes JF - Freshwater biology N2 - The sum of benthic autotrophic and bacterial production often exceeds the sum of pelagic autotrophic and bacterial production, and hence may contribute substantially to whole-lake carbon fluxes, especially in shallow lakes. Furthermore, both benthic and pelagic autotrophic and bacterial production are highly edible and of sufficient nutritional quality for animal consumers. We thus hypothesised that pelagic and benthic transfer efficiencies (ratios of production at adjacent trophic levels) in shallow lakes should be similar. We performed whole ecosystem studies in two shallow lakes (3.5ha, mean depth 2m), one with and one without submerged macrophytes, and quantified pelagic and benthic biomass, production and transfer efficiencies for bacteria, phytoplankton, epipelon, epiphyton, macrophytes, zooplankton, macrozoobenthos and fish. We expected higher transfer efficiencies in the lake with macrophytes, because these provide shelter and food for macrozoobenthos and may thus enable a more efficient conversion of basal production to consumer production. In both lakes, the majority of the whole-lake autotrophic and bacterial production was provided by benthic organisms, but whole-lake primary consumer production mostly relied on pelagic autotrophic and bacterial production. Consequently, transfer efficiency of benthic autotrophic and bacterial production to macrozoobenthos production was an order of magnitude lower than the transfer efficiency of pelagic autotrophic and bacterial production to rotifer and crustacean production. Between-lake differences in transfer efficiencies were minor. We discuss several aspects potentially causing the unexpectedly low benthic transfer efficiencies, such as the food quality of producers, pelagic-benthic links, oxygen concentrations in the deeper lake areas and additional unaccounted consumer production by pelagic and benthic protozoa and meiobenthos at intermediate or top trophic levels. None of these processes convincingly explain the large differences between benthic and pelagic transfer efficiencies. Our data indicate that shallow eutrophic lakes, even with a major share of autotrophic and bacterial production in the benthic zone, can function as pelagic systems with respect to primary consumer production. We suggest that the benthic autotrophic production was mostly transferred to benthic bacterial production, which remained in the sediments, potentially cycling internally in a similar way to what has previously been described for the microbial loop in pelagic habitats. Understanding the energetics of whole-lake food webs, including the fate of the substantial benthic bacterial production, which is either mineralised at the sediment surface or permanently buried, has important implications for regional and global carbon cycling. KW - bacterial production KW - benthic food chain KW - pelagic food chain KW - quantitative food webs KW - trophic transfer efficiency Y1 - 2017 U6 - https://doi.org/10.1111/fwb.12979 SN - 0046-5070 SN - 1365-2427 VL - 62 SP - 1693 EP - 1706 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Attermeyer, Katrin A1 - Grossart, Hans-Peter A1 - Flury, Sabine A1 - Premke, Katrin T1 - Bacterial processes and biogeochemical changes in the water body of kettle holes - mainly driven by autochthonous organic matter? JF - Aquatic sciences : research across boundaries N2 - Kettle holes are small inland waters formed from glacially-created depressions often situated in agricultural landscapes. Due to their high perimeter-to-area ratio facilitating a high aquatic-terrestrial coupling, kettle holes can accumulate high concentrations of organic carbon and nutrients, fueling microbial activities and turnover rates. Thus, they represent hotspots of carbon turnover in the landscape, but their bacterial activities and controlling factors have not been well investigated. Therefore, we aimed to assess the relative importance of various environmental factors on bacterial and biogeochemical processes in the water column of kettle holes and to disentangle their variations. In the water body of ten kettle holes in north-eastern Germany, we measured several physico-chemical and biological parameters such as carbon quantity and quality, as well as bacterial protein production (BP) and community respiration (CR) in spring, early summer and autumn 2014. Particulate organic matter served as an indicator of autochthonous production and represented an important parameter to explain variations in BP and CR. This notion is supported by qualitative absorbance indices of dissolved molecules in water samples and C: N ratios of the sediments, which demonstrate high fractions of autochthonous organic matter (OM) in the studied kettle holes. In contrast, dissolved chemical parameters were less important for bacterial activities although they revealed strong differences throughout the growing season. Pelagic bacterial activities and dynamics might thus be regulated by autochthonous OM in kettle holes implying a control of important biogeochemical processes by internal primary production rather than facilitated exchange with the terrestrial surrounding due to a high perimeter-to-area ratio. KW - Bacterial production KW - Carbon turnover KW - Growth efficiency KW - Ponds KW - Respiration KW - DOC quality KW - LC-OCD Y1 - 2017 U6 - https://doi.org/10.1007/s00027-017-0528-1 SN - 1015-1621 SN - 1420-9055 VL - 79 SP - 675 EP - 687 PB - Springer CY - Basel ER - TY - JOUR A1 - Wurzbacher, Christian A1 - Attermeyer, Katrin A1 - Kettner, Marie Therese A1 - Flintrop, Clara A1 - Warthmann, Norman A1 - Hilt, Sabine A1 - Grossart, Hans-Peter A1 - Monaghan, Michael T. T1 - DNA metabarcoding of unfractionated water samples relates phyto-, zoo- and bacterioplankton dynamics and reveals a single-taxon bacterial bloom JF - Environmental microbiology reports N2 - Most studies of aquatic plankton focus on either macroscopic or microbial communities, and on either eukaryotes or prokaryotes. This separation is primarily for methodological reasons, but can overlook potential interactions among groups. Here we tested whether DNA metabarcoding of unfractionated water samples with universal primers could be used to qualitatively and quantitatively study the temporal dynamics of the total plankton community in a shallow temperate lake. Significant changes in the relative proportions of normalized sequence reads of eukaryotic and prokaryotic plankton communities over a 3-month period in spring were found. Patterns followed the same trend as plankton estimates measured using traditional microscopic methods. The bloom of a conditionally rare bacterial taxon belonging to Arcicella was characterized, which rapidly came to dominate the whole lake ecosystem and would have remained unnoticed without metabarcoding. The data demonstrate the potential of universal DNA metabarcoding applied to unfractionated samples for providing a more holistic view of plankton communities. Y1 - 2017 U6 - https://doi.org/10.1111/1758-2229.12540 SN - 1758-2229 VL - 9 SP - 383 EP - 388 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Hornak, Karel A1 - Kasalicky, Vojtech A1 - Simek, Karel A1 - Grossart, Hans-Peter T1 - Strain-specific consumption and transformation of alga-derived dissolved organic matter by members of the Limnohabitans-C and Polynucleobacter-B clusters of Betaproteobacteria JF - Environmental microbiology N2 - We investigated changes in quality and quantity of extracellular and biomass-derived organic matter (OM) from three axenic algae (genera Rhodomonas, Chlamydomonas, Coelastrum) during growth of Limnohabitans parvus, Limnohabitans planktonicus and Polynucleobacter acidiphobus representing important clusters of freshwater planktonic Betaproteobacteria. Total extracellular and biomass-derived OM concentrations from each alga were approximately 20 mg l(-1) and 1 mg l(-1) respectively, from which up to 9% could be identified as free carbohydrates, polyamines, or free and combined amino acids. Carbohydrates represented 54%-61% of identified compounds of the extracellular OM from each alga. In biomass-derived OM of Rhodomonas and Chlamydomonas 71%-77% were amino acids and polyamines, while in that of Coelastrum 85% were carbohydrates. All bacteria grew on alga-derived OM of Coelastrum, whereas only Limnohabitans strains grew on OM from Rhodomonas and Chlamydomonas. Bacteria consumed 24%-76% and 38%-82% of all identified extracellular and biomass-derived OM compounds respectively, and their consumption was proportional to the concentration of each OM compound in the different treatments. The bacterial biomass yield was higher than the total identifiable OM consumption indicating that bacteria also utilized other unidentified alga-derived OM compounds. Bacteria, however, also produced specific OM compounds suggesting enzymatic polymer degradation or de novo exudation. Y1 - 2017 U6 - https://doi.org/10.1111/1462-2920.13900 SN - 1462-2912 SN - 1462-2920 VL - 19 SP - 4519 EP - 4535 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Kettner, Marie Therese A1 - Rojas-Jimenez, Keilor A1 - Oberbeckmann, Sonja A1 - Labrenz, Matthias A1 - Grossart, Hans-Peter T1 - Microplastics alter composition of fungal communities in aquatic ecosystems JF - Environmental microbiology N2 - Despite increasing concerns about microplastic (MP) pollution in aquatic ecosystems, there is insufficient knowledge on how MP affect fungal communities. In this study, we explored the diversity and community composition of fungi attached to polyethylene (PE) and polystyrene (PS) particles incubated in different aquatic systems in north-east Germany: the Baltic Sea, the River Warnow and a wastewater treatment plant. Based on next generation 18S rRNA gene sequencing, 347 different operational taxonomic units assigned to 81 fungal taxa were identified on PE and PS. The MP-associated communities were distinct from fungal communities in the surrounding water and on the natural substrate wood. They also differed significantly among sampling locations, pointing towards a substrate and location specific fungal colonization. Members of Chytridiomycota, Cryptomycota and Ascomycota dominated the fungal assemblages, suggesting that both parasitic and saprophytic fungi thrive in MP biofilms. Thus, considering the worldwide increasing accumulation of plastic particles as well as the substantial vector potential of MP, especially these fungal taxa might benefit from MP pollution in the aquatic environment with yet unknown impacts on their worldwide distribution, as well as biodiversity and food web dynamics at large. Y1 - 2017 U6 - https://doi.org/10.1111/1462-2920.13891 SN - 1462-2912 SN - 1462-2920 VL - 19 SP - 4447 EP - 4459 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Amalfitano, Stefano A1 - Corno, Gianluca A1 - Eckert, Ester A1 - Fazi, Stefano A1 - Ninio, Shira A1 - Callieri, Cristiana A1 - Grossart, Hans-Peter A1 - Eckert, Werner T1 - Tracing particulate matter and associated microorganisms in freshwaters JF - Hydrobiologia : acta hydrobiologica, hydrographica, limnologica et protistologica N2 - Sediment resuspension represents a key process in all natural aquatic systems, owing to its role in nutrient cycling and transport of potential contaminants. Although suspended solids are generally accepted as an important quality parameter, current monitoring programs cover quantitative aspects only. Established methodologies do not provide information on origin, fate, and risks associated with uncontrolled inputs of solids in waters. Here we discuss the analytical approaches to assess the occurrence and ecological relevance of resuspended particulate matter in freshwaters, with a focus on the dynamics of associated contaminants and microorganisms. Triggered by the identification of specific physical-chemical traits and community structure of particle-associated microorganisms, recent findings suggest that a quantitative determination of microorganisms can be reasonably used to trace the origin of particulate matter by means of nucleic acid-based assays in different aquatic systems. KW - Total suspended solids KW - Resuspended particulate KW - Turbidity KW - Sediment traps KW - Particle-associated microorganisms KW - Pathogens Y1 - 2017 U6 - https://doi.org/10.1007/s10750-017-3260-x SN - 0018-8158 SN - 1573-5117 VL - 800 SP - 145 EP - 154 PB - Springer CY - Dordrecht ER - TY - JOUR A1 - Tang, Kam W. A1 - Flury, Sabine A1 - Grossart, Hans-Peter A1 - McGinnis, Daniel F. T1 - The Chaoborus pump: Migrating phantom midge larvae sustain hypolimnetic oxygen deficiency and nutrient internal loading in lakes JF - Water research N2 - Hypolimnetic oxygen demand in lakes is often assumed to be driven mainly by sediment microbial processes, while the role of Chaoborus larvae, which are prevalent in eutrophic lakes with hypoxic to anoxic bottoms, has been overlooked. We experimentally measured the respiration rates of C flavicans at different temperatures yielding a Q(10) of 1.44-1.71 and a respiratory quotient of 0.84-0.98. Applying the experimental data in a system analytical approach, we showed that migrating Chaoborus larvae can significantly add to the water column and sediment oxygen demand, and contribute to the observed linear relationship between water column respiration and depth. The estimated phosphorus excretion by Chaoborus in sediment is comparable in magnitude to the required phosphorus loading for eutrophication. Migrating Chaoborus larvae thereby essentially trap nutrients between the water column and the sediment, and this continuous internal loading of nutrients would delay lake remediation even when external inputs are stopped. (C) 2017 Elsevier Ltd. All rights reserved. KW - Chaoborus KW - Eutrophication KW - Oxygen KW - Nutrient KW - Remediation Y1 - 2017 U6 - https://doi.org/10.1016/j.watres.2017.05.058 SN - 0043-1354 VL - 122 SP - 36 EP - 41 PB - Elsevier CY - Oxford ER - TY - JOUR A1 - Ionescu, Danny A1 - Bizic-Ionescu, Mina A1 - De Maio, Nicola A1 - Cypionka, Heribert A1 - Grossart, Hans-Peter T1 - Community-like genome in single cells of the sulfur bacterium Achromatium oxaliferum JF - Nature Communications Y1 - 2017 U6 - https://doi.org/10.1038/s41467-017-00342-9 SN - 2041-1723 VL - 8 SP - 9193 EP - 9205 PB - Nature Publ. Group CY - London ER -