George Bullerjahn

Dr. George Bullerjahn

Distinguished Research Professor
Ph. D., University of Virginia

Office:     516 Life Sciences Building
Phone:   1-419-372-8527

Research: Microbial physiology; Cyanobacteria   

Great Lakes Center for Fresh Waters and Human Health



Research Interests:

Our work is currently focused on enumeration and the physiological performance of phototrophs and ecologically important chemolithotrophs in aquatic systems. Additionally, we examine the composition and dynamics of cyanobacterial and nitrifying communities in freshwater environments, focusing primarily on the N and P cycles in the Laurentian Great Lakes.  These studies assist in the assessment of factors contributing to toxic cyanobacterial bloom events in freshwaters.

Selected Publications

Hampel, J., M.J. McCarthy, M. Neudeck, G.S. Bullerjahn, R.M. McKay and S.E. Newell. 2019. Ammonium recycling supports toxic Planktothrix blooms in Sandusky Bay, Lake Erie: evidence from stable isotope and metatranscriptome data.  Harmful Algae 81: 42-52.

Salk, K. R., G.S. Bullerjahn, R.M.L. McKay, J.D. Chaffin, and N.E. Ostrom. 2018. Nitrogen cycling in Sandusky Bay, Lake Erie: Oscillations between strong and weak export and implications for harmful algal blooms, Biogeosciences 15: 2891–2907.

Steffen, M.M., T.W. Davis, R.M. McKay, G.S. Bullerjahn, L.E. Krausfeldt, J.M.A. Stough, M.L. Neitzey, N.E. Gilbert, G.L. Boyer, T.H. Johengen, D.C. Gossiaux, A.M. Burtner, D. Palladino, M. Rowe, G.L. Dick, K. Meyer, S. Levy, B. Boone, R. Stumpf, T. Wynne, P.V. Zimba, D.B. Guttierez and S.W. Wilhelm. 2017. Ecophysiological examination of the Lake Erie Microcystis bloom in 2014: linkages between biology and the water supply shutdown of Toledo, Ohio. Environ. Sci. Technol. 51: 6745-6755. 

Bullerjahn, G.S., McKay, R.M.L., Davis, T.W., Baker, D.B., Boyer, G. L., D'Anglada, L.V., Doucette, G.J., Ho, J.C., Irwin, E.G., Kling, C.L., Kudela, R.M., Kurmayer, R., Michalak, A.M., Ortiz, J.D., Otten, T.G., Paerl, H.W., Qin, B., Sohngen, B.L., Stumpf, R.P., Visser, P.M. and Wilhelm, S.W. 2016. Global solutions for regional problems: collecting global expertise to address the problem of harmful algal blooms. - A Lake Erie case study. Harmful Algae 54C: 223-238.

Mukherjee, M.*, A. Ray*, A.F. Post, R.M. McKay and G.S. Bullerjahn. 2016.   Identification, enumeration and diversity of nitrifying planktonic archaea and bacteria in trophic end members of the Laurentian Great Lakes.  J. Great Lakes Res. 42: 39-49.

Davis, T.W., G.S. Bullerjahn, T. Tuttle*, M. Rozmarynowycz, R.M. McKay and S.B. Watson. 2015.  Evaluation of increasing nitrogen and phosphorus concentrations on the toxicity and chlorophyll content during cyanobacterial blooms in Sandusky Bay, Lake Erie.  Environ. Sci. Technol. 49: 7197-7207.

McKay, R.M.L., O. Prasil, L. Pechar, E. Lawrenz, M.L. Rozmarynowycz and G.S. Bullerjahn. 2015.  Freshwater ice as habitat: partitioning of phytoplankton and bacteria between ice and water in central European reservoirs.  Environmental Microbiology Reports 7: 887-898.

Davis, T., S.B. Watson, M.J. Rozmarynowycz, J.J.H. Ciborowski, R.M. McKay and G.S. Bullerjahn. 2014. Phylogenies of microcystin-producing cyanobacteria in the lower Laurentian Great Lakes suggest extensive genetic connectivity. PLOS ONE 9(9): e106093.

Wilhelm, S.W., G.L. LeCleir, G.S. Bullerjahn, R.M. McKay, M.A. Saxton, M.R. Twiss and R.A. Bourbonniere. 2014.  Seasonal changes in microbial community structure and activity imply winter production linked to summer hypoxia in a large lake system.  FEMS Microbiology Ecology 87: 475-485.

Steffen, M.M., Z. Zhu, R.M.L. McKay, S.W. Wilhelm and G.S. Bullerjahn. 2014.  Taxonomic assessment of a toxic cyanobacteria shift during the 2010 bloom in hypereutrophic Grand Lake St. Marys (Ohio, USA).  Harmful Algae 33: 12-18.

Bollmann, A., G.S. Bullerjahn and R.M. McKay. 2014.  Abundance and diversity of ammonia-oxidizing archaea and bacteria in sediments of trophic end members of the Laurentian Great Lakes, Erie and Superior.  PLOS ONE 9(5): e97068.

Kutovaya, O.A., R.M.L. McKay and G.S. Bullerjahn. 2013. Detection and expression of genes for phosphorus metabolism in picocyanobacteria from the Laurentian Great Lakes.  Journal of Great Lakes Research 39: 612-621.

Small, G.E., G.S. Bullerjahn, R.W. Sterner, B.F.N. Beall, S. Brovold, J.C. Finlay, R.M.L. McKay and M. Mukherjee. 2013.  Rates and controls on nitrification in a large oligotrophic lake.  Limnology and Oceanography 58: 276-286.

D’souza N.A., Y. Kawarasaki, J.D. Gantz, R.E. Lee, B.F.N. Beall, Y.M. Shtarkman, Z.A. Kocer, S.O. Rogers, H. Wildschutte, G.S. Bullerjahn and R.M.L.McKay. 2013. Diatom assemblages promote ice formation in large lakes.  ISME Journal 7: 1632-1640.

French, E., J. Kozlowski, M. Mukherjee, G. Bullerjahn and A. Bollmann. 2012.  Niche differentiation between ammonia-oxidizing archaea and bacteria based on differences in their growth responses to environmental factors.  Applied and Environmental Microbiology 78: 5773-5780.