@misc{DittmannThuenemannFewerNeilan2013, author = {Dittmann-Th{\"u}nemann, Elke and Fewer, David P. and Neilan, Brett A.}, title = {Cyanobacterial toxins biosynthetic routes and evolutionary roots}, series = {FEMS microbiology reviews}, volume = {37}, journal = {FEMS microbiology reviews}, number = {1}, publisher = {Wiley-Blackwell}, address = {Hoboken}, issn = {0168-6445}, doi = {10.1111/j.1574-6976.2012.12000.x}, pages = {23 -- 43}, year = {2013}, abstract = {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.}, language = {en} } @misc{KaplanHarelKaplanLevyetal.2012, author = {Kaplan, Aaron and Harel, Moshe and Kaplan-Levy, Ruth N. and Hadas, Ora and Sukenik, Assaf and Dittmann-Th{\"u}nemann, Elke}, title = {The languages spoken in the water body (or the biological role of cyanobacterial toxins)}, series = {Frontiers in microbiology}, volume = {3}, journal = {Frontiers in microbiology}, publisher = {Frontiers Research Foundation}, address = {Lausanne}, issn = {1664-302X}, doi = {10.3389/fmicb.2012.00138}, pages = {11}, year = {2012}, abstract = {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.}, language = {en} } @article{GuljamowBarchewitzGrosseetal.2021, author = {Guljamow, Arthur and Barchewitz, Tino and Große, Rebecca and Timm, Stefan and Hagemann, Martin and Dittmann, Elke}, title = {Diel Variations of Extracellular Microcystin Influence the Subcellular Dynamics of RubisCO in Microcystis aeruginosa PCC 7806}, series = {Microorganisms : open access journal}, volume = {9}, journal = {Microorganisms : open access journal}, number = {6}, publisher = {MDPI}, address = {Basel}, issn = {2076-2607}, doi = {10.3390/microorganisms9061265}, pages = {14}, year = {2021}, abstract = {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.}, language = {en} } @misc{GuljamowBarchewitzGrosseetal.2021, author = {Guljamow, Arthur and Barchewitz, Tino and Große, Rebecca and Timm, Stefan and Hagemann, Martin and Dittmann, Elke}, title = {Diel Variations of Extracellular Microcystin Influence the Subcellular Dynamics of RubisCO in Microcystis aeruginosa PCC 7806}, series = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, journal = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, number = {1154}, issn = {1866-8372}, doi = {10.25932/publishup-52128}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-521287}, pages = {16}, year = {2021}, abstract = {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.}, language = {en} } @misc{desAulnoisReveillonRobertetal.2020, author = {des Aulnois, Maxime Georges and R{\´e}veillon, Damien and Robert, Elise and Caruana, Amandine and Briand, Enora and Guljamow, Arthur and Dittmann, Elke and Amzil, Zouher and Bormans, Myriam}, title = {Salt shock responses of Microcystis revealed through physiological, transcript, and metabolomic analyses}, series = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, number = {1130}, issn = {1866-8372}, doi = {10.25932/publishup-47240}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-472405}, pages = {20}, year = {2020}, abstract = {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.}, language = {en} } @article{desAulnoisReveillonRobertetal.2020, author = {des Aulnois, Maxime Georges and R{\´e}veillon, Damien and Robert, Elise and Caruana, Amandine and Briand, Enora and Guljamow, Arthur and Dittmann, Elke and Amzil, Zouher and Bormans, Myriam}, title = {Salt shock responses of Microcystis revealed through physiological, transcript, and metabolomic analyses}, series = {Toxins}, volume = {12}, journal = {Toxins}, number = {3}, publisher = {MDPI}, address = {Basel}, issn = {2072-6651}, doi = {10.3390/toxins12030192}, pages = {18}, year = {2020}, abstract = {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.}, language = {en} }