Current Research

I am fascinated by extremophiles and their ability to survive in some of the harshest conditions on Earth. The goal of my current research is to use microscopy and molecular biology techniques to probe these exotic microorganisms in order to understand their activity and involvement in biogeochemical cycling within their environmental context. I hope to derive fundamental rules governing microbial metabolisms and habitability to reveal the potential for life elsewhere in our solar system and utility for industrial applications.

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Mid-Cayman Rise

The Mid-Cayman Rise in the Caribbean Sea is home to two known vent fields: Beebe and Von Damm. At nearly 5 km beneath the surface, Beebe is the deepest hydrothermal system currently known. Its fluids are extremely hot, acidic and rich in sulfide, metals, and hydrogen gas. In contrast, Von Damm is cooler, more alkaline, and methane- and hydrogen-rich. While the fluids have been well characterized, little is known about the solid chimneys and the microbial communities they host. Currently, I'm using a combination of sequencing and microscopy techniques to understand the microbial community composition and their spatial distribution within and across different vents.

The Cedars

Situated in Sonoma County in northern California, The Cedars formed where part of the subducting oceanic plate had been scraped on to the converging continental plate. This material would have been rich in ultramafic rock that could react with water in a process known as serpentinization, creating environments analogous to ones we may find on Mars or ocean words like Enceladus. Serpentinized fluid percolates back to the surface, creating ultrabasic pools encrusted in carbonates. Currently, only a few of these pools have been well studied, so I'm looking to discover and characterize new springs at The Cedars and use these pools to understand microbial colonization on mineral surfaces.

Past Projects

Organism-level metabolic rates

Compiled the largest database of organismal-level metabolic rates to date in tandem with quantifying energy fluxes and biomass-energy relations at the global biosphere level with coauthors.

Relevant publications:

Hoehler, T., Mankel, D., Girguis, P., McCollom, T., Kiang, N., Jørgensen, B. B. (2023) The metabolic rate of the biosphere and its components. Proc. Natl. Acad. Sci. U.S.A. 120(25): e2303764120. https://doi.org/10.1073/pnas.2303764120

Lost City Hydrothermal FIeld

Cultured some of the first microbial from the LCHF consortia and developed geochemical simulations of experiments in Crunchflow

MSU Observatory

Operated the 1-meter telescope and collected photometry from exoplanet candidates, variables stars, and microlensing events and submitted data to AAVSO and CBA databases

Relevant publications:

Murphy-Glaysher, F. J., ... , Mankel, D., et al. (2022). V392Persei: A γ-ray bright nova eruption from a known dwarf nova, Monthly Notices of the Royal Astronomical Society, 514 (4), 6183–6202. https://doi.org/10.1093/mnras/stac1577.
Patterson, J., de Miguel, E., ... , Mankel, D., et al. (2017). OV Bootis: Forty Nights Of World-Wide Photometry. Society for Astronomical Sciences, 1-6.

Shewanella Engineering

Isolated NADH dehydrogenase mutants of S. oneidensis and cloned mutants with constitutively expressed fluorescent proteins.