Cluster of Excellence 'MicroPlanet'’s Post

📢 New paper in Nature Magazine 🚨 https://lnkd.in/d4xjPqNk Microbes rock 🎸🤘 with sulfide and iron minerals I am very excited to share our recent study, which describes a previously unknown microbial energy metabolism 🦠🧫⚡⚡⚡ 🆕 Microbial iron oxide respiration coupled to sulfide oxidation - briefly MISO Biogeochemical cycling is largely driven by microorganisms, yet sulfide oxidation by iron(III) oxide minerals - a critical step in the global sulfur and iron cycles in anoxic ecosystems - was considered to be a strictly chemical process. We now show that this redox reaction also powers 🔋🔌 a new chemolithoautotrophic lifestyle of anaerobic microbes 🦠🧫 Main findings ✅ The genetic capacity for sulfur compound oxidation and iron(III) oxide respiration co-occurs in genomes from 37 bacterial and archaeal phyla ✅ Desulfurivibrio alkaliphilus perfoms MISO - it grows autotrophically by oxidizing dissolved sulfide or iron monosulfide (FeS) to sulfate with ferrihydrite as electron acceptor ✅ MISO outperforms the chemical reaction under environmentally relevant sulfide concentrations ✅ Key MISO genes are evolutionarily conserved in the family Desulfurivibrionaceae and widely distributed across marine, freshwater, terrestrial, and engineered environments ✅ A first estimate indicates that MISO accounts for 1-7% of total sulfide oxidation in marine sediments on a global scale 🆕 These findings extend understanding of the interplay of sulfur and iron biogeochemistry in anoxic marine and terrestrial environments, providing a new biological mechanism for phenomena of sulfide detoxification and cryptic sulfate formation. 🙌 I am deeply thankful to songcan chen and Marc Mußmann, the other team members Nicola Battisti, Guoqing Guan, Maria A. Montoya, and great collaborators Xiao-Min Li, Jay Osvatic, Petra Pjevac, Shaul Pollak, Andreas Richter, Arno Schintlmeister, Wolfgang Wanek from our Centre for Microbiology and Environmental Systems Science and Cluster of Excellence 'MicroPlanet' for pulling this off💪 🙏 This work would not exist without support and funding from the Universität Wien and the Austrian Science Fund FWF #sulfide #ferrihydrite #sulfurcycle #ironcycle #ironoxide #microbiome

I am incredibly proud to share that my masters thesis, "Hypoxia Driven by Caribbean Sargassum Accumulation Events," has been published in Royal Society Open Science! 🌊🌱 Massive influxes of sargassum seaweed have been transforming Caribbean coastlines. Our research investigates a critical consequence of these events: the development of hypoxia (low-oxygen conditions) as the seaweed decomposes. Through incubation experiments and modeling, we show that low-oxygen conditions at night become more severe with increasing sargassum biomass. Furthermore, we found that less biomass is required to cause severe hypoxia in warmer waters with longer residence times. We hope the results of this study can be leveraged to develop early warning systems for similar events in the future. This work was a true team effort. A profound thank you to my amazing co-authors, Travis Courtney, Jenniffer Perez, Roy Armstrong, and JJ Cruz Mota. Your expertise, dedication, and support throughout this journey were indispensable. I am deeply grateful for your mentorship and collaboration. As these sargassum events become the new norm, understanding their environmental impact is crucial for proper coastal management and conservation. I hope our findings contribute meaningfully to the scientific dialogue and solutions for affected regions. The article is open access, so everyone can read our full findings: https://lnkd.in/eCXGqd4E #Sargassum #Caribbean #Hypoxia #ClimateChange #MarineBiology #Oceanography #CoastalScience #HarmfulAlgalBloom #Research #OpenScience #AcademicChatter #Masterslife #RoyalSociety

🌊🧫Oxygen Concentration and Its Implications for Microbial Structure and Metabolism: A Case Study in a Deep Tropical Reservoir by Alessandro Del’Duca et al. https://lnkd.in/dRPfGxnQ 1708 views The vertical stratification of oxygen concentration in deep reservoirs impacts nutrient cycling and ecosystem biodiversity. The Serra da Mesa reservoir, the largest in Brazil, was studied to evaluate the structure and production of the prokaryote community at five depths. Using 3H leucine incorporation and fluorescent in situ hybridization (FISH), the study focused on different depths near the dam, particularly within the euphotic zone. The water column was characterized into oxic, transitional, and hypoxic layers based on dissolved oxygen concentration. The highest densities and biomasses of prokaryotes were found at the euphotic zone’s depth limit, where bacterial production was low, suggesting inactive or slow-growing bacteria. #MicrobialEcology #ReservoirScience #OxygenDynamics #Biogeochemistry #TropicalEcosystems #ClimateChange

I recently completed two enriching weeks at the Max Planck Institute for Biogeochemistry, where I trained on determining microbial enzyme activity in soils using a microplate fluorimetric assay🧪 🌿Soil microbes secrete enzymes that drive C, N, P, and S cycles, powering plant nutrition, carbon sequestration, and ecosystem health. Measuring their activity helps us understand soil functional diversity and its role in climate-relevant processes. 🌍Hands-on insights gained: 🌱Preparations: Preparing buffers & substrates, autoclaving consumables. 🌱Buffers: MES buffer was essential to maintain a stable pH environment so that enzyme activity reflects true biological function. 🌱Substrates: I used MUF-linked substrates (e.g., MUF-phosphate, MUF-sulfate), which release a fluorescent signal upon cleavage by their target enzyme — a precise method for tracking activity. 🌱Procedures: ultrasonic disaggregation, pipetting into microplates, enzyme incubation, and fluorescence measurements. 🪴This experience helped me connect theory with practice — and contribute knowledge that directly supports the BioNecs project’s mission to link soil biochemistry, microbial ecology, and ecosystem sustainability. ☺️Grateful to the Max Planck team, especially Qing-Fang Bi and Marion Scrumpf, for their guidance and support 🙌 #SoilScience #MicrobialEcology #MaxPlanckInstitute #Biogeochemistry #Sustainability

A deep-sea hydrothermal vent worm detoxifies arsenic and sulfur by intracellular biomineralization of orpiment (As2S3) - PLOS Biology: The alvinellid worm Paralvinella hessleri is the only animal that colonizes the hottest part of deep-sea hydrothermal vents in the west pacific. We found P. hessleri accumulates exceptionally high level of toxic element arsenic (>1% of wet weight) and tolerated elevated concentrations hydrogen sulphide. Using advanced microscopy, elementary analysis, and genomics and proteomics approaches, we identified a previously unrecognized arsenic-sulfide biomineralization process in P. hessleri. Our data suggest that arsenic accumulates within epithelial cell granules, where it likely reacts with sulphide diffused inward from the hydrothermal vent fluid, resulting in the intracellular formation of orpiment (As₂S₃) minerals. In this "fighting poison with poison" manner, the highly toxic arsenic and sulphide were simultaneously detoxified in the form of orpiment minerals within the intracellular granules of the single layer of epithelial cells. This process represents a remarkable adaptation to extreme chemical environments. Our study provides new insights into understanding animals' environment adaptation mechanisms and the diversity and plasticity of biomineralization. https://lnkd.in/eus4zJGx

This work, that began with Christine Hatté nearly six years ago in a poster form at EGU, has finally ended and published in Global Change Biology. In addition to Christine Hatté, a warm thanks to all the authors : Sophie Cornu, Lauric Cecillon, Yannick Colin, Pierre Barré and Claire Chenu. The work required no funding, but time – a lot of time. Using two worldwide databases of 14C in soils, the idea was to consider the occurrence of SOC devoid of 14C (named ancient OC), which has been quantified both in concentration and in proportion to SOC in the top, sub and deepsoils. This ancient OC may have multiple origins, not only geological (or fossil, geogenic). The consequences are significant, as the 14C age of soils has been significantly rejuvenated, opening up new perspectives in the study of SOC dynamics. More in the paper https://lnkd.in/ermBY4pR

🚨 New Publication Alert 🚨 Excited to share our latest paper published in Soil Biology and Biochemistry: Planar optodes reveal spatiotemporal heterogeneity of oxic and pH microenvironments driven by dung beetle activity in soil 👉 https://lnkd.in/dUJVsywz Dung beetles are more than just recyclers of animal waste – they are powerful soil ecosystem engineers. Using a novel planar optode “soil sandwich” approach, we were able to visualize, in real-time and at sub-millimeter resolution, how the tunneling species Onthophagus nuchicornis reshapes soil chemistry. Key findings: - Beetle tunneling increased oxic–anoxic interfaces 8-fold, enhancing microbial habitat diversity. - Buried dung balls remained >75% anoxic for over 45 hours, confirmed via microsensor profiling. - Beetle activity raised local soil pH - Even under waterlogged, anoxic conditions, beetles continued to redistribute dung, tracked using fluorescent nanoparticles. These microscale dynamics highlight how dung beetles influence nutrient cycling, greenhouse gas emissions, and soil fertility – reinforcing their role as critical contributors to soil health and ecosystem functioning. Big thanks to my co-authors Gianluca Natta, Theresa Merl, Alex Laini, Angela Roggero, Antonio Rolando, Claudia Palestrini, Klaus Koren, and Ugo Marzocchi for an inspiring collaboration! Biology - Aarhus University; Faculty of Natural Sciences - Aarhus University #SoilScience #EcosystemServices #DungBeetles #Biogeochemistry #MicrobialEcology #SoilHealth #OpticalSensors

Digging deeper into root biomass and carbon quantification 🌱 During her PhD at Aarhus University, Nurbanu Shynggyskyzy developed a DNA-based ddPCR method to measure species-specific root biomass in mixed grassland communities – a breakthrough for understanding soil carbon storage and ecosystem resilience. Her research offers new tools for managing soil carbon stocks and tackling climate change. 📅 Public defence: Friday, 15 August 2025 at 13:30 📍 Auditorium, AU Flakkebjerg, Denmark Read more about the method and results in her PhD thesis: Development of a DNA-based ddPCR method for species-specific root biomass quantification and root C estimation - find the link in the comments below. #SoilScience #CarbonStorage #Agroecology #PhDDefence #SustainableAgriculture

Collaborators from NSLS-II worked with researchers to conduct X-ray bio-imaging experiments at the Submicron Resolution X-ray Spectroscopy and Life Science X-ray Scattering beamlines to study iron accumulation and cell wall structure in poplar plants. This helped the team gain a more complete understanding of PtrbHLH011, a plant protein that plays a key role in important biological processes in poplar plants and could pave the way for more robust crops in the future. #SynchrotronScience #StructuralBiology #PlantBiology #BeamlineScience #PlantScience #NSLSII #Plants

Calcified cyanobacteria from the Upper Ediacaran of South China - Frontiers in Marine Science: Fossil records of calcified cyanobacteria from the Neoproterozoic are rare despite the high carbonate saturation of contemporaneous seawater. In this study, we report the discovery of calcified cyanobacteria in microbialites from the Upper Ediacaran Dengying Formation in South China, based on integrated field investigations and petrographic analyses of polished surfaces and thin-sections. Scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD) reveal that filamentous sheath structures are preserved as dense, fine-crystalline dolomite. The tube-like microfossils are identified as the calcified cyanobacteria Girvanella. This discovery fills a gap in the fossil record of microbialite-hosted calcified cyanobacteria spanning the interval from the Cryogenian glaciations to the onset of the Cambrian Period. Petrographic and mineralogical analyses indicate that primary high-Mg calcite, precipitated in vivo within Girvanella sheaths as a likely precursor to microcrystalline dolomite, contributed to the exceptional preservation of these fossils. The sporadic occurrence of calcified cyanobacteria may reflect transient episodes of elevated carbonate saturation driven by fluctuations in seawater chemistry. Concurrently, the possible rapid evolution of CO2-concentration mechanisms (CCMs) may have enhanced the calcification capability of cyanobacteria. Thus, these features foreshadowed the widespread microbial calcification that emerged in the Cambrian.