TY - JOUR A1 - Ilicic, Doris A1 - Woodhouse, Jason A1 - Karsten, Ulf A1 - Zimmermann, Jonas A1 - Wichard, Thomas A1 - Quartino, Maria Liliana A1 - Campana, Gabriela Laura A1 - Livenets, Alexandra A1 - Van den Wyngaert, Silke A1 - Grossart, Hans-Peter T1 - Antarctic Glacial Meltwater Impacts the Diversity of Fungal Parasites Associated With Benthic Diatoms in Shallow Coastal Zones JF - Frontiers in microbiology N2 - Aquatic ecosystems are frequently overlooked as fungal habitats, although there is increasing evidence that their diversity and ecological importance are greater than previously considered. Aquatic fungi are critical and abundant components of nutrient cycling and food web dynamics, e.g., exerting top-down control on phytoplankton communities and forming symbioses with many marine microorganisms. However, their relevance for microphytobenthic communities is almost unexplored. In the light of global warming, polar regions face extreme changes in abiotic factors with a severe impact on biodiversity and ecosystem functioning. Therefore, this study aimed to describe, for the first time, fungal diversity in Antarctic benthic habitats along the salinity gradient and to determine the co-occurrence of fungal parasites with their algal hosts, which were dominated by benthic diatoms. Our results reveal that Ascomycota and Chytridiomycota are the most abundant fungal taxa in these habitats. We show that also in Antarctic waters, salinity has a major impact on shaping not just fungal but rather the whole eukaryotic community composition, with a diversity of aquatic fungi increasing as salinity decreases. Moreover, we determined correlations between putative fungal parasites and potential benthic diatom hosts, highlighting the need for further systematic analysis of fungal diversity along with studies on taxonomy and ecological roles of Chytridiomycota. KW - Antarctica KW - aquatic fungi KW - Chytridiomycota KW - phytoplankton host KW - salinity gradient KW - Illumina amplicon sequencing KW - Carlini Station Y1 - 2022 U6 - https://doi.org/10.3389/fmicb.2022.805694 SN - 1664-302X IS - 13 PB - Frontiers Media CY - Lausanne ER - TY - JOUR A1 - Grossart, Hans-Peter A1 - Van den Wyngaert, Silke A1 - Kagami, Maiko A1 - Wurzbacher, Christian A1 - Cunliffe, Michael A1 - Rojas-Jimenz, Keilor T1 - Fungi in aquatic ecosystems JF - Nature reviews. Microbiology N2 - Fungi are phylogenetically and functionally diverse ubiquitous components of almost all ecosystems on Earth, including aquatic environments stretching from high montane lakes down to the deep ocean. Aquatic ecosystems, however, remain frequently overlooked as fungal habitats, although fungi potentially hold important roles for organic matter cycling and food web dynamics. Recent methodological improvements have facilitated a greater appreciation of the importance of fungi in many aquatic systems, yet a conceptual framework is still missing. In this Review, we conceptualize the spatiotemporal dimensions, diversity, functions and organismic interactions of fungi in structuring aquatic food webs. We focus on currently unexplored fungal diversity, highlighting poorly understood ecosystems, including emerging artificial aquatic habitats. Y1 - 2019 U6 - https://doi.org/10.1038/s41579-019-0175-8 SN - 1740-1526 SN - 1740-1534 VL - 17 IS - 6 SP - 339 EP - 354 PB - Nature Publ. Group CY - Basingstoke ER - TY - JOUR A1 - Van den Wyngaert, Silke A1 - Rojas-Jimenez, Keilor A1 - Seto, Kensuke A1 - Kagami, Maiko A1 - Grossart, Hans-Peter T1 - Diversity and Hidden Host Specificity of Chytrids Infecting Colonial Volvocacean Algae JF - Journal of Eukaryotic Microbiology N2 - Chytrids are zoosporic fungi that play an important, but yet understudied, ecological role in aquatic ecosystems. Many chytrid species have been morphologically described as parasites on phytoplankton. However, the majority of them have rarely been isolated and lack DNA sequence data. In this study we isolated and cultivated three parasitic chytrids, infecting a common volvocacean host species, Yamagishiella unicocca. To identify the chytrids, we characterized morphology and life cycle, and analyzed phylogenetic relationships based on 18S and 28S rDNA genes. Host range and specificity of the chytrids was determined by cross-infection assays with host strains, characterized by rbcL and ITS markers. We were able to confirm the identity of two chytrid strains as Endocoenobium eudorinae Ingold and Dangeardia mamillata Schroder and described the third chytrid strain as Algomyces stechlinensis gen. et sp. nov. The three chytrids were assigned to novel and phylogenetically distant clades within the phylum Chytridiomycota, each exhibiting different host specificities. By integrating morphological and molecular data of both the parasitic chytrids and their respective host species, we unveiled cryptic host-parasite associations. This study highlights that a high prevalence of (pseudo)cryptic diversity requires molecular characterization of both phytoplankton host and parasitic chytrid to accurately identify and compare host range and specificity, and to study phytoplankton-chytrid interactions in general. KW - Chytridiomycota KW - Dangeardia mamillata KW - Endocoenobium eudorinae KW - fungal parasites KW - life cycle KW - phytoplankton Y1 - 2018 U6 - https://doi.org/10.1111/jeu.12632 SN - 1066-5234 SN - 1550-7408 VL - 65 IS - 6 SP - 870 EP - 881 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Van den Wyngaert, Silke A1 - Seto, Kensuke A1 - Rojas-Jimenez, Keilor A1 - Kagami, Maiko A1 - Grossart, Hans-Peter T1 - A New Parasitic Chytrid, Staurastromyces oculus (Rhizophydiales, Staurastromy-cetaceae fam. nov.), Infecting the Freshwater Desmid Staurastrum sp. JF - Protist N2 - Chytrids are a diverse group of ubiquitous true zoosporic fungi. The recent molecular discovery of a large diversity of undescribed chytrids has raised awareness on their important, but so far understudied ecological role in aquatic ecosystems. In the pelagic zone, of both freshwater and marine ecosystems, many chytrid species have been morphologically described as parasites on almost all major groups of phytoplankton. However, the majority of these parasitic chytrids has rarely been isolated and lack DNA sequence data, resulting in a large proportion of "dark taxa" in databases. Here, we report on the isolation and in-depth morphological, molecular and host range characterization of a chytrid infecting the common freshwater desmid Staurastrum sp. We provide first insights on the metabolic activity of the different chytrid development stages by using the vital dye FUN (R)-1 (2-chloro-4-[2,3-dihydro-3-methyl-[benzo-1,3-thiazol-2-yl]-methylidene]-1-phenylquinolinium iodide). Cross infection experiments suggest that this chytrid is an obligate parasite and specific for the genus Staurastrum sp. Phylogenetic analysis, based on ITS1-5.8S-ITS2 and 28S rDNA sequences, placed it in the order Rhizophydiales. Based on the unique zoospore ultrastructure, combined with thallus morphology, and molecular phylogenetic placement, we describe this parasitic chytrid as a new genus and species Staurastromyces oculus, within a new family Staurastromycetaceae. (C) 2017 Elsevier GmbH. All rights reserved. KW - Chytrids KW - parasite KW - phytoplankton KW - Staurastromyces oculus KW - Staurastrum sp. Y1 - 2017 U6 - https://doi.org/10.1016/j.protis.2017.05.001 SN - 1434-4610 VL - 168 SP - 392 EP - 407 PB - Elsevier CY - Jena ER - TY - JOUR A1 - Frenken, Thijs A1 - Alacid, Elisabet A1 - Berger, Stella A. A1 - Bourne, Elizabeth Charlotte A1 - Gerphagnon, Melanie A1 - Großart, Hans-Peter A1 - Gsell, Alena S. A1 - Ibelings, Bas W. A1 - Kagami, Maiko A1 - Kupper, Frithjof C. A1 - Letcher, Peter M. A1 - Loyau, Adeline A1 - Miki, Takeshi A1 - Nejstgaard, Jens C. A1 - Rasconi, Serena A1 - Rene, Albert A1 - Rohrlack, Thomas A1 - Rojas-Jimenez, Keilor A1 - Schmeller, Dirk S. A1 - Scholz, Bettina A1 - Seto, Kensuke A1 - Sime-Ngando, Telesphore A1 - Sukenik, Assaf A1 - Van de Waal, Dedmer B. A1 - Van den Wyngaert, Silke A1 - Van Donk, Ellen A1 - Wolinska, Justyna A1 - Wurzbacher, Christian A1 - Agha, Ramsy T1 - Integrating chytrid fungal parasites into plankton ecology: research gaps and needs JF - Environmental microbiology N2 - Chytridiomycota, often referred to as chytrids, can be virulent parasites with the potential to inflict mass mortalities on hosts, causing e.g. changes in phytoplankton size distributions and succession, and the delay or suppression of bloom events. Molecular environmental surveys have revealed an unexpectedly large diversity of chytrids across a wide range of aquatic ecosystems worldwide. As a result, scientific interest towards fungal parasites of phytoplankton has been gaining momentum in the past few years. Yet, we still know little about the ecology of chytrids, their life cycles, phylogeny, host specificity and range. Information on the contribution of chytrids to trophic interactions, as well as co-evolutionary feedbacks of fungal parasitism on host populations is also limited. This paper synthesizes ideas stressing the multifaceted biological relevance of phytoplankton chytridiomycosis, resulting from discussions among an international team of chytrid researchers. It presents our view on the most pressing research needs for promoting the integration of chytrid fungi into aquatic ecology. Y1 - 2017 U6 - https://doi.org/10.1111/1462-2920.13827 SN - 1462-2912 SN - 1462-2920 VL - 19 SP - 3802 EP - 3822 PB - Wiley CY - Hoboken ER -