About the guests
Brandi Kiel Reese, PhD
Brandi Kiel Reese received a BS in Geology with a concentration in biogeochemistry from Southern Methodist University. She went on to complete her MS in Soil and Water Sciences at University of California, studying sulfur biogeochemistry of the Salton Sea, California. After completing her MS, she went on to complete her PhD in Oceanography at Texas A&M University, combining her background in geochemistry with molecular microbial ecology. Her current research is widely interdisciplinary, combining geology, biogeochemistry, and molecular microbiology to provide a more integrated examination of aquatic and sediment biogeochemical cycling. When examining various environments, she is guided by fundamental questions such as: Who is alive? What are they doing? What are the global implications of microbial life within Earth systems? Specifically, her lab specializes in combining state-of-the-art culture-independent molecular techniques (including metatranscriptomics and metagenomics) with high throughput culturing and advanced geochemical analysis to describe the total microbial environment. This systems biology approach to understanding microbial ecology has spanned marine and freshwater, shallow sediments within estuaries and coastal hypoxic zones, deeply buried continental mines and caves, and marine subsurface sediments through the International Ocean Discovery Program (IODP).
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Lydia Hayes-Guastelladf
Lydia Hayes-Guastella graduated with her BS in Microbiology from Michigan State University, working with microbial communities in ophiolite serpentinizing systems. She went on to obtain her MS in Marine Biology from Texas A&M University-Corpus Christi, where she studied nitrogen cycling in restored and natural wetlands influenced by wastewater treatment plants. Currently, she is working toward her PhD in Marine Science at University of South Alabama studying under her advisor Brandi Kiel Reese. She is investigating microbial communities in the extreme high pH environments of the serpentinite mud volcanoes of the Mariana Forearc, as well as the nutrient and energy limited deep subsurface sediments of the South Atlantic Gyre through culture independent methods including metagenomic and metatranscriptomic analysis, as well as culture dependent isolation and ecophysiological studies, looking at what is living there, how they are surviving, and what is their role in their environment. Her research interests are microbial communities’ survivability in extreme environments and how those communities relate to nutrient cycling dynamics.
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Episode notes
There are very few remaining locations on Earth that are untouched by humans, and those that do remain are in very extreme environments that are difficult to access. However, accessing and studying life in these extreme environments can provide unique insights to the biology of life. Understanding how simple organisms adapt and survive in seeming unlivable conditions is a unique field of study with the potential to inform and affect the human condition.
We’re joined in this episode by Dr. Brandi Kiel Reese and Lydia Hayes-Guastella from the Dauphin Island Sea Lab at the University of South Alabama. They are both geomicrobiologists that study microbial life in extreme environments like the Mariana Trench and Antarctica. They do an excellent job of painting a picture of how extreme conditions are in these environments and how they manage to collect and preserve samples from such harsh conditions. We learn about the various methods they use to analyze the microbial samples they collect, including the use of digital PCR (dPCR) to detect and quantify transcripts that would otherwise not be detectable given how few cells they’re able to collect.
Brandi and Lydia also share their unpredictable career path journeys, while sharing some insights and learnings from their respective experiences. We learn what they each love about their work and what qualities it takes to be successful at what they do. Once again, we’re reminded of what a small world it is, especially when you’re in a specialty field such as geomicrobiology of extreme environments.
Affiliation links
Brandi Kiel Reese
Lydia Hayes-Guastella
Publications
Brandi Kiel Reese
- Kiel Reese, B., Sobol, M. S., Bowles, M. W., & Hinrichs, K.-U. (2021). Redefining the Subsurface Biosphere: Characterization of Fungi Isolated From Energy-Limited Marine Deep Subsurface Sediment. Frontiers in Fungal Biology, 2. https://doi.org/10.3389/ffunb.2021.727543
- Kiel Reese, B., Zinke, L. A., Sobol, M. S., LaRowe, D. E., Orcutt, B. N., Zhang, X., Jaekel, U., Wang, F., Dittmar, T., Defforey, D., Tully, B., Paytan, A., Sylvan, J. B., Amend, J. P., Edwards, K. J., & Girguis, P. (2018). Nitrogen Cycling of Active Bacteria within Oligotrophic Sediment of the Mid-Atlantic Ridge Flank. Geomicrobiology Journal, 35(6), 468–483. https://doi.org/10.1080/01490451.2017.1392649
- Mullis, M. M., Selwyn, J. D., Kevorkian, R., Tague, E. D., Castro, H. F., Campagna, S. R., Lloyd, K. G., & Kiel Reese, B. (2023). Microbial survival mechanisms within serpentinizing Mariana forearc sediments. FEMS Microbiology Ecology, fiad003. https://doi.org/10.1093/femsec/fiad003
Lydia Hayes-Guastella
- Hayes, L. (2020). Assessment and Valuation of Nitrogen Mitigation Ecosystem Services in Natural and Restored Wetlands of the Texas Coastal Bend (Masters Thesis, Texas A&M University-Corpus Christi).