After graduating from high school (Gymnasium) in Bammental, Germany, I completed my undergraduate degree in Geoecology at the University of Tuebingen. I then moved to Tempe, Arizona, for my Ph.D. in Environmental Life Sciences at Arizona State University before joining Stanford as a postdoc.

Honors & Awards

  • NASA Postdoctoral Program (NPP) Fellowship, NASA (2021-2024)
  • USAID Global Development Research scholarship, USAID (2017-2018)
  • APS/NAI Lewis & Clark Fund for Exploration and Field Research in Astrobiology, American Philosophical Society (2017)
  • ASU’s Graduate and Professional Association Outstanding Mentor Award, Arizona State University (2016)
  • NASA (NAI) Astrobiology Early Career Collaboration Award, NASA (2016)
  • DAAD (German Research Exchange Service) Doctoral fellowship, German Research Exchange Service (2014-2015)

Stanford Advisors

Current Research and Scholarly Interests

Earth has transitioned from an abiotic planet to a vibrant biosphere over billions of years. During the first half of this transition, all living entities were prokaryotic microorganisms centralized in marine ecosystems. The interplay of non-living matter and microorganisms played a key role in metabolic evolution. I envision the major biogeochemical cycles (C, N, S) as “mosaics” of enzymatic and non-enzymatic reactions that co-evolved on a transitioning planet. To understand the modern biosphere, we must learn more about its origin and how it came to be.

My research interests revolve around the co-evolution of microbial life and Earth processes, the relation of these to the planetary climate, as well as astrobiology. I combine fieldwork and in-situ experiments with laboratory analyses and apply cutting-edge geochemical and molecular biological techniques, including isotopic tracers, DNA and RNA analysis, gene tree/species tree reconciliation and ancestral character state reconstruction, fluorescence in-situ hybridization (FISH), and microbiological culturing. I am also familiar with lipid analysis and nanoscale secondary ion mass spectrometry (nanoSIMS).

In the spirit of the Stanford Doerr School of Sustainability, I am also passionate about seeking solutions for global climate change by focusing on greenhouse gas removal from the atmosphere. I see high potential in the carbon dioxide, methane, and nitrous oxide consumption by enhanced mineral-microbial catalysis – processes that have been controlling gas fluxes since billions of years.

Lab Affiliations

All Publications

  • Mineral-catalysed formation of marine NO and N2O on the anoxic early Earth NATURE GEOSCIENCE Buessecker, S., Imanaka, H., Ely, T., Hu, R., Romaniello, S. J., Cadillo-Quiroz, H. 2022; 15 (12): 1056-+
  • Coupled abiotic-biotic cycling of nitrous oxide in tropical peatlands. Nature ecology & evolution Buessecker, S., Sarno, A. F., Reynolds, M. C., Chavan, R., Park, J., Fontanez Ortiz, M., Perez-Castillo, A. G., Panduro Pisco, G., Urquiza-Munoz, J. D., Reis, L. P., Ferreira-Ferreira, J., Furtunato Maia, J. M., Holbert, K. E., Penton, C. R., Hall, S. J., Gandhi, H., Boechat, I. G., Gucker, B., Ostrom, N. E., Cadillo-Quiroz, H. 2022


    Atmospheric nitrous oxide (N2O) is a potent greenhouse gas thought to be mainly derived from microbial metabolism as part of the denitrification pathway. Here we report that in unexplored peat soils of Central and South America, N2O production can be driven by abiotic reactions (≤98%) highly competitive to their enzymatic counterparts. Extracted soil iron positively correlated with in situ abiotic N2O production determined by isotopic tracers. Moreover, we found that microbial N2O reduction accompanied abiotic production, essentially closing a coupled abiotic-biotic N2O cycle. Anaerobic N2O consumption occurred ubiquitously (pH 6.4-3.7), with proportions of diverse clade II N2O reducers increasing with consumption rates. Our findings show that denitrification in tropical peat soils is not a purely biological process but rather a 'mosaic' of abiotic and biotic reduction reactions. We predict that hydrological and temperature fluctuations differentially affect abiotic and biotic drivers and further contribute to the high N2O flux variation in the region.

    View details for DOI 10.1038/s41559-022-01892-y

    View details for PubMedID 36202923

  • An essential role for tungsten in the ecology and evolution of a previously uncultivated lineage of anaerobic, thermophilic Archaea. Nature communications Buessecker, S., Palmer, M., Lai, D., Dimapilis, J., Mayali, X., Mosier, D., Jiao, J., Colman, D. R., Keller, L. M., St John, E., Miranda, M., Gonzalez, C., Gonzalez, L., Sam, C., Villa, C., Zhuo, M., Bodman, N., Robles, F., Boyd, E. S., Cox, A. D., St Clair, B., Hua, Z., Li, W., Reysenbach, A., Stott, M. B., Weber, P. K., Pett-Ridge, J., Dekas, A. E., Hedlund, B. P., Dodsworth, J. A. 2022; 13 (1): 3773


    Trace metals have been an important ingredient for life throughout Earth's history. Here, we describe the genome-guided cultivation of a member of the elusive archaeal lineage Caldarchaeales (syn. Aigarchaeota), Wolframiiraptor gerlachensis, and its growth dependence on tungsten. A metagenome-assembled genome (MAG) of W. gerlachensis encodes putative tungsten membrane transport systems, as well as pathways for anaerobic oxidation of sugars probably mediated by tungsten-dependent ferredoxin oxidoreductases that are expressed during growth. Catalyzed reporter deposition-fluorescence in-situ hybridization (CARD-FISH) and nanoscale secondary ion mass spectrometry (nanoSIMS) show that W. gerlachensis preferentially assimilates xylose. Phylogenetic analyses of 78 high-quality Wolframiiraptoraceae MAGs from terrestrial and marine hydrothermal systems suggest that tungsten-associated enzymes were present in the last common ancestor of extant Wolframiiraptoraceae. Our observations imply a crucial role for tungsten-dependent metabolism in the origin and evolution of this lineage, and hint at a relic metabolic dependence on this trace metal in early anaerobic thermophiles.

    View details for DOI 10.1038/s41467-022-31452-8

    View details for PubMedID 35773279