@article{MasigolKhodaparastWoodhouseetal.2019, author = {Masigol, Hossein and Khodaparast, Seyed Akbar and Woodhouse, Jason Nicholas and Rojas Jim{\´e}nez, Keilor and Fonvielle, Jeremy Andre and Rezakhani, Forough and Mostowfizadeh-Ghalamfarsa, Reza and Neubauer, Darshan and Goldhammer, Tobias and Grossart, Hans-Peter}, title = {The contrasting roles of aquatic fungi and oomycetes in the degradation and transformation of polymeric organic matter}, series = {Limnology and oceanography}, volume = {64}, journal = {Limnology and oceanography}, number = {6}, publisher = {Wiley}, address = {Hoboken}, issn = {0024-3590}, pages = {2662 -- 2678}, year = {2019}, abstract = {Studies on the ecological role of fungi and, to a lesser extent, oomycetes, are receiving increasing attention, mainly due to their participation in the cycling of organic matter in aquatic ecosystems. To unravel their importance in humification processes, we isolated several strains of fungi and oomycetes from Anzali lagoon, Iran. We then performed taxonomic characterization by morphological and molecular methods, analyzed the ability to degrade several polymeric substrates, performed metabolic fingerprinting with Ecoplates, and determined the degradation of humic substances (HS) using liquid chromatography-organic carbon detection. Our analyses highlighted the capacity of aquatic fungi to better degrade a plethora of organic molecules, including complex polymers. Specifically, we were able to demonstrate not only the utilization of these complex polymers, but also the role of fungi in the production of HS. In contrast, oomycetes, despite some morphological and physiological similarities with aquatic fungi, exhibited a propensity toward opportunism, quickly benefitting from the availability of small organic molecules, while exhibiting sensitivity toward more complex polymers. Despite their contrasting roles, our study highlights the importance of both oomycetes and fungi in aquatic organic matter transformation and cycling with potential implications for the global carbon cycle.}, language = {en} } @misc{DommainAndamaMcDonoughetal.2020, author = {Dommain, Ren{\´e} and Andama, Morgan and McDonough, Molly M. and Prado, Natalia A. and Goldhammer, Tobias and Potts, Richard and Maldonado, Jes{\´u}s E. and Nkurunungi, John Bosco and Campana, Michael G.}, title = {The Challenges of Reconstructing Tropical Biodiversity With Sedimentary Ancient DNA}, series = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, number = {970}, issn = {1866-8372}, doi = {10.25932/publishup-47430}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-474305}, pages = {28}, year = {2020}, abstract = {Sedimentary ancient DNA has been proposed as a key methodology for reconstructing biodiversity over time. Yet, despite the concentration of Earth's biodiversity in the tropics, this method has rarely been applied in this region. Moreover, the taphonomy of sedimentary DNA, especially in tropical environments, is poorly understood. This study elucidates challenges and opportunities of sedimentary ancient DNA approaches for reconstructing tropical biodiversity. We present shotgun-sequenced metagenomic profiles and DNA degradation patterns from multiple sediment cores from Mubwindi Swamp, located in Bwindi Impenetrable Forest (Uganda), one of the most diverse forests in Africa. We describe the taxonomic composition of the sediments covering the past 2200 years and compare the sedimentary DNA data with a comprehensive set of environmental and sedimentological parameters to unravel the conditions of DNA degradation. Consistent with the preservation of authentic ancient DNA in tropical swamp sediments, DNA concentration and mean fragment length declined exponentially with age and depth, while terminal deamination increased with age. DNA preservation patterns cannot be explained by any environmental parameter alone, but age seems to be the primary driver of DNA degradation in the swamp. Besides degradation, the presence of living microbial communities in the sediment also affects DNA quantity. Critically, 92.3\% of our metagenomic data of a total 81.8 million unique, merged reads cannot be taxonomically identified due to the absence of genomic references in public databases. Of the remaining 7.7\%, most of the data (93.0\%) derive from Bacteria and Archaea, whereas only 0-5.8\% are from Metazoa and 0-6.9\% from Viridiplantae, in part due to unbalanced taxa representation in the reference data. The plant DNA record at ordinal level agrees well with local pollen data but resolves less diversity. Our animal DNA record reveals the presence of 41 native taxa (16 orders) including Afrotheria, Carnivora, and Ruminantia at Bwindi during the past 2200 years. Overall, we observe no decline in taxonomic richness with increasing age suggesting that several-thousand-year-old information on past biodiversity can be retrieved from tropical sediments. However, comprehensive genomic surveys of tropical biota need prioritization for sedimentary DNA to be a viable methodology for future tropical biodiversity studies.}, language = {en} } @article{DommainAndamaMcDonoughetal.2020, author = {Dommain, Ren{\´e} and Andama, Morgan and McDonough, Molly M. and Prado, Natalia A. and Goldhammer, Tobias and Potts, Richard and Maldonado, Jes{\´u}s E. and Nkurunungi, John Bosco and Campana, Michael G.}, title = {The Challenges of Reconstructing Tropical Biodiversity With Sedimentary Ancient DNA}, series = {Frontiers in Ecology and Evolution}, volume = {8}, journal = {Frontiers in Ecology and Evolution}, publisher = {Frontiers Media}, address = {Lausanne}, issn = {2296-701X}, doi = {10.3389/fevo.2020.00218}, pages = {26}, year = {2020}, abstract = {Sedimentary ancient DNA has been proposed as a key methodology for reconstructing biodiversity over time. Yet, despite the concentration of Earth's biodiversity in the tropics, this method has rarely been applied in this region. Moreover, the taphonomy of sedimentary DNA, especially in tropical environments, is poorly understood. This study elucidates challenges and opportunities of sedimentary ancient DNA approaches for reconstructing tropical biodiversity. We present shotgun-sequenced metagenomic profiles and DNA degradation patterns from multiple sediment cores from Mubwindi Swamp, located in Bwindi Impenetrable Forest (Uganda), one of the most diverse forests in Africa. We describe the taxonomic composition of the sediments covering the past 2200 years and compare the sedimentary DNA data with a comprehensive set of environmental and sedimentological parameters to unravel the conditions of DNA degradation. Consistent with the preservation of authentic ancient DNA in tropical swamp sediments, DNA concentration and mean fragment length declined exponentially with age and depth, while terminal deamination increased with age. DNA preservation patterns cannot be explained by any environmental parameter alone, but age seems to be the primary driver of DNA degradation in the swamp. Besides degradation, the presence of living microbial communities in the sediment also affects DNA quantity. Critically, 92.3\% of our metagenomic data of a total 81.8 million unique, merged reads cannot be taxonomically identified due to the absence of genomic references in public databases. Of the remaining 7.7\%, most of the data (93.0\%) derive from Bacteria and Archaea, whereas only 0-5.8\% are from Metazoa and 0-6.9\% from Viridiplantae, in part due to unbalanced taxa representation in the reference data. The plant DNA record at ordinal level agrees well with local pollen data but resolves less diversity. Our animal DNA record reveals the presence of 41 native taxa (16 orders) including Afrotheria, Carnivora, and Ruminantia at Bwindi during the past 2200 years. Overall, we observe no decline in taxonomic richness with increasing age suggesting that several-thousand-year-old information on past biodiversity can be retrieved from tropical sediments. However, comprehensive genomic surveys of tropical biota need prioritization for sedimentary DNA to be a viable methodology for future tropical biodiversity studies.}, language = {en} }