A5021079016- Methane Hydrates and Related Phenomena
- Climate change and permafrost
- Microbial Community Ecology and Physiology
- Polar Research and Ecology
- Cryospheric studies and observations
- Atmospheric and Environmental Gas Dynamics
- Peatlands and Wetlands Ecology
- Hydrocarbon exploration and reservoir analysis
- Geological Studies and Exploration
- Geology and Paleoclimatology Research
- Genomics and Phylogenetic Studies
- Insect and Pesticide Research
- Insect Utilization and Effects
- Coastal wetland ecosystem dynamics
- Indigenous Studies and Ecology
- Arctic and Antarctic ice dynamics
- Protist diversity and phylogeny
- Marine Biology and Ecology Research
- Identification and Quantification in Food
- Cephalopods and Marine Biology
- Insect and Arachnid Ecology and Behavior
- Advanced Chemical Sensor Technologies
- Wastewater Treatment and Nitrogen Removal
- Gut microbiota and health
- Metal Extraction and Bioleaching
Federal Institute for Risk Assessment
2022-2025
GFZ Helmholtz Centre for Geosciences
2016-2023
Centre de Géosciences
2020
University of Alaska Fairbanks
2018-2019
Max Planck Institute for Marine Microbiology
2010-2016
Max Planck Society
2013
Methanogenic archaea are important for the global greenhouse gas budget since they produce methane under anoxic conditions in numerous natural environments such as oceans, estuaries, soils, and lakes. Whether how environmental change will propagate into methanogenic assemblages of remains largely unknown owing to a poor understanding distribution patterns drivers this specific group microorganisms. In study, we performed meta-analysis targeting biogeographic controls communities using 94...
Thawing submarine permafrost is a source of methane to the subsurface biosphere. Methane oxidation in sediments has been proposed, but responsible microorganisms remain uncharacterized. We analyzed archaeal communities and identified distinct anaerobic methanotrophic assemblages marine terrestrial origin (ANME-2a/b, ANME-2d) both frozen completely thawed sediments. Besides archaea potentially involved (AOM) we found large diversity mainly belonging Bathyarchaeota, Thaumarchaeota,...
Blooms of microalgae on glaciers and ice sheets are amplifying surface melting rates, which already affected by climate change. Most studies glacial microorganisms (including snow glacier algae) have so far focused the spring summer melt season, leading to a temporal bias, knowledge gap in our understanding variations microbial diversity, productivity, physiology surfaces year-round. Here, we investigated communities from Icelandic bare habitats, with sampling spanning two consecutive years...
Abstract Nitrogen regulates multiple aspects of the permafrost climate feedback, including plant growth, organic matter decomposition, and production potent greenhouse gas nitrous oxide. Despite its importance, current estimates nitrogen are highly uncertain. Here, we compiled a dataset >2000 samples to quantify stocks in Yedoma domain, region with organic-rich that contains ~25% all carbon. We estimate domain 41.2 gigatons down ~20 metre for deepest unit, which increases previous entire...
The organic carbon of permafrost affected soils is receiving particular attention with respect to its fate and potential feedback global warming. structural activity changes methanogenic communities in the degrading permafrost-affected wetlands on Tibetan Plateau can serve as fundamental elements for modelling interaction ecosystems climate change. Hence, we aimed at anticipating if how rapid environmental occurring especially high altitude platform will affect communities. We identified...
Ferruginous (Fe-rich, SO4 -poor) conditions are generally restricted to freshwater sediments on Earth today, but were likely widespread during the Archean and Proterozoic Eons. Lake Towuti, Indonesia, is a large ferruginous lake that hosts geochemical processes analogous those operated in ocean. The metabolic potential of microbial communities related biogeochemical cycling under such remain largely unknown. We combined measurements (pore water chemistry, sulfate reduction rates) with...
Abstract. The rewetting of drained peatlands alters peat geochemistry and often leads to sustained elevated methane emission. Although this is produced entirely by microbial activity, the distribution abundance methane-cycling microbes in rewetted peatlands, especially fens, rarely described. In study, we compare community composition relation porewater two fens northeastern Germany, a coastal brackish fen freshwater riparian fen, with known high fluxes. We utilized 16S rRNA high-throughput...
Abstract. In natural coastal wetlands, high supplies of marine sulfate suppress methanogenesis. Coastal wetlands are, however, often subject to disturbance by diking and drainage for agricultural use can turn potent methane sources when rewetted remediation. This suggests that preceding land measures suspend the sulfate-related suppressing mechanisms. Here, we unravel hydrological relocation biogeochemical S C transformation processes induced emissions in a disturbed peatland despite former...
Abstract Glacier and ice sheet surfaces host diverse communities of microorganisms whose activity (or inactivity) influences biogeochemical cycles melting. Supraglacial microbes endure various environmental extremes including resource scarcity, frequent temperature fluctuations above below the freezing point water, high UV irradiance during summer followed by months total darkness winter. One strategy that enables microbial life to persist through is dormancy, which despite being prevalent...
Abstract Permafrost thaw subjects previously frozen organic carbon (OC) to microbial decomposition, generating the greenhouse gases (GHG) dioxide (CO 2 ) and methane (CH 4 fueling a positive climate feedback. Over one quarter of permafrost OC is stored in deep, ice‐rich Pleistocene‐aged yedoma deposits. We used combination anaerobic incubations, sequencing, ultrahigh‐resolution mass spectrometry show biolability increases with depth along 12‐m profile. In incubations at 3 °C 13 °C, GHG...
Microbial decomposition of thawed permafrost carbon in thermokarst lakes leads to the release ancient as greenhouse gas methane (CH4), yet potential mitigating processes are not understood. Here, we report δ13C–CH4 signatures pore water a lake sediment core that points towards situ occurrence anaerobic oxidation (AOM). Analysis microbial communities showed natural enrichment CH4-oxidizing archaeal occur horizons at temperatures near 0 °C. These archaea also high rates AOM laboratory...
Effluents from wastewater treatment plants (WWTPs) containing micro-organisms and residual nitrogen can stimulate nitrification in freshwater streams. We hypothesized that different ammonia-oxidizing (AOB) nitrite-oxidizing (NOB) bacteria present WWTP effluents differ their potential to colonize biofilms the receiving In an experimental approach, we monitored biofilm colonization by nitrifiers ammonium- or nitrite-fed microcosm flumes after inoculation with activated sludge. a field study,...
Large, colorless sulfur-oxidizing bacteria (LSB) of the family Beggiatoaceae form thick mats at sulfidic sediment surfaces, where they efficiently detoxify sulfide before it enters water column. The genus Thiomargarita harbors largest known free-living with cell sizes up to 750 μm in diameter. In addition their ability oxidize reduced sulfur compounds, some spp. are store large amounts nitrate, phosphate and elemental internally. To date little is about energy yielding metabolic pathways,...
The genus Thiomargarita includes the world's largest bacteria. But as uncultured organisms, their physiology, metabolism, and basis for gigantism are not well understood. Thus, a genomics approach, applied to single Candidatus nelsonii cell was employed explore genetic potential of one these enigmatic giant obtained from an assemblage budding Ca. T. attached provannid gastropod shell Hydrate Ridge, methane seep offshore Oregon, USA. Here we present manually curated genome Bud S10 resulting...
ABSTRACT Permafrost microbial research has flourished in the past decades, due part to improvements sampling and molecular techniques, but also increased focus on permafrost greenhouse gas feedback climate change other ecological processes high latitude alpine soils. microorganisms are adapted these extreme environments remain active at low temperatures when resources limited. They an important component of global elemental cycles as they regulate organic matter turnover production,...
Abstract A real-time polymerase chain reaction (PCR)-based protocol (Gloco-PCR) was validated to specifically detect Gryllus locorojo , a species on the European market often mistaken for assimilis . Whereas latter is allowed in EU feeding farmed animals, G. only permitted pets according current legislation. The method developed basis of cytochrome oxidase I gene, (COI), which sequenced with thoroughly characterised and samples. highly sensitive, detecting 0.8 pg -DNA or 0.1% incurred feed,...
Hydrothermal sediments in the Guaymas Basin are covered by microbial mats that dominated nitrate-respiring and sulphide-oxidizing Beggiatoa. The presence of these strongly correlates with sulphide- ammonium-rich fluids venting from subsurface. Because ammonium oxygen form opposed gradients at sediment surface, we hypothesized nitrification is an active process Beggiatoa mats. Using biogeochemical molecular methods, measured determined diversity abundance nitrifiers. Nitrification rates...
Abstract Blooms of pigmented algae darken the surface glaciers and ice sheets, thereby enhancing solar energy absorption amplifying snow melt. The impacts algal pigment community composition on darkening are still poorly understood. Here, we characterise glacier signatures bare surfaces study their role in photophysiology three Southeast Greenland. Purpurogallin astaxanthin esters dominated pools (mass ratios to chlorophyll a 32 56, respectively). Algal biomass pigments impacted chromophoric...
The rare biosphere, the low abundant microbial populations, is suggested to be a conserved way of life. Here we conducted molecular survey methanogenic archaea in environment targeting mcrA gene order test if general concepts associated with structure bacterial biosphere also apply single functional groups. Similar what known about communities, contribution methanogens alpha diversity much larger than Bray-Curtis measures. Moreover, similar core group harbored by and communities suggests...
Diffuse hydrothermal fluids often contain organic compounds such as hydrocarbons, lipids, and acids. Microorganisms consuming these at sites are so far only known from cultivation-dependent studies. To identify potential heterotrophs without prior cultivation, we combined microbial community analysis with short-term incubations using 13C-labeled acetate two distinct systems. We followed cell growth assimilation of 13C into single cells by nanoSIMS fluorescence in situ hybridization (FISH)....
Abstract Northern peatlands typically develop through succession from fens dominated by the moss family Amblystegiaceae to bogs genus Sphagnum . How different plants and abiotic environmental conditions provided in peat shape respective associated microbial communities is unknown. Through a large-scale molecular biogeochemical study spanning Arctic, sub-Arctic temperate regions we assessed how endo- epiphytic of natural northern peatland mosses relate type ( Amblystegiaceae), location, taxa...
Abstract. Arctic regions and their water bodies are affected by a rapidly warming climate. lakes small ponds known to act as an important source of atmospheric methane. However, not much is about other types in permafrost regions, which include major rivers coastal bays transition type between freshwater marine environments. We monitored dissolved methane concentrations three different (Lena River, Tiksi Bay, Lake Golzovoye, Siberia, Russia) over period 2 years. Sampling was carried out...