Lab Members

Munakata-Marr Lab

Graduate Students

Olivia Salmon

oliviathumb Olivia is a master’s student in Dr. Munakata-Marr’s lab and is researching impacts of rare earth elements on the microbial communities of wastewater treatment systems. Olivia has a prior M.S. in Human Dimensions of Ecosystem Science and Management from Utah State University and has worked most recently in environmental consulting, with a focus on environmental assessments, subsurface investigations, landfill gas and groundwater monitoring, and regulatory permitting and compliance guidance for industrial facilities.

Sharp Lab

Postdoctoral Researchers

Kristin M. Mikkelson, Ph.D.

kristinthumb Kristin is a Research Associate in the Sharp lab with interests at the interface of environmental microbiology and hydrology. She received her bachelor’s in Environmental Engineering from Cornell University and her Ph.D. in Hydrology from the Colorado School of Mines. Kristin’s doctoral research investigated the affects of large-scale tree death on biogeochemical and hydrologic cycles. Her post-doctoral work shifted slightly and dove into the smaller-scale impacts of tree death on near-surface microbial processes. Her expertise also expanded during this tenure as she began investigating microbial processes in relation to nutrient cycling in engineered wetlands designed to treat impaired waters.

Graduate Students

Laura Leonard

laurathumb Laura is a a PhD student in the Sharp group with a B.S. and M.S. in Environmental Engineering from the Colorado School of Mines. Her research focuses on studying the impacts of mountain pine beetle infestation, specifically, the biogeochemical alterations associated with pine beetle induced tree mortality in Crested Butte, CO. By characterizing the soil gas flux, porewater, and microbial community shifts associated with pine needle decay, Laura hopes to determine the implications for forest recovery and nutrient export that could aid in the prediction for shifts in ecosystem function across montane watersheds.

Michael Vega

mikethumb Michael is a Hydrology PhD student working in the Sharp group. He completed his BS in geochemistry at Kansas State University, with a particular interest in metal cycling in groundwater. Michael focuses on nitrogen biogeochemistry in a wetland biofilm that treats eutrophic river water. Specifically, Michael is looking at how nitrogen bioremediation is coupled with other elemental cycles (i.e., carbon, metals), and how these combined cycles can promote microbial syntrophy.

Adam Brady

adamthumb Adam is a PhD student working in the Sharp group. He previously received his M.S. in Environmental Science and Engineering working with the Cath group at the Colorado School of Mines. An active duty Army officer, upon completion of his PhD Adam will return to the United States Military Academy as an Assistant Professor in the Department of Geography and Environmental Engineering. Adam is interested in constructed wetlands, water/wastewater/produced water treatment, life cycle analysis, and sustainability.

Spear Lab

Postdoctoral Researchers

Blake W. Stamps, Ph.D.

blakethumb Blake Stamps is a Sloan Postdoctoral Fellow at the Colorado School of Mines. He received his bachelor’s degree and Ph.D. from the University of Oklahoma in 2011 and 2016, both in Microbiology. His doctoral research investigated the role of bacteria and fungi in fouling and corrosion of fuel tanks storing a biodiesel blend used by the US Air Force. Since moving to the Colorado School of Mines, Dr. Stamps has explored the microbial community of the Orange County Water District Advanced Water Processing Facility and is currently focused on the risk of corrosion and biodeterioration caused by bacteria and fungi isolated from the International Space Station.

Graduate Students

Emily Kraus

emilythumb Emily is a Ph.D. student associated with the NASA Astrobiology Institute’s Rock-Powered Life group. For her dissertation, she is using field and lab work with ‘omics tools to characterize the metabolic capability, population dynamics, and identification of microbial life in the hyperalkaline fluids and solid rock of the serpentinizing subsurface in the Samail ophiolite of Oman. Emily also co-organized the first and second annual Rocky Mountain Geobiology Symposium (RMGS) in 2017/2018. and attended the International Geobiology Course in 2016. Prior to joining the GEM lab, Emily received her B.S. in Ecology and Evolutionary Biology from the University of Rochester and worked with with John Tarduno on magnetotactic bacteria magnetosomes.

Kalen Rasmussen

kalenthumb Kalen is currently a masters student in John Spear’s lab. He received his Bachelor’s degree in Chemical and Biochemical Engineering from Mines as well. He has worked on a variety of projects ranging from the impacts of rare earth elements on the microbial communities in wastewater treatment plants with Dr. Munakata-Marr to the microbiota of sour style beers. Kalen is currently funded through the Enda Bailey Sussman Foundation and the National Park Service, focusing on laminated, lithified, silica based hot springs in Yellowstone National Park. By exploring the living microbial communities, geochemical cycles, and lithified biomat associated with these hot springs I hope to link the lithified past with the living present.

Alex Honeyman

alexthumb Alex has worked part-time as a technician in the Spear Lab for two years, while filling his other hours as a Firefighter-EMT in the Rocky Mountains. Beginning Fall, 2018, Alex entered the Ph.D. program at the School of Mines with Dr. John Spear. Alex has been involved in a project assessing the microbial community structure of produced water (fracking) treatment systems and has also led a number of different projects: on microbial community composition of water-rock equilibrated communities in a mine, on the geographic dependence of fresh snowfall microbiology and chemistry leveraging remote sensing storm-track analyses, and on the role of microbe-soil dynamics in ecological response to high-severity forest fire burns in Colorado. Overall, Alex aims to synthesize high-throughput DNA sequencing / analysis techniques with remote sensing and big data.

Patrick Thieringer

patrickthumb Patrick is a Ph.D. student in John Spear’s lab with a BA in Geoscience from Skidmore College. His research interests include identifying the metabolic pathways that support microbial growth in the subsurface low temperature serpentinized environment, and the geochemistry significant in influencing these processes. Patrick is connected with the NASA Astrobiology Institute’s Rock Powered Life group, which has a field site researching the water-rock interactions and microbial life in the Samail Ophiolite in Oman. He is interested in combining techniques of genomic analysis with lipid extraction and analysis to better develop biomarker detection.



Linda Toberer

Lindathumb Linda is a volunteer in Dr. Spear’s lab and is fascinated by the wealth of biodiversity, complexity, interrelatedness of the world of the very small. She is researching microbes and fungi from a mine that has been deactivated for a hundred years. Her research focuses on identifying the organisms that thrive in an acidic environment for possible uses in acid mine drainage remediation. Linda has a bachelor’s degree in biology and was a physical therapist for 45 years. After retirement she went back to her old love of biology.

GEM Lab Alumni:

Christopher Trivedi, Ph.D.

christhumb Chris is a polar and geomicrobiologist with special interests in astro- and extreme microbiology. His graduate research focused on characterizing a low-temperature sulfidic spring system, Borup Fiord Pass, in the Canadian High Arctic. Borup is known as one of the best terrestrial analogs for studying conditions that might be present on the Jovian moon Europa. Chris’ work primarily uses genomic techniques to understand how microorganisms play a role in sulfur cycling under adverse conditions in such a cold environment. Chris’ postdoctoral work will transition to a more culture-centered research focus where he will be studying glacial algae and their impact on melt rates.

Zack Jones, Ph.D.

Tess Weathers, Ph.D.

Dina Drennan, Ph.D.

Stephanie Carr, Ph.D.