Nagissa Mahmoudi

Department of Earth and Planetary Sciences

My research centers on the role that microorganisms play in regulating biogeochemical carbon cycling in aquatic environments. We are interested in addressing key questions regarding microbial controls on the transformation and remineralization rates of organic compounds, including natural organic matter (NOM) as well as anthropogenic contaminants. We use a highly interdisciplinary approach by coupling dual carbon isotope analysis along with experimental microbiology and molecular tools to gain new insights into the microbial interactions and metabolic pathways that underpin carbon cycling in marine environments.

Stern, R.A., Mahmoudi, N., Buckee, C.O., Schartup, A.T., Koutrakis, P., Ferguson, S.T., Wolfson, J.M., Wofsy, S.C., Daube, B.C., Sunderland, E.M., 2021. The Microbiome of Size-Fractionated Airborne Particles from the Sahara Region. Environmental Science and Technology 55(3), 1487-1496. 

LaRowe, D.E., Arndt, S., Bradley, J.A., Estes, E.R., Hoarfrost, A., Lang, S.Q., Lloyd, K.G., Mahmoudi, N., Orsi, W.D., Shah Walter, S.R., Steen, A.D., Zhao, R., 2020. The fate of organic carbon in marine sediments - New insights from recent data and analysis. Earth-Science Reviews 204, 103146. 

Mahmoudi, N., Enke, T.N., Beaupré, S.R., Teske, A.P., Cordero, O.X., Pearson, A., 2020. Illuminating microbial species-specific effects on organic matter remineralization in marine sediments. Environmental Microbiology 22(5), 1734-1747.

Mahmoudi, N., Hagen, S.M., Hazen, T.C., Steen, A.D., 2020. Patterns in extracellular enzyme activity and microbial diversity in deep-sea Mediterranean sediments. Deep-Sea Research Part I: Oceanographic Research Papers 158, 103231.

Miller, J.I., Techtmann, S., Joyner, D., Mahmoudi, N., Fortney, J., Fordyce, J.A., Garajayeva, N., Askerov, F.S., Cravid, C., Kuijper, M., Pelz, O., Hazen, T.C., 2020. Microbial communities across global marine basins show important compositional similarities by depth. mBio 11(4), e01448-20. 

Orcutt, B.N., Bradley, J.A., Brazelton, W.J., Estes, E.R., Goordial, J.M., Huber, J.A., Jones, R.M., Mahmoudi, N., Marlow, J.J., Murdock, S., Pachiadaki, M., 2020. Impacts of deep-sea mining on microbial ecosystem services. Limnology and Oceanography 65(7), 1489-1510.

Miller, J.I., Techtmann, S., Fortney, J., Mahmoudi, N., Joyner, D., Liu, J., Olesen, S., Alm, E., Fernandez, A., Gardinali, P., GaraJayeva, N., Askerov, F.S., Hazen, T.C., 2019. Oil hydrocarbon degradation by caspian sea microbial communities. Frontiers in Microbiology 10, 995. 

Mahmoudi, N., Beaupré, S.R., Steen, A.D., Pearson, A., 2017. Sequential bioavailability of sedimentary organic matter to heterotrophic bacteria. Environmental Microbiology 19(7), 2629-2644. 

Techtman, S.M., Mahmoudi, N., Whitt, K.T., Campa, M.F., Fortney, J.L., Joyner, D.C., Hazen, T.C., 2017. Comparison of Thaumarchaeotal populations from four deep sea basins. FEMS Microbiology Ecology 93(11), fix128.

Beaupré, S.R., Mahmoudi, N., Pearson, A., 2016. IsoCaRB: A novel bioreactor system to characterize the lability and natural carbon isotopic (14C, 13C) signatures of microbially respired organic matter. Limnology and Oceanography: Methods 14(10), 668-681. 

Hazen, T.C., Prince, R.C., Mahmoudi, N., 2016. Marine Oil Biodegradation. Environmental Science and Technology 50(5), 2121-2129. 

Brewer, S., Techtmann, S.M., Mahmoudi, N., Niang, D., Pfiffner, S., Hazen, T.C., 2015. Co-extraction of DNA and PLFA from soil samples. Journal of Microbiological Methods 115, 64-66. 

Mahmoudi, N., Robeson, M.S., II, Castro, H.F., Fortney, J.L., Techtmann, S.M., Joyner, D.C., Paradis, C.J., Pfiffner, S.M., Hazen, T.C., 2015. Microbial community composition and diversity in Caspian Sea sediments. FEMS Microbiology Ecology 91(1), 1-11. 

Mahmoudi, N., Porter, T.M., Zimmerman, A.R., Fulthorpe, R.R., Kasozi, G.N., Silliman, B.R., Slater, G.F., 2013. Rapid degradation of deepwater horizon spilled oil by indigenous microbial communities in louisiana saltmarsh sediments. Environmental Science and Technology 47(23), 13303-13312. 

Mahmoudi, N., Fulthorpe, R.R., Burns, L., Mancini, S., Slater, G.F., 2013. Assessing microbial carbon sources and potential PAH degradation using natural abundance 14C analysis. Environmental Pollution 175, 125-130.

Mahmoudi, N., Slater, G.F., Juhasz, A.L., 2013. Assessing limitations for PAH biodegradation in long-term contaminated soils using bioaccessibility assays. Water, Air, and Soil Pollution 224(2), 1411.

Mahmoudi, N., Slater, G.F., Fulthorpe, R.R., 2011. Comparison of commercial DNA extraction kits for isolation and purification of bacterial and eukaryotic DNA from PAH-contaminated soils. Canadian Journal of Microbiology 57(8), 623-628. 

Mahmoudi, N., Modanu, M., Brandt, Y., Andrade, M.C.B., 2008. Subtle pedipalp dimorphism: A reliable method for sexing juvenile spiders. Journal of Arachnology 36 (3), 513-517. 

McNichol, ​Samuel : Doctorat en sciences de la Terre et des planètes
Department of Earth and Planetary Sciences, McGill
Sujet de recherche : deep biosphere, carbon cycling
Sanger, Alia : Maîtrise en sciences de la Terre et des planètes
Department of Earth and Planetary Sciences, McGill
Sujet de recherche : marine microbiology, microbial evolution