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Microbial ecologist, biogeochemist, and astrobiologist studying the geochemistry and biology of methane cycling in water-rock hosted ecosystems.
My mission...
My mission...
I study water–rock–hosted ecosystems, particularly serpentinizing environments, where reactions between ultramafic rocks and water generate molecular hydrogen (H₂) that fuels life independent of sunlight. These systems provide natural laboratories for understanding how chemotrophic microorganisms—especially methanogens and methanotrophs—access energy, cycle carbon, and persist under extreme conditions such as high pH and low CO₂ availability.
My research connects microbial physiology and metabolism with geochemical energy landscapes to address questions relevant to both Earth and beyond. On Earth, serpentinizing systems are increasingly recognized for their potential roles in clean hydrogen production and carbon sequestration, yet we lack a clear understanding of how native microbial communities may enhance or hinder these processes through methane production, oxidation, and carbonate dissolution and precipitation. A central goal of my work is to quantify how microbial activity shapes—and is shaped by—these coupled carbon and hydrogen cycles.
These same processes are also relevant to astrobiology: H₂ detected in plumes from Saturn’s moon Enceladus could support life via the same microbial metabolisms observed in terrestrial serpentinizing systems. By integrating field observations, isotope tracer techniques, laboratory experiments, and ‘omics-based approaches, my research aims to build predictive models of microbial function across extreme environments, including hydrothermal systems. I am committed to engaging students directly in field and laboratory research, training them to link geologic processes with microbial activity through quantitative, interdisciplinary science.
Read the Nature Communications perspective on my scientific philosophy.
Current research
Methanogens - Calcium - Calcium Carbonates
Methanogens - Calcium - Calcium Carbonates
My research examines how methanogens operate in calcium-rich, CO₂-poor serpentinizing systems, where extreme chemistry shapes microbial metabolisms. In these settings, high calcium concentrations and elevated pH influence carbon availability and promote carbonate mineral formation, creating strong feedbacks between microbial activity and mineral precipitation. I investigate how methanogens adapt to these conditions and how their metabolism may influence carbonate formation and carbon sequestration. These microbe–mineral interactions have implications for Earth’s carbon cycle and for identifying potential biosignatures in ancient rocks and extraterrestrial environments.
Paper in prep, "Calcium influences methanogenesis in serpentinizing systems".
Figure: Schematic illustrating my hypothesis for methanogen carbonate mineral production. Look for my future paper by following my work (see links below)!
Methanogen Metabolic Networks - From Enzymes to Communities
Methanogen Metabolic Networks - From Enzymes to Communities
I investigate how methanogenic metabolism is structured across scales, from the molecular architecture of key enzymes to the organization of microbial communities in carbon-poor environments. A central focus is formylmethanofuran dehydrogenase (FMDH; Fwd/Fmd), the enzyme in the first step of CO₂-reducing methanogenesis, where differences in metal cofactors (W versus Mo) and substrate-access pathways may reflect adaptation to extreme pH and CO₂ scarcity. By linking enzyme structure and kinetics to physiological performance and community-level methane production, I aim to identify how metabolic constraints propagate upward to shape ecosystem function. This multi-scale perspective provides a framework for interpreting methane cycling on Earth and in planetary environments driven by water-rock reactions.
Relevant papers:
"Energetic and genomic potential for hydrogenotrophic, formaotrophic and acetoclastic methanogenesis in surface-expressed serpentinized fluids of the Samail Ophiolite" - the figure is a phylogenetic tree from this paper that shows a potentially novel group of Methanosarcinaceae methanogens associated with serpentinizing systems.
Methanotrophy at High pH
Methanotrophy at High pH
In hyperalkaline, serpentinizing systems, where reduced, H₂-rich (and CH₄-rich) fluids mix with more oxidized waters, microbial niches form. These environments host previously underexplored methanotrophs capable of oxidizing methane under alkaline pH, influencing methane flux and isotopic signatures. Through integrated field studies, microbial activity assays, and bulk and clumped methane isotope analyses, I plan to quantify how these organisms overprint primary methane sources and influence carbonate-forming pathways. This work refines methane-based life-detection strategies for ocean worlds and reveals how methanotrophy may contribute to carbon sequestration on Earth.
Paper in revision for Nature Communications, "Methanotrophy under extreme alkalinity in a serpentinizing system".
Figure: The core metabolism of a methanotroph detected in a system with pH > 11 (find the figure and read more in the linked preprint above).
Methanotrophy at High Temperature
Methanotrophy at High Temperature
My research pushes the known upper temperature limits of biological methane oxidation in continental hydrothermal systems. Using integrated geochemical measurements, sequencing surveys, and activity assays, I discovered that methane oxidation can persist at temperatures previously thought to preclude this metabolism. Evidence for active methane oxidation in the absence of known methanotrophic taxa suggests that uncharacterized thermophilic microorganisms are operating beyond established physiological boundaries. By linking methane oxidation rates to energy supply and substrate availability, this work reveals how extreme temperatures constrain—and sometimes enable—methanotrophy. These findings expand the recognized thermal niche of continental methane oxidation and inform interpretations of methane cycling in high-temperature environments on Earth.
Paper in revision, "Pushing the upper temperature limit of methanotrophy in continental hydrothermal ecosystems, active biological methane oxidation in hot springs of Yellowstone National Park".
Figure: Taxonomic classification of metagenome assembled genomes derived from a hydrocarbon-rich hot spring (89.9°C) where methane oxidation was detected, pushing the upper temperature limit of continental hydrothermal methane oxidation. No known methaotroph lineages were detected at this site, leaving room for discovery.
In the Media
My Current Research Assistants
Aspasia Vasquez
Aspasia Vasquez
Undergraduate at the University of Colorado, Boulder, pursuing a major in Evolutionary Biology and a minor in Geology. Aspasia is currently working toward completing an undergraduate thesis focused on the evolutionary ecology of FMDH.
Ashley Askins
Ashley Askins
A recent graduate of the Department of Geological Sciences at the University of Colorado, Boulder, Ashley is conducting physiological experiments on a methanogen isolated from serpentinized fluid to understand adaptations to low carbon and high pH conditions. She is hoping to attend graduate school in the fall.
Darya Patina
Darya Patina
Darya is an undergraduate pursuing a Bachelor's in Biological Sciences at Columbia University (NY). While she has a wealth of experience in cancer research, she joins us to learn more about astrobiology and to develop skills in genome sequencing, assembly, and annotation to discover novel adaptations to serpentinizing fluids.
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