Research - Institute of Biophysics - Bionanoscience Research Unit - Cell Biophysics Research Group

senior research associate

Lóránd KELEMEN senior research associate
Lajos KESZTHELYI professor emeritus
Pál ORMOS scientific adviser
Krisztina NAGY research associate
Eszter CSÁKVÁRI research associate
Ágnes ÁBRAHÁM Ph.D. student
Tamás FEKETE Ph.D. student
András BUZÁS scientific administrator
László DÉR scientific administrator
Gaszton VIZSNYICZAI scientific administrator


Two important recent milestones are shaping our view of microbial life: the discovery of social interactions of microbes, and the realization of the importance of the spatial and temporal structure of the environment. Following these our research primarily focuses on cell-cell and cell-environment interactions and their importance in the formation, development and evolution of microbial communities. In order to study these phenomena experimentally we are using micro- and nanofabrication technologies to create precisely engineered, physically and chemically defined bacterial habitats.

By using microfabricated structures we are studying physical (hydrodynamic) cell-cell and cell-surface interactions of swimming bacteria. We have demonstrated the existence a hydrodynamic entrapment effect that promotes cell adhesion and biofilm formation.

We are also studying the effect of heterogeneous environments on bacterial populations. For this we have developed a microfluidic device to create precise chemical concentration gradients. We are testing the chemoeffector (attractant or repellent) potential of a wide array of chemicals from antibiotics to quorum sensing signaling molecules. The device is also suitable for exploring the interaction of chemically coupled but spatially separated bacterial populations. With this method we are studying intra- and interspecies interactions of bacteria that are based on excreted molecules.

We are using microfluidic chips as bacterial habitats to study different ecological scenarios. We have used microchips to model a fragmented habitat structure and showed that it increases the survival of cooperating bacterial strains in a cheater-cooperator competition scenario.

Selected publications

Hol, F.J.H, Galajda, P., Nagy, K., Woolthuis, R.G., Dekker, C., Keymer, J.E. (2013). Spatial Structure Facilitates Cooperation in a Social Dilemma: Empirical Evidence From a Bacterial Community. PLoS ONE 8: e77042.

Maennik, J., Driessen, R., Galajda, P., Keymer, J.E., Dekker, C. (2009). Bacterial Growth and Motility in Sub-Micron Constrictions. Proceedings of the National Academy of Sciences of the United States of America 106: 14861–14866.

Galajda, P., Keymer, J., Chaikin, P., Austin, R. (2007). A Wall of Funnels Concentrates Swimming Bacteria. Journal of Bacteriology 189: 8704–8707.

Keymer, J.E, Galajda, P., Muldoon, C., Park, S., Austin, R.H. (2006). Bacterial Metapopulations in Nanofabricated Landscapes. Proceedings of the National Academy of Sciences of the United States of America 103: 17290–17295