A5015166644- Methane Hydrates and Related Phenomena
- Microbial Community Ecology and Physiology
- Hydrocarbon exploration and reservoir analysis
- Marine and coastal ecosystems
- Metalloenzymes and iron-sulfur proteins
- Microbial Fuel Cells and Bioremediation
- Genomics and Phylogenetic Studies
- Marine Biology and Ecology Research
- CO2 Sequestration and Geologic Interactions
- Metal Extraction and Bioleaching
- Geochemistry and Elemental Analysis
- Geological Studies and Exploration
- Atmospheric and Environmental Gas Dynamics
- Geology and Paleoclimatology Research
- Hybrid Renewable Energy Systems
- Hydrogen Storage and Materials
- Wastewater Treatment and Nitrogen Removal
- Advanced X-ray and CT Imaging
- Protist diversity and phylogeny
- Ocean Acidification Effects and Responses
- Reservoir Engineering and Simulation Methods
- Hydraulic Fracturing and Reservoir Analysis
- Photosynthetic Processes and Mechanisms
- Paleontology and Stratigraphy of Fossils
- Drilling and Well Engineering
GEOMAR Helmholtz Centre for Ocean Research Kiel
2007-2025
Universität Hamburg
2012-2021
Faculty (United Kingdom)
2016
The effect of volcanic activity on submarine hydrothermal systems has been well documented along fast‐ and intermediate‐spreading centers but not from slow‐spreading ridges. Indeed, eruptions are expected to be rare axes. Here we report the presence venting associated with extremely fresh lava flows at an elevated, apparently magmatically robust segment center southern Mid‐Atlantic Ridge near 5°S. Three high‐temperature vent fields have recognized so far over a strike length less than 2 km...
The ultramafic-hosted Logatchev hydrothermal field (LHF) on the Mid-Atlantic Ridge is characterized by high hydrogen and methane contents in subseafloor, which support a specialized microbial community of phylogenetically diverse, hydrogen-oxidizing chemolithoautotrophs. We compared prokaryotic communities three sites located LHF encountered predominance archaeal sequences affiliated with methanogenic Methanococcales at all three. However, bacterial composition varied accordance differences...
Summary Lilliput was discovered in 2005 as the southernmost known hydrothermal field along Mid‐Atlantic Ridge. It is exceptional that it lacks high‐temperature venting probably because of a thickened crust. The absence thermophilic and hyperthermophilic prokaryotes emissions supports argument against presence hot subsurface at Lilliput, typically suggested for diffuse from areas venting. high phylogenetic diversity novelty bacteria observed could be low‐temperature influence, distinct...
Hydrothermal fluids passing through basaltic rocks along mid-ocean ridges are known to be enriched in sulfide, while those circulating ultramafic mantle typically elevated hydrogen. Therefore, it has been estimated that the maximum energy basalt-hosted systems is available sulfide oxidation and ultramafic-hosted hydrogen oxidation. Furthermore, thermodynamic models suggest greatest biomass potential arises from systems. We tested these predictions by measuring biological removal subsequent...
To assess the risk that mining of seafloor massive sulfides (SMS) from extinct hydrothermal vent environments has for changing ecosystem irreversibly, we sampled SMS analogous habitats Kairei and Pelagia fields along Indian Ridge. In total 19.8 million 16S rRNA tags 14 different sites were analyzed microbial communities compared with each other publicly available data sets marine environments. The chimneys appear to provide microorganisms are not found or only detectable in very low numbers...
Enhanced mineral dissolution in the benthic environment is currently discussed as a potential technique for ocean alkalinity enhancement (OAE) to reduce atmospheric CO 2 levels. This study explores how biogeochemical processes affect of alkaline minerals surface sediments during laboratory incubation experiments. These involved introducing dunite and calcite organic-rich from Baltic Sea under controlled conditions an oxic environment. The sediment cores were incubated with bottom water....
Abstract Anthropogenic carbon dioxide (CO 2 ) levels are rising to alarming concentrations in earth’s atmosphere, causing adverse effects and global climate changes. In the last century, innovative research on CO reduction using chemical, photochemical, electrochemical enzymatic approaches has been addressed. particular, natural conversion serves as a model for many processes extensive studies microbes enzymes regarding redox reactions involving have already conducted. this review we focus...
Abstract Carbon dioxide removal from the atmosphere and storage over long times scales in terrestrial marine reservoirs is urgently needed to limit global warming for sustainable management of carbon cycle. Ocean alkalinity enhancement by artificial addition carbonate minerals seafloor has been proposed as a method sequester atmospheric CO 2 store it ocean dissolved bicarbonate. Here, reaction-transport model used scrutinize efficacy calcite dissolution at well-studied site southwestern...
We present data on the co-registered geochemistry (in situ mass spectrometry) and microbiology (pyrosequencing of 16S rRNA genes; V1, V2, V3 regions) in five fluid samples from Irina II Logatchev hydrothermal field. Two were collected over 24 min same spot further three spatially distinct locations (20 cm, 3 m overlaying plume). Four low-temperature fluids are composed core bacterial community, namely specific Gammaproteobacteria Epsilonproteobacteria, which, however, differs relative...
Mixing processes of reduced hydrothermal fluids with oxygenated seawater and fluid-rock reactions contribute to the chemical signatures diffuse venting likely determine geochemical constraints on microbial life. We examined influence fluid chemistry diversity activity by sampling emanating through mussel beds at two contrasting vents. The H(2) concentration was very low basalt-hosted Clueless site, mixing models suggest O(2) availability throughout much habitat. In contrast, effluents from...
Seafloor massive sulfide (SMS) deposits form on the modern ocean seafloor at active hydrothermal vent systems through mixing of mineral-rich, fluids with ambient oxygenated seawater. Once activity ceases, seawater infiltrates these deposits, fostering to abiotic oxidative weathering. Microbial considerably accelerates this transformation, driving mineral breakdown, thus enhancing metal transport. Under conditions, restricting oxygen entrainment, low-oxygen zones below surface, shielding SMS...
The majority of the organic matter (OM) degradation on seafloor occurs in coastal regions. Since oxygen (O 2 ) becomes quickly depleted top sediments, most OM decomposition is driven by microbial sulfate reduction (SR) and fermentation, latter generating molecular hydrogen (H ). If H not consumed hydrogenotrophic microorganisms accumulates sedimentary porewaters, hindered. Despite importance scavenging for mineralization, knowledge oxidizers their constraints marine sediments still quite...
Summary This study examines the representativeness of low‐temperature hydrothermal fluid samples with respect to their chemical and microbiological characteristics. Within this scope, we investigated short‐term temporal microbial variability fluids. For purpose collected three consecutively from same spot at Clueless field near 5°S on southern Mid‐Atlantic Ridge over a period 50 min. During sampling, temperature was monitored online. We measured parameters, characterized community...
Although it has been more than 30 years since the discovery of deep-sea hydrothermal vents, comprehending interconnections between venting and microbial life remains a challenge. Here we investigate abiotic-biotic linkages in low-temperature biotopes at Desperate Lilliput on southern Mid-Atlantic Ridge. Both sites are basalt-hosted fluids exhibit expected chemical signatures. However, contrasting crustal permeabilities have proposed, supporting pervasive mixing but restricting circulation...
Sulfurimonas denitrificans was originally isolated from coastal marine sediments. It can grow with thiosulfate and nitrate or sulfide oxygen. Recently sequencing of its genome revealed that it encodes periplasmic cytoplasmic [NiFe]-hydrogenases but the role hydrogen for metabolism has remained unknown. We show first experimental evidence S. indeed express a functional uptake active hydrogenase on hydrogen. In fact, under provided conditions grew faster denser than alone even in absence...
ABSTRACT Sulfurimonas denitrificans is a sulfur-oxidizing epsilonproteobacterium. It has been reported to grow with sulfide and harbor genes that encode sulfide-quinone reductases (SQRs) (catalyze oxidation). However, the actual concentrations at which S. grows whether its SQRs are functional remain enigmatic. Here, we illustrate exhibits good growth, namely, 0.18 mM roughly 1.7 mM. Around 2.23 mM, appears inhibit growth. harbors three SQR homolog on genome (Suden_2082 for type II SQR,...
Thiomicrospira were originally characterized as sulfur-oxidizing chemolithoautotrophs. Attempts to grow them on hydrogen failed for many years. Only recently we demonstrated consumption among two of three tested and posited that may be more widespread than previously assumed. Here, investigate compare the ability presence group 1 [NiFe]-hydrogenase genes (enzyme catalyzes H2↔2H(+) + 2e(-)) sixteen different species. Seven these species encoded five could also consume hydrogen. All exhibiting...
Electrospinning, atomic layer deposition and then coating with enzyme extract yield an electrode, the hydrogen evolution activity of which is tunable.
Anthropogenic activities are modifying the oceanic environment rapidly and causing ocean warming deoxygenation, affecting biodiversity, productivity, biogeochemical cycling. In coastal sediments, anaerobic organic matter degradation essentially fuels production of hydrogen sulfide methane. The release these compounds from sediments is detrimental for (local) entails socio-economic consequences. Therefore, it vital to understand which microbes catalyze re-oxidation under environmental...