TY - JOUR A1 - des Aulnois, Maxime Georges A1 - Réveillon, Damien A1 - Robert, Elise A1 - Caruana, Amandine A1 - Briand, Enora A1 - Guljamow, Arthur A1 - Dittmann, Elke A1 - Amzil, Zouher A1 - Bormans, Myriam T1 - Salt shock responses of Microcystis revealed through physiological, transcript, and metabolomic analyses JF - Toxins N2 - The transfer of Microcystis aeruginosa from freshwater to estuaries has been described worldwide and salinity is reported as the main factor controlling the expansion of M. aeruginosa to coastal environments. Analyzing the expression levels of targeted genes and employing both targeted and non-targeted metabolomic approaches, this study investigated the effect of a sudden salt increase on the physiological and metabolic responses of two toxic M. aeruginosa strains separately isolated from fresh and brackish waters, respectively, PCC 7820 and 7806. Supported by differences in gene expressions and metabolic profiles, salt tolerance was found to be strain specific. An increase in salinity decreased the growth of M. aeruginosa with a lesser impact on the brackish strain. The production of intracellular microcystin variants in response to salt stress correlated well to the growth rate for both strains. Furthermore, the release of microcystins into the surrounding medium only occurred at the highest salinity treatment when cell lysis occurred. This study suggests that the physiological responses of M. aeruginosa involve the accumulation of common metabolites but that the intraspecific salt tolerance is based on the accumulation of specific metabolites. While one of these was determined to be sucrose, many others remain to be identified. Taken together, these results provide evidence that M. aeruginosa is relatively salt tolerant in the mesohaline zone and microcystin (MC) release only occurs when the capacity of the cells to deal with salt increase is exceeded. KW - Microcystis aeruginosa KW - microcystin KW - salt stress KW - metabolomic KW - transcript Y1 - 2020 U6 - https://doi.org/10.3390/toxins12030192 SN - 2072-6651 VL - 12 IS - 3 PB - MDPI CY - Basel ER - TY - JOUR A1 - Mantzouki, Evanthia A1 - Lurling, Miquel A1 - Fastner, Jutta A1 - Domis, Lisette Nicole de Senerpont A1 - Wilk-Wozniak, Elzbieta A1 - Koreiviene, Judita A1 - Seelen, Laura A1 - Teurlincx, Sven A1 - Verstijnen, Yvon A1 - Krzton, Wojciech A1 - Walusiak, Edward A1 - Karosiene, Jurate A1 - Kasperoviciene, Jurate A1 - Savadova, Ksenija A1 - Vitonyte, Irma A1 - Cillero-Castro, Carmen A1 - Budzynska, Agnieszka A1 - Goldyn, Ryszard A1 - Kozak, Anna A1 - Rosinska, Joanna A1 - Szelag-Wasielewska, Elzbieta A1 - Domek, Piotr A1 - Jakubowska-Krepska, Natalia A1 - Kwasizur, Kinga A1 - Messyasz, Beata A1 - Pelechata, Aleksandra A1 - Pelechaty, Mariusz A1 - Kokocinski, Mikolaj A1 - Garcia-Murcia, Ana A1 - Real, Monserrat A1 - Romans, Elvira A1 - Noguero-Ribes, Jordi A1 - Parreno Duque, David A1 - Fernandez-Moran, Elisabeth A1 - Karakaya, Nusret A1 - Haggqvist, Kerstin A1 - Demir, Nilsun A1 - Beklioglu, Meryem A1 - Filiz, Nur A1 - Levi, Eti E. A1 - Iskin, Ugur A1 - Bezirci, Gizem A1 - Tavsanoglu, Ulku Nihan A1 - Ozhan, Koray A1 - Gkelis, Spyros A1 - Panou, Manthos A1 - Fakioglu, Ozden A1 - Avagianos, Christos A1 - Kaloudis, Triantafyllos A1 - Celik, Kemal A1 - Yilmaz, Mete A1 - Marce, Rafael A1 - Catalan, 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 - Goncalves, Vitor A1 - Antoniou, Maria G. A1 - Tsiarta, Nikoletta A1 - McCarthy, Valerie A1 - Perello, Victor C. A1 - Feldmann, Tonu A1 - Laas, Alo A1 - Panksep, Kristel A1 - Tuvikene, Lea A1 - Gagala, Ilona A1 - Mankiewicz-Boczek, Joana A1 - Yagci, Meral Apaydin A1 - Cinar, Sakir A1 - Capkin, Kadir A1 - Yagci, 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, Tunay A1 - Soylu, Elif Neyran A1 - Maraslioglu, Faruk A1 - Napiorkowska-Krzebietke, Agnieszka A1 - Ochocka, Agnieszka A1 - Pasztaleniec, Agnieszka A1 - Antao-Geraldes, Ana M. A1 - Vasconcelos, Vitor A1 - Morais, Joao A1 - Vale, Micaela A1 - Koker, Latife A1 - Akcaalan, Reyhan A1 - Albay, Meric A1 - Maronic, Dubravka Spoljaric A1 - Stevic, Filip A1 - Pfeiffer, Tanja Zuna A1 - Fonvielle, Jeremy Andre A1 - Straile, Dietmar A1 - Rothhaupt, Karl-Otto A1 - Hansson, Lars-Anders A1 - Urrutia-Cordero, Pablo A1 - Blaha, Ludek A1 - Geris, Rodan A1 - Frankova, Marketa A1 - Kocer, 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, Tugba Ongun A1 - Tunca, Hatice A1 - OEnem, Burcin A1 - Aleksovski, Boris A1 - Krstic, Svetislav A1 - Vucelic, Itana Bokan A1 - Nawrocka, Lidia A1 - Salmi, Pauliina A1 - Machado-Vieira, Danielle A1 - de Oliveira, Alinne Gurjao A1 - Delgado-Martin, Jordi A1 - Garcia, David A1 - Cereijo, Jose Luis A1 - Goma, Joan A1 - Trapote, Mari Carmen A1 - Vegas-Vilarrubia, Teresa A1 - Obrador, Biel A1 - Grabowska, Magdalena A1 - Karpowicz, Maciej A1 - Chmura, Damian A1 - Ubeda, Barbara A1 - Angel Galvez, Jose A1 - Ozen, Arda A1 - Christoffersen, Kirsten Seestern A1 - Warming, Trine Perlt A1 - Kobos, Justyna A1 - Mazur-Marzec, Hanna A1 - Perez-Martinez, Carmen A1 - Ramos-Rodriguez, Eloisa A1 - Arvola, Lauri A1 - Alcaraz-Parraga, Pablo A1 - Toporowska, Magdalena A1 - Pawlik-Skowronska, Barbara A1 - Niedzwiecki, Michal A1 - Peczula, Wojciech A1 - Leira, Manel A1 - Hernandez, Armand A1 - Moreno-Ostos, Enrique A1 - Maria Blanco, Jose A1 - Rodriguez, Valeriano A1 - Juan Montes-Perez, Jorge A1 - Palomino, Roberto L. A1 - Rodriguez-Perez, Estela A1 - Carballeira, Rafael A1 - Camacho, Antonio A1 - Picazo, Antonio A1 - Rochera, Carlos A1 - Santamans, Anna C. A1 - Ferriol, Carmen A1 - Romo, Susana A1 - Miguel Soria, Juan A1 - Dunalska, Julita A1 - Sienska, Justyna A1 - Szymanski, Daniel A1 - Kruk, Marek A1 - Kostrzewska-Szlakowska, Iwona A1 - Jasser, Iwona A1 - Zutinic, Petar A1 - Udovic, Marija Gligora A1 - Plenkovic-Moraj, Andelka A1 - Frak, Magdalena A1 - Bankowska-Sobczak, Agnieszka A1 - Wasilewicz, Michal A1 - Ozkan, 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 JF - Toxins 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. KW - microcystin KW - anatoxin KW - cylindrospermopsin KW - temperature KW - direct effects KW - indirect effects KW - spatial distribution KW - European Multi Lake Survey Y1 - 2018 U6 - https://doi.org/10.3390/toxins10040156 SN - 2072-6651 VL - 10 IS - 4 PB - MDPI CY - Basel ER - TY - GEN A1 - Guljamow, Arthur A1 - Barchewitz, Tino A1 - Große, Rebecca A1 - Timm, Stefan A1 - Hagemann, Martin A1 - Dittmann, Elke T1 - Diel Variations of Extracellular Microcystin Influence the Subcellular Dynamics of RubisCO in Microcystis aeruginosa PCC 7806 T2 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - The ubiquitous freshwater cyanobacterium Microcystis is remarkably successful, showing a high tolerance against fluctuations in environmental conditions. It frequently forms dense blooms which can accumulate significant amounts of the hepatotoxin microcystin, which plays an extracellular role as an infochemical but also acts intracellularly by interacting with proteins of the carbon metabolism, notably with the CO2 fixing enzyme RubisCO. Here we demonstrate a direct link between external microcystin and its intracellular targets. Monitoring liquid cultures of Microcystis in a diel experiment revealed fluctuations in the extracellular microcystin content that correlate with an increase in the binding of microcystin to intracellular proteins. Concomitantly, reversible relocation of RubisCO from the cytoplasm to the cell’s periphery was observed. These variations in RubisCO localization were especially pronounced with cultures grown at higher cell densities. We replicated these effects by adding microcystin externally to cultures grown under continuous light. Thus, we propose that microcystin may be part of a fast response to conditions of high light and low carbon that contribute to the metabolic flexibility and the success of Microcystis in the field. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1154 KW - cyanobacterial bloom KW - Microcystis KW - microcystin KW - RubisCO KW - extracellular signaling Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-521287 SN - 1866-8372 IS - 1154 ER - TY - JOUR A1 - Guljamow, Arthur A1 - Barchewitz, Tino A1 - Große, Rebecca A1 - Timm, Stefan A1 - Hagemann, Martin A1 - Dittmann, Elke T1 - Diel Variations of Extracellular Microcystin Influence the Subcellular Dynamics of RubisCO in Microcystis aeruginosa PCC 7806 JF - Microorganisms : open access journal N2 - The ubiquitous freshwater cyanobacterium Microcystis is remarkably successful, showing a high tolerance against fluctuations in environmental conditions. It frequently forms dense blooms which can accumulate significant amounts of the hepatotoxin microcystin, which plays an extracellular role as an infochemical but also acts intracellularly by interacting with proteins of the carbon metabolism, notably with the CO2 fixing enzyme RubisCO. Here we demonstrate a direct link between external microcystin and its intracellular targets. Monitoring liquid cultures of Microcystis in a diel experiment revealed fluctuations in the extracellular microcystin content that correlate with an increase in the binding of microcystin to intracellular proteins. Concomitantly, reversible relocation of RubisCO from the cytoplasm to the cell’s periphery was observed. These variations in RubisCO localization were especially pronounced with cultures grown at higher cell densities. We replicated these effects by adding microcystin externally to cultures grown under continuous light. Thus, we propose that microcystin may be part of a fast response to conditions of high light and low carbon that contribute to the metabolic flexibility and the success of Microcystis in the field. KW - cyanobacterial bloom KW - Microcystis KW - microcystin KW - RubisCO KW - extracellular signaling Y1 - 2021 U6 - https://doi.org/10.3390/microorganisms9061265 SN - 2076-2607 VL - 9 IS - 6 PB - MDPI CY - Basel ER - TY - GEN A1 - des Aulnois, Maxime Georges A1 - Réveillon, Damien A1 - Robert, Elise A1 - Caruana, Amandine A1 - Briand, Enora A1 - Guljamow, Arthur A1 - Dittmann, Elke A1 - Amzil, Zouher A1 - Bormans, Myriam T1 - Salt shock responses of Microcystis revealed through physiological, transcript, and metabolomic analyses T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - The transfer of Microcystis aeruginosa from freshwater to estuaries has been described worldwide and salinity is reported as the main factor controlling the expansion of M. aeruginosa to coastal environments. Analyzing the expression levels of targeted genes and employing both targeted and non-targeted metabolomic approaches, this study investigated the effect of a sudden salt increase on the physiological and metabolic responses of two toxic M. aeruginosa strains separately isolated from fresh and brackish waters, respectively, PCC 7820 and 7806. Supported by differences in gene expressions and metabolic profiles, salt tolerance was found to be strain specific. An increase in salinity decreased the growth of M. aeruginosa with a lesser impact on the brackish strain. The production of intracellular microcystin variants in response to salt stress correlated well to the growth rate for both strains. Furthermore, the release of microcystins into the surrounding medium only occurred at the highest salinity treatment when cell lysis occurred. This study suggests that the physiological responses of M. aeruginosa involve the accumulation of common metabolites but that the intraspecific salt tolerance is based on the accumulation of specific metabolites. While one of these was determined to be sucrose, many others remain to be identified. Taken together, these results provide evidence that M. aeruginosa is relatively salt tolerant in the mesohaline zone and microcystin (MC) release only occurs when the capacity of the cells to deal with salt increase is exceeded. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1130 KW - Microcystis aeruginosa KW - microcystin KW - salt stress KW - metabolomic KW - transcript Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-472405 SN - 1866-8372 IS - 1130 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 - Svanys, Algirdas A1 - Eigemann, Falk A1 - Großart, Hans-Peter A1 - Hilt, Sabine T1 - Microcystins do not necessarily lower the sensitivity of Microcystis aeruginosa to tannic acid JF - FEMS microbiology letters N2 - Different phytoplankton strains have been shown to possess varying sensitivities towards macrophyte allelochemicals, yet the reasons for this are largely unknown. To test whether microcystin (MC) is responsible for strain-specific sensitivities of Microcystis aeruginosa to macrophyte allelochemicals, we compared the sensitivity of 12 MC- and non-MC-producing M. aeruginosa strains, including an MC-deficient mutant and its wild type, to the polyphenolic allelochemical tannic acid (TA). Non-MC-producing strains showed a significantly higher sensitivity to TA than MC-producing strains, both in Chlorophyll a concentrations and quantum yields of photosystem II. In contrast, an MC-deficient mutant displayed a higher fitness against TA compared to its wild type. These results suggest that the resistance of M. aeruginosa to polyphenolic allelochemicals is not primarily related to MCs per se, but to other yet unknown protective mechanisms related to MCs. KW - allelopathy KW - Delta mcyB mutant KW - microcystin KW - Microcystis aeruginosa KW - tannic acid Y1 - 2016 U6 - https://doi.org/10.1093/femsle/fnv227 SN - 0378-1097 SN - 1574-6968 VL - 363 SP - 53 EP - 77 PB - Oxford Univ. Press CY - Oxford ER - TY - JOUR A1 - Kaplan, Aaron A1 - Harel, Moshe A1 - Kaplan-Levy, Ruth N. A1 - Hadas, Ora A1 - Sukenik, Assaf A1 - Dittmann-Thünemann, Elke T1 - The languages spoken in the water body (or the biological role of cyanobacterial toxins) JF - Frontiers in microbiology N2 - Although intensification of toxic cyanobacterial blooms over the last decade is a matter of growing concern due to bloom impact on water quality, the biological role of most of the toxins produced is not known. In this critical review we focus primarily on the biological role of two toxins, microcystins and cylindrospermopsin, in inter- and intra-species communication and in nutrient acquisition. We examine the experimental evidence supporting some of the dogmas in the field and raise several open questions to be dealt with in future research. We do not discuss the health and environmental implications of toxin presence in the water body. KW - aoa KW - cylindrospermopsin KW - microcystin KW - cyr KW - mcy Y1 - 2012 U6 - https://doi.org/10.3389/fmicb.2012.00138 SN - 1664-302X VL - 3 PB - Frontiers Research Foundation CY - Lausanne ER - TY - JOUR A1 - Dittmann-Thünemann, Elke A1 - Fewer, David P. A1 - Neilan, Brett A. T1 - Cyanobacterial toxins biosynthetic routes and evolutionary roots JF - FEMS microbiology reviews N2 - Cyanobacteria produce an unparalleled variety of toxins that can cause severe health problems or even death in humans, and wild or domestic animals. In the last decade, biosynthetic pathways have been assigned to the majority of the known toxin families. This review summarizes current knowledge about the enzymatic basis for the production of the hepatotoxins microcystin and nodularin, the cytotoxin cylindrospermopsin, the neurotoxins anatoxin and saxitoxin, and the dermatotoxin lyngbyatoxin. Elucidation of the biosynthetic pathways of the toxins has paved the way for the development of molecular techniques for the detection and quantification of the producing cyanobacteria in different environments. Phylogenetic analyses of related clusters from a large number of strains has also allowed for the reconstruction of the evolutionary scenarios that have led to the emergence, diversification, and loss of such gene clusters in different strains and genera of cyanobacteria. Advances in the understanding of toxin biosynthesis and evolution have provided new methods for drinking-water quality control and may inspire the development of techniques for the management of bloom formation in the future. KW - microcystin KW - cylindrospermopsin KW - anatoxin KW - saxitoxin KW - cyanobacteria Y1 - 2013 U6 - https://doi.org/10.1111/j.1574-6976.2012.12000.x SN - 0168-6445 SN - 1574-6976 VL - 37 IS - 1 SP - 23 EP - 43 PB - Wiley-Blackwell CY - Hoboken ER - TY - THES A1 - Makower, Katharina T1 - The roles of secondary metabolites in microcystis inter-strain interactions T1 - Die Rolle von Sekundärmetaboliten in den Wechselbeziehungen zwischen Microcystis-Stämmen N2 - Among the bloom-forming and potentially harmful cyanobacteria, the genus Microcystis represents a most diverse taxon, on the genomic as well as on morphological and secondary metabolite levels. Microcystis communities are composed of a variety of diversified strains. The focus of this study lies on potential interactions between Microcystis representatives and the roles of secondary metabolites in these interaction processes. The role of secondary metabolites functioning as signaling molecules in the investigated interactions is demonstrated exemplary for the prevalent hepatotoxin microcystin. The extracellular and intracellular roles of microcystin are tested in microarray-based transcriptomic approaches. While an extracellular effect of microcystin on Microcystis transcription is confirmed and connected to a specific gene cluster of another secondary metabolite in this study, the intracellularly occurring microcystin is related with several pathways of the primary metabolism. A clear correlation of a microcystin knockout and the SigE-mediated regulation of carbon metabolism is found. According to the acquired transcriptional data, a model is proposed that postulates the regulating effect of microcystin on transcriptional regulators such as the alternative sigma factor SigE, which in return captures an essential role in sugar catabolism and redox-state regulation. For the purpose of simulating community conditions as found in the field, Microcystis colonies are isolated from the eutrophic lakes near Potsdam, Germany and established as stably growing under laboratory conditions. In co-habitation simulations, the recently isolated field strain FS2 is shown to specifically induce nearly immediate aggregation reactions in the axenic lab strain Microcystis aeruginosa PCC 7806. In transcriptional studies via microarrays, the induced expression program in PCC 7806 after aggregation induction is shown to involve the reorganization of cell envelope structures, a highly altered nutrient uptake balance and the reorientation of the aggregating cells to a heterotrophic carbon utilization, e.g. via glycolysis. These transcriptional changes are discussed as mechanisms of niche adaptation and acclimation in order to prevent competition for resources. N2 - Die Gattung Microcystis stellt unter den blüten-bildenden Cyanobakterien ein Taxon besonderer Diversität dar. Dies gilt sowohl für die Genomstruktur als auch für morphologische Charakteristika und Sekundärmetabolite. Microcystis-Communities weisen eine Zusammensetzung aus einer Vielzahl von diversifizierten Stämmen auf. Das Hauptaugenmerk dieser Arbeit lag darauf, potentielle Wechselwirkungen zwischen Microcystis-Vertretern zu charakterisieren und die Rolle von Sekundärmetaboliten in Interaktions-Prozessen zu untersuchen. Die Rolle von Sekundärmetaboliten als Signalstoffe in Microcystis-Interaktionen wurde exemplarisch für das Hepatotoxin Microcystin demonstriert. Sowohl die extrazelluläre als auch die intrazellulare Funktion von Microcystin wurde anhand von Microarray-basierten Transkriptomstudien getestet. Dabei konnte eine extrazelluläre Wirkung von Microcystin bestätigt werden und mit der Transkription eines spezifischen anderen Sekundärmetaboliten in Verbindung gebracht werden. Intrazellulär vorkommendes Microcystin wurde hingegen mit verschiedenen Stoffwechselwegen des Primärstoffwechsels verknüpft. Es konnte ein deutlicher Zusammenhang zwischen einem Microcystin-Knockout und der SigE-vermittelten Regulation des Kohlenstoffmetabolismus festgestellt werden. Anhand der erworbenen Transkriptionsdaten wurde ein Modell vorgeschlagen, das eine regulierende Wirkung von Microcystin auf Transkriptionsfaktoren wie den alternativen Sigmafaktor SigE postuliert, welcher seinerseits eine zentrale Rolle in Zuckerabbauprozessen und zellulärer Redoxregulation einnimmt. Mit dem Ziel, Community-ähnliche Bedingungen zu simulieren, wurden Microcystis-Freiland-Kolonien aus eutrophen Gewässern in der Umgebung von Potsdam isoliert und ein stabiles Wachstum unter Laborbedingungen etabliert. Es konnte gezeigt werden, dass der frisch isolierte Freilandstamm FS2 spezifisch eine starke Zellaggregation in Microcystis aeruginosa PCC 7806 (einem axenischen Labortstamm) auslösen konnte. In Transkriptionsstudien mit Hilfe von Microarrays wurden Expressionsprogramme gefunden, die sowohl einen Umbau von Zellhüllstrukturen, als auch einen stark veränderten transmembranen Nährstofftransport beinhalteten. Darüber hinaus konnte in den aggregierenden PCC 7806-Zellen eine Verlagerung zu heterotrophen Kohlenstoffabbauprozessen wie der Glykolyse gefunden werden. Die transkriptionellen Veränderungen wurden als Akklimationsmechanismen zur Positionierung in ökologische Nischen diskutiert, um Konkurrenzen um Ressourcen zu vermeiden. KW - microcystis KW - microcystin KW - secondary metabolites KW - transcriptomics KW - interactions KW - Sekundärmetabolite KW - Transkriptomik KW - Wechselwirkungen Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-93916 ER - TY - THES A1 - Meissner, Sven T1 - Implications of Microcystin Production in Microcystis aeruginosa PCC 7806 T1 - Effekte der Produktion von Microcystin in Microcystis aeruginosa PCC 7806 N2 - Cyanobacteria produce about 40 percent of the world’s primary biomass, but also a variety of often toxic peptides such as microcystin. Mass developments, so called blooms, can pose a real threat to the drinking water supply in many parts of the world. This study aimed at characterizing the biological function of microcystin production in one of the most common bloom-forming cyanobacterium Microcystis aeruginosa. In a first attempt, the effect of elevated light intensity on microcystin production and its binding to cellular proteins was studied. Therefore, conventional microcystin quantification techniques were combined with protein-biochemical methods. RubisCO, the key enzyme for primary carbon fixation was a major microcystin interaction partner. High light exposition strongly stimulated microcystin-protein interactions. Up to 60 percent of the total cellular microcystin was detected bound to proteins, i.e. inaccessible for standard quantification procedures. Underestimation of total microcystin contents when neglecting the protein fraction was also demonstrated in field samples. Finally, an immuno-fluorescence based method was developed to identify microcystin producing cyanobacteria in mixed populations. The high light induced microcystin interaction with proteins suggested an impact of the secondary metabolite on the primary metabolism of Microcystis by e.g. modulating the activity of enzymes. For addressing that question, a comprehensive GC/MS-based approach was conducted to compare the accumulation of metabolites in the wild-type of Microcystis aeruginosa PCC 7806 and the microcystin deficient ΔmcyB mutant. From all 501 detected non-redundant metabolites 85 (17 percent) accumulated significantly different in either of both genotypes upon high light exposition. Accumulation of compatible solutes in the ΔmcyB mutant suggests a role of microcystin in fine-tuning the metabolic flow to prevent stress related to excess light, high oxygen concentration and carbon limitation. Co-analysis of the widely used model cyanobacterium Synechocystis PCC 6803 revealed profound metabolic differences between species of cyanobacteria. Whereas Microcystis channeled more resources towards carbohydrate synthesis, Synechocystis invested more in amino acids. These findings were supported by electron microscopy of high light treated cells and the quantification of storage compounds. While Microcystis accumulated mainly glycogen to about 8.5 percent of its fresh weight within three hours, Synechocystis produced higher amounts of cyanophycin. The results showed that the characterization of species-specific metabolic features should gain more attention with regard to the biotechnological use of cyanobacteria. N2 - Cyanobakterien produzieren etwa 40 Prozent der primären Biomasse auf der Welt aber auch giftige Peptide wie das leberschädigende Microcystin. Massenvorkommen, so genannte Blaualgenblüten, gefährden vielerorts regelmäßig die Trinkwasserversorgung. Diese Arbeit hatte zum Ziel, den Einfluss der Microcystinproduktion auf physiologische Abläufe in dem weit verbreiteten blütenbildenden Cyanobakterium Microcystis aeruginosa zu charakterisieren. Zum einen, wurde hierfür der Einfluss der Beleuchtungsintensität auf die Produktion von Microcystin und dessen Bindung an zelluläre Proteine ermittelt. Hierzu wurden etablierte Quantifizierungstechniken mit biochemischen Methoden kombiniert. RubisCO, das Schlüsselenzym zur primären Kohlenstofffixierung, war ein Hauptinteraktionspartner von Microcystin. Hohe Beleuchtungsintensität erhöhte die Menge von an Proteine gebundenem Microcystin. Bis zu 60 Prozent des gesamten zellulären Microcystins lag an Proteine gebunden vor, d.h. es wurde durch Standardquantifizierungsmethoden nicht erfasst. Die Notwendigkeit, zur Quantifizierung des gesamten Microcystins die Proteinfraktion mit einzubeziehen, wurde auch in Freilandproben demonstriert. Die Entwicklung einer immunofluoreszenzbasierten Methode erlaubte die Unterscheidung von toxischen und nichttoxischen Microcystis-Kolonien in Freilandproben. Die starklichtinduzierte Interaktion von Microcystin mit Proteinen deutete auf einen möglichen Einfluss des Sekundärmetabolits auf den Primärstoffwechsel von Microcystis hin. Um dieser Frage nachzugehen, wurde ein umfassender GC/MS-basierter Versuch durchgeführt, um die Akkumulation von Metaboliten im Microcystin produzierenden Stamm Microcystis aeruginosa PCC 7806 und dessen microcystinfreier ΔmcyB-mutierten Variante vergleichen zu können. Es zeigte sich, dass Microcystin einen Einfluss auf die Akkumulation von 85 (17 Prozent) aller 501 detektierten Metaboliten unter erhöhter Beleuchtungsstärke hatte. Besonders die vermehrte Synthese osmotisch aktiver Substanzen in der ΔmcyB Mutante, verstanden als generelle Reaktion auf allgemeinen Stress, deutete auf eine Beteiligung von Microcystin in der metabolischen Justierung von Microcystis hin. Die Parallelanalyse des Modellstamms Synechocystis PCC 6803 offenbarte grundsätzliche metabolische Unterschiede zwischen verschiedenen Cyanobakterienspezies. Demnach produzierte Microcystis vor allem Kohlehydrate und Synechocystis eher Aminosäuren. Die GC/MS-basierten Ergebnisse wurden durch elektronmikroskopische Aufnahmen und die Quantifizierung von Speichermetaboliten gestützt. Innerhalb drei Stunden bewirkte Starklicht die Akkumulation von Glykogen in Microcystis auf ca. 8.5 Prozent des Frischgewichts, wohingegen Synechocystis mehr Cyanophycin produzierte. Die Ergebnisse zeigten, dass im Hinblick auf die biotechnologische Nutzung von Cyanobakterien, die Charakterisierung speziesspezifischer metabolischer Eigenschaften mehr Beachtung finden sollte. KW - microcystin KW - Microcystin KW - cyanobacteria KW - Cyanobakterien Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-75199 ER -