Biology & Marine Biology

Faculty & Staff

Tolar_headshot.jpegBradley Tolar, Assistant Professor

Ph.D., Microbiology, University of Georgia, Athens, GA, 2014
B.S., Microbiology, Louisiana State University, Baton Rouge, LA, 2008
CMS 2331 |(910) 962-7302
5600 Marvin K. Moss Ln, Wilmington, NC 28409 |

 Research Interests:

Microorganisms drive global elemental cycles and are crucial for ecosystem function. My research investigates relationships between biogeochemically-important microbes and their environment to establish a baseline of seasonal change and stress tolerance. Though I am interested in many Bacteria and Archaea, my focus is on Thaumarchaeotaammonia-oxidizing Archaea that transform fixed nitrogen (ammonia) to nitrite, connecting oxidized and reduced forms of bioavailable nitrogen. Thaumarchaeota are abundant and broadly distributed across Earth, inhabiting both terrestrial and aquatic as well as high- and low-temperature systems. As a microbiologist trained in oceanography and earth systems, I use a systems-level perspective to study one of the most abundant organisms on the planet, synthesizing field- and lab-based research empowered by bioinformatics. I am particularly interested in investigating thaumarchaeal responses to disturbances and changing environments, focusing on how specific ecotypes (“species”) are impacted. Current and past research sites include the Gulf of Mexico, estuaries along the coastal Atlantic Ocean, Monterey Bay, the Southern Ocean, and floodplains in Wyoming and Colorado.

Select publications:

  1. Tolar, B.B., K. Boye, C. Bobb, K. Maher, J.R. Bargar, and C.A. Francis. Stability of floodplain subsurface microbial communities through seasonal hydrological and geochemical cycles (2020). Front Earth Sci. 8: 338.

    Reji, L., B.B. Tolar, F.P. Chavez, and C.A. Francis. Depth-differentiation and seasonality of planktonic microbial assemblages in the Monterey Bay upwelling system (2020). Front Aquat Microbiol. 11:1075. *Aquatic Microbiology Editor’s Pick 2021

    Tolar, B.B., L. Reji, J.M. Smith, M. Blum, J.T. Pennington, F.P. Chavez, and C.A. Francis. Time series assessment of Thaumarchaeota ecotypes in Monterey Bay reveals the importance of water column position in predicting distribution-environment relationships (2020). Limnol Oceanogr. 65: 2041-2055.

    Tolar, B.B., A.C. Mosier, M.B. Lund, and C.A. Francis. Nitrosarchaeum (gbm01289). In: Bergey’s Manual of Systematics of Archaea and Bacteria, Ed: W.B. Whitman, John Wiley & Sons: Hoboken, NJ (2019).

    Damashek, J., C.F. Edwardson, B.B. Tolar, S.M. Gifford, M.A. Moran, and J.T. Hollibaugh. Coastal ocean metagenomes and curated metagenome-assembled genomes (MAGs) from Marsh Landing, Sapelo Island (Georgia, USA) (2019). Microbiol Resour Announc 8: e00934-19.

    Reji, L. B.B. Tolar, J.M. Smith, F.P. Chavez, and C.A. Francis. Depth distributions of nitrite reductase (nirK) gene variants reveal spatial dynamics of thaumarchaeal ecotype populations in coastal Monterey Bay (2019). Environ Microbiol 21: 4032-4045.

    Damashek, J., B.B. Tolar, Q. Liu, A.O. Okotie-Oyekan, N.J. Wallsgrove, B.N. Popp, and J.T. Hollibaugh. Microbial oxidation of nitrogen supplied as selected organic nitrogen compounds in the South Atlantic Bight (2019). Limnol Oceanogr 64: 982-995.

    Reji, L., B. B. Tolar, J.M. Smith, F.P. Chavez, and C.A. Francis. Differential co-occurrence relationships shaping ecotype diversification within Thaumarchaeota populations in the coastal ocean water column (2019). ISME J 13: 1144-1158.

    Li, P-N., J.R. Herrmann, F.P.B. Poitevin, R. Ramdasi, B.B. Tolar, J. Bargar, D. Stahl, G. Jensen, S. Wakatsuki, and H. van den Bedem. Cryo electron tomography and reaction-diffusion simulations reveal a molecular and evolutionary basis for charged archaeal surface layer proteins (2018). Biophys J 114: 495A.

    Li, P-N., J. Herrmann, B.B. Tolar, F. Poitevin, R. Ramdasi, J.R. Bargar, D.A. Stahl, G.J. Jensen, C.A. Francis, S. Wakatsuki, and H. van den Bedem. Nutrient transport suggests an evolutionary basis for charged archaeal surface layer proteins (2018).  ISME J 12: 2389-2402.

    Liu, Q., B.B. Tolar, M.J. Ross, J.B. Cheek, C.M. Sweeney, N.J. Wallsgrove, B.N. Popp, and J.T. Hollibaugh. Light and temperature control the seasonal distribution thaumarchaeota in the South Atlantic Bight (2018). ISME J 12: 1473-1485.

    Tolar, B.B., N.J. Wallsgrove, B.N. Popp, and J.T. Hollibaugh. Oxidation of urea nitrogen in Thaumarchaeota-dominated marine nitrifying communities (2017). Environ Microbiol 19: 4838-4850.

    Tolar, B.B., J. Herrmann, J.R. Bargar, H. van den Bedem, S. Wakatsuki, and C.A. Francis. Integrated structural biology and molecular ecology of N-cycling enzymes from ammonia-oxidizing Archaea (2017).  Environ Microbiol Reports 9: 484-491.

    Kremer, C.T., A.K. Williams, M. Finiguerra, A.A. Fong, A. Kellerman, S.F. Paver, B.B. Tolar, and B.J. Toscano. Realizing the potential of trait-based aquatic ecology: new tools and collaborative approaches (2017). Limnol Oceanogr 62: 253-271.

    Tolar, B.B., L.C. Powers, W.M. Miller, N.J. Wallsgrove, B.N. Popp, and J.T. Hollibaugh. Ammonia oxidation in the ocean is inhibited by hydrogen peroxide (2016). Front Mar Sci 3: 237.

    Hundey, E.J., J.H. Olker, C. Carriera, R.M. Daigle, A.K. Elgin, M. Finiguerra, N.J. Gownaris, N. Hayes, L. Heffner, N.R. Razavi, P.D. Shirey, B.B. Tolar, and E.M. Wood-Charlson. A shifting tide: Recommendations for incorporating science communication into graduate training (2016). Limnol Oceanogr Bulletin 25: 109-116.

    Tolar, B.B., M.J. Ross, N.J. Wallsgrove, Q. Liu, L.I. Aluwihare, B.N. Popp, and J.T. Hollibaugh. Significant rates of chemoautotrophy in Antarctic coastal waters attributed to ammonia oxidation by Thaumarchaeota (2016). ISME J 10: 2605-2619.

    Liu, Q., X. Lu, B.B. Tolar, X. Mou, and J.T. Hollibaugh. Concentrations, turnover rates and fluxes of polyamines in coastal waters of the South Atlantic Bight (2015). Biogeochemistry 123: 117-133.

    Luo, H., B.B. Tolar, B.K. Swan, C.L. Zhang, R. Stepanauskas, M.A. Moran, and J.T. Hollibaugh. Single cell genomes of marine thaumarchaeota reveal insights into population differentiation by depth (2014). ISME J 8: 732-736.

    Hollibaugh, J.T., S.M. Gifford, M.A. Moran, M. Ross, S. Sharma, and B.B. Tolar. Seasonal variation in the metatranscriptomes of a Thaumarchaeota population from SE USA coastal waters (2014). ISME J 8: 685-698.

    Smith, C.B., B.B. Tolar, J.T. Hollibaugh, and G.M. King. Alkane hydroxylase gene (alkB) phylotype composition and diversity in northern Gulf of Mexico bacterioplankton (2013). Front Aquat Microbiol 4: 370.

    Tolar, B.B., G.M. King, and J.T. Hollibaugh. An analysis of Thaumarchaeota populations from the northern Gulf of Mexico (2013). Front Aquat Microbiol 4: 72.

    King, G.M., C. Smith, B. Tolar, and J.T. Hollibaugh. Analysis of composition and structure of coastal to mesopelagic bacterioplankton communities in the northern Gulf of Mexico (2013). Front Microbiol 3: 438.