Mary-Cathrine Leewis, Ph.D.

Image Mary-Cathrine Leewis
Research Scientist

Plant and Soil Microbiomes

Current research and/or projects

Dr. Leewis is a new scientist with AAFC and is developing a program of research focused the structure and function of microbial communities in soil, on the phyllosphere, and in the rhizosphere, particularly in arable cropping systems integrating the use of perennial forage species.

Research and/or project statements

  • Study the interrelationships between the soil microbiome and crops, and the potential effects of microbiomes on crop productivity.
  • Characterize soil and plant microbiomes to explore their function, and develop biotechnological applications based on fundamental knowledge.
  • Reduce, through the management of the plant microbiomes, the negative impact of agricultural on air and water quality while increasing production by improving the health of the agroecosystem according to a global health approach (One Health).

Education and awards

Ph.D. Biological Sciences (Microbial Ecology), University of Alaska Fairbanks, 2014

M.Sc. Biological Sciences, Northern Michigan University, 2006

B.Sc. Biology and French, Northern Michigan University, 2004

International experience and/or work

International Research Experience:

Collaborator & Invited Lecturer, University of Chemistry and Technology, Prague. Prague, Czech Republic. 2009 - Present


International Field Work Experience

2016 – 2020    Wilder Ranch State Park, California, USA.

2017                Harshaw Mining District, Arizona, USA.

2016, 2017      Alaska, USA. Permafrost tunnels and well drilling

2016                Gates of the Arctic National Park, Alaska, USA.

2014, 2015      Kevo Subarctic Research Station, Finland.

2012                Senegal, Cooperative Farms near Thies & Mbour

2008 – 2016    Bonanza Creek LTER, Alaska, USA.

2009                Svalbard Archipelago (Research cruise)

2006                Lakes of Northern Wisconsin, USA.

Key publications

Waldrop, M., McFarland, J., Manies, K., Leewis, M.C., Blazewicz, S., Jones, M., Neumann, R., Keller, J., Cohen, L., Euskirchen, E., Edgar, C., Turetsky, M., Cable, W. 2021. Carbon Fluxes and Microbial Activities from Boreal Peatlands Experiencing Permafrost Thaw. Journal of Geophysical Research: Biogeosciences. doi: 10.1029/2020JG005869.

Waldrop, M., Anderson, L., Clow, D., Erikson, L., Dornblaser, M., Gibbs, A., Herman-Mercer, N., James, S., Jones, M., Koch, J., Leewis, M.C., et al. 2021.  USGS Permafrost Research Determines the Risks of Permafrost Thaw to Biologic and Hydrologic Resources. USGS Publishing.

Leewis, M.C., Berlemont, R., Podgorski, D., Srinivas, A., Zito, P., Spencer, R., McFarland, J., Douglas, T., Conway, C., Waldrop, M., Mackelprang, R. 2020. Life at the frozen limit: Microbial Carbon Metabolism Across a Late Pleistocene Permafrost Chronosequence. Frontiers in Microbiology. 11: 1–15. doi: 10.3389/fmicb.2020.01753.

He, R., Su, Y., Leewis, M.C., Chu, Y., Yao, X., Ma, R., Herriott, I., Leigh, M.B. 2019. Low O2 level enhances CH4-derived carbon flow into microbial communities in landfill cover soils. Environmental Pollution. 113676.  doi: 10.1016/j.envpol.2019.113676

Brankovits, D., Pohlman, J, Niemann, H., Leigh, M. B., Leewis, M.C., Becker, K., Iliffe, T., Alvarez, F., Lehmann, M., Phillips, B. 2017. Methane- and dissolved organic carbon-fueled microbial loop supports a tropical subterranean estuary ecosystem. Nature Communications. 8: 1835. doi:10.1038/s41467-017-01776-x.

Martinez-Cruz, K., Leewis, M.C., Herriot, I., Sepulveda-Jauregui, A., Walter-Anthony, K., Thalasso, F., Leigh, M.B. 2017. Anaerobic oxidation of methane by aerobic methanotrophs in arctic lake sediments. Science of the Total Environment. 607-608. doi:10.1016/j.scitotenv.2017.06.187.

Meeboon, N., Leewis, M.C., Kaewsuwan, S., Maneerat, S., Leigh, M.B. 2017. Changes in bacterial diversity associated with bioremediation of used lubricating oil in tropical soils. Archives of Microbiology. doi:10.1007/s00203-017-1356-3.

Leewis, M.C.*, Uhlik, O.*, Fraraccio, S., McFarlin, K., Kottara, A., Glover, C., Macek, T., Leigh, M.B. 2016. Differential impacts of willow and mineral fertilizer on bacterial communities in diesel oil-polluted soil. Frontiers in Microbiology. 7:837. doi: 10.3389/fmicb.2016.00837.

Leewis, M.C., Uhlik, O., Leigh, M.B. 2016. Synergistic processing of biphenyl and benzoate: carbon flow through the bacterial community in polychlorinated biphenyl contaminated soil. Scientific Reports. 6:22145. doi:10.1038/srep22145.

Hernandez, R., Debenport, S., Leewis, M.C., Ndoye, F., Nkenmogne, I., Soumare, A., Thuita, M., Gueye, M., Miambi, E., Chapuis-Lardy, L., Diedhoiu, I., Dick, R. 2015. The native shrub, Piliostigma reticulatum as an ecological “resource island” for mango trees in the Sahel. Agriculture, Ecosystems & Environment. 204:51-61.

Leewis, M.C., Reynolds, C.M., Leigh, M.B. 2013. Long-term effects of nutrient addition and phytoremediation on diesel and crude oil contaminated soils in subarctic Alaska. Cold Regions Science and Technology. 96:129–137.

Uhlik, O., Leewis, M.C., Strejcek, M., Musilova, L., Leigh, M.B., Macek, T. 2013. Stable isotope probing in the metagenomics era: a bridge towards improved bioremediation. Biotechnology Advances.  31(2): 154-165.

Uhlik, O., Leewis, M.C., Kurzawova, V., Lovecka, P., Stursa, P., Demnerova, K., Mackova, M., Macek, T. “Chapter 4: Approaches to Microbial Diversity Analysis in Contaminated Environments” in Trends in Bioremediation and Phytoremediation. Chemosphere.  (Edited by Dr. G. Plaza).  2010. ISBN: 978-81-308-0424-8. 

Kleinheinz, G., Coenan, A., Zehms, T., Preedit, J., Leewis, M.C., McDermott, C. 2009. Effects of aquatic macrophytes on the survival of Escherichia coli in a laboratory microcosm.  Lake and Reservoir Management.  25:149-154. 

Kleinheinz, G., McDermott, C., Leewis, M.C., Englebert, E. 2006. Influence of sampling depth on Escherichia coli concentrations in beach monitoring.  Water Research.  40(20):3831-7.