Dr. Katharina Besemer


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Research Interest

I believe that understanding freshwater systems is vital to protect freshwater ecosystems and preserve our most important resource - clean water. I am fascinated by the microbes that inhabit freshwater ecosystems because in spite of their small size, microbes greatly contribute to ecosystem functions and even to global biochemical cycles. Especially microbial biofilms, the ensemble of autotrophic and heterotrophic microorganisms that grow at the sediment-water interface of streams and rivers, play a key role in the self-purification processes of streams and rivers.

My research focuses on the structure and function of microbial communities in streams and rivers. Microbes are the most abundant and diverse organisms on earth and I am particularly interested in the distribution of this huge biodiversity in landscapes ranging from millimetres to kilometres. I apply next-generation sequencing technologies to characterize microbial communities and interpret the data within the framework of ecological theory. Understanding the interactions of biofilm microorganisms with their environment is crucial to predict the functioning of aquatic ecosystems in the context of global change.


• T.J. Battin, K. Besemer, M. Bengtsson, A. Romaní, A. Packmann (2016). The ecology and biogeochemistry of stream biofilms. Nat. Rev. Microbiol. 14: 251-263

• K. Besemer (2016). Microbial Biodiversity in Natural Biofilms. In: A.M. Romaní, H. Guasch, M.D. Balaguer (eds.) Aquatic Biofilms: Ecology, Water Quality and Wastewater Treatment. Caister Academic Press, Norfolk, p. 63-87.

• K. Besemer (2015). Biodiversity, community structure and function of biofilms in stream ecosystems. Res. Microbiol. 166: 774-781

• K. Wagner, K. Besemer, N.R. Burns, T.J. Battin, M.M. Bengtsson (2015). Light availability affects stream biofilm bacterial community composition and function, but not diversity. Environ. Microbiol. 17: 5036-5047

• L. Wilhelm, K. Besemer, L. Fragner, H. Peter, W. Weckwerth, T.J. Battin (2015). Altitudinal patterns of diversity and functional traits of metabolically active microorganisms in stream biofilms. ISME J. 9: 2454-2464

• S. Widder, K. Besemer, G. Singer, S. Ceola, E. Bertuzzo, C. Quince, W.T. Sloan, A. Rinaldo, T.J. Battin (2014). Fluvial network organisation imprints on microbial co-occurrence networks. Proc. Nat. Acad. Sci. 111: 12799-12804

• K. Wagner, M. Bengtsson, K. Besemer, A. Sieczko, N. Burns, E. Herberg, T.J. Battin (2014). Functional and structural responses of hyporheic biofilms to varying sources of dissolved organic matter. Appl. Environ. Microbiol. 80: 6004-6012

• L. Wilhelm, K. Besemer, C. Fasching, G.A. Singer, C. Quince, T. Urich, T.J. Battin (2014). Rare but active taxa contribute to community dynamics of benthic biofilms in glacier-fed streams. Environ. Microbiol. 16: 2514-2524

• I. Hödl, L. Mari, E. Bertuzzo, S. Suweis, K. Besemer, A. Rinaldo, T.J. Battin (2014). Biophysical controls on cluster dynamics and architectural differentiation of microbial biofilms in contrasting flow environments. Environ. Microbiol. 16: 802-812

• K. Besemer, G.A. Singer, C. Quince, E. Bertuzzo, W.T. Sloan, T.J. Battin (2013). Headwaters are critical reservoirs of microbial diversity for fluvial networks. Proc. R. Soc. Lond., Ser. B 280: 20131760

• L. Wilhelm, G.A. Singer, C. Fasching, T.J. Battin, K. Besemer (2013). Microbial biodiversity in glacier-fed streams. ISME J. 7: 1651-1660

• S. Woodcock, K. Besemer, T.J. Battin, T.P. Curtis, W.T. Sloan (2013). Modelling the effects of dispersal mechanisms and hydrodynamic regimes upon the structure of microbial communities within fluvial biofilms. Environ. Microbiol. 15: 1216-1225

• K. Besemer, H. Peter, J.B. Logue, S. Langenheder, E.S. Lindström, L.J. Tranvik, T.J. Battin (2012). Unraveling assembly of stream biofilm communities. ISME J. 6: 1459-1468

• E.K. Hall, K. Besemer, L. Kohl, C. Preiler, K. Riedel, T. Schneider, W. Wanek, T.J. Battin (2012). Effects of resource chemistry on the composition and function of hyporheic stream biofilms. Front. Microbiol. 3: 35.

• I. Hödl, J. Hödl, A. Wörman, G. Singer, K. Besemer, T.J. Battin (2011). Voronoi tessellation captures very early clustering of single primary cells as induced by interactions in nascent biofilms. PLoS ONE 6: e26368.

• G. Singer, K. Besemer, G. Hochedlinger, A.-K. Chlup, T.J. Battin (2011). Monomeric carbohydrate uptake and structure-function coupling in stream biofilms. Aquat. Microb. Ecol. 62: 71-83.

• G. Singer, K. Besemer, P. Schmitt-Kopplin, I. Hödl, T.J. Battin (2010). Physical heterogeneity increases biofilm resource use and its molecular diversity in stream mesocosms. PLoS ONE 5: e9988.

• K. Besemer, G. Singer, I. Hödl, T.J. Battin (2009). Bacterial community composition of stream biofilms in spatially variable flow environments. Appl. Environ. Microbiol. 75: 7189-7195

• K. Besemer, I. Hödl, G. Singer, T.J. Battin (2009). Architectural differentiation reflects bacterial community structure in stream biofilms. ISME J. 3: 1318-1324

• K. Besemer, B. Luef, S. Preiner, B. Eichberger, M. Agis, P. Peduzzi (2009). Sources and composition of organic matter for bacterial growth in a large European river-floodplain system (Danube, Austria). Org. Geochem. 40: 321-331.

• K. Besemer, G. Singer, R. Limberger, A.-K. Chlup, G. Hochedlinger, I. Hödl, C. Baranyi, T.J. Battin (2007). Biophysical controls on community succession in stream biofilms. Appl. Environ. Microbiol. 73: 4966-4974.

• G. Singer, K. Besemer, I. Hödl, A.-K. Chlup, G. Hochedlinger, P. Stadler, T.J. Battin (2006). Microcosm design and evaluation to study stream microbial biofilms. Limnol. Oceanogr. Methods 4: 436-447

• K. Besemer, M.M. Moeseneder, J.M. Arrieta, G. Herndl, P. Peduzzi (2005). Complexity of bacterial communities in a river-floodplain system (Danube, Austria). Appl. Environ. Microbiol. 71: 609-620.