Title of the talk: Formation Dynamics And Rheology of Bacterial Biofilms under Fluid Flow.
Biofilms are aggregates of microorganisms embedded in a self-secreted matrix of polymeric substances, which protect the microbial community from chemical and mechanical insults, thereby enhancing their survival and evolutionary success. Due to their resilience, biofilms significantly impact environmental, industrial, and medical settings1,2. Typically, biofilms develop in moist environments where fluids are in motion—a ubiquitous environmental factor that regulates chemical transport and exerts mechanical forces on biofilms3. However, a mechanistic understanding of how fluid dynamics shape biofilm properties remains limited. In our research, we investigate how fluid dynamic conditions drive biofilm assembly and the emergence of distinctive morphological and rheological properties. Our findings reveal that during
biofilm formation in porous structures, the interplay between biological functions and fluid flow controls biofilm morphology and rheology, ultimately affecting the biofilm's physiological protective functions4–6. Specifically, we explore the role of fluid dynamics in the formation of biofilm streamers—filamentous biofilm structures suspended in the flow—which often initiate clogging. Utilizing a newly developed microfluidic platform, we examine how flow conditions determine the mechanical properties of these streamers7,8. For the first time, we demonstrate that biofilm streamers exhibit stress-hardening behavior, a property with profound implications for their protective functions. By elucidating the relationship between flow dynamics and biofilm development, our research not only deepens the physical understanding of biofilm formation but also advances biofilm engineering and eradication.
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M. Caldara, C. Belgiovine, E. Secchi and R. Rusconi, Clin. Microbiol. Infect., 2022, 35, e00221-20.
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D. Marra, T. Karapantsios, S. Caserta, E. Secchi, M. Holynska, S. Labarthe, B. Polizzi, S. Ortega, M. Kostoglou, C. Lasseur, I. Karapanagiotis, S. Lecuyer, A. Bridier, M. Noirot-gros and R. Briandet,Biofilm, 2023, 5, 100109.
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J. D. Wheeler, E. Secchi, R. Rusconi and R. Stocker, Annu. Rev. Cell Dev. Biol., 2019, 35, 213–237.
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S. H. Lee, E. Secchi and P. K. Kang, Proc. Natl. Acad. Sci., 2023, 120, e2204466120.
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D. L. Kurz, E. Secchi, F. J. Carrillo, I. C. Bourg, R. Stocker and J. Jimenez-Martınez, Proc. Natl. Acad. Sci., 2022, 119, e2122202119.
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D. L. Kurz, E. Secchi, R. Stocker and J. Jimenez-martinez, Environ. Sci. Technol., ,DOI:10.1021/acs.est.2c08890.
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E. Secchi, G. Savorana, A. Vitale, L. Eberl, R. Stocker and R. Rusconi, Proc. Natl. Acad. Sci., 2022,119, e2113723119.
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G. Savorana, J. Slomka, R. Stocker, R. Rusconi and E. Secchi, Soft Matter, 2022, 18, 3878–3890.
Short bio: Eleonora Secchi is currently the Group Leader of the BioMatter Microfluidics Group at ETH Zurich, Switzerland. She earned a Ph.D. in Chemical Engineering and Industrial Chemistry from the Polytechnic University of Milan. From 2014 to 2016, she was a postdoctoral fellow at the École Normale Supérieure of Paris, where she focused on measuring water flow from a single carbon nanotube. In 2016, she was awarded an ETH Postdoctoral Fellowship, and in 2018, she started her research group with the support of a SNSF PRIMA grant. Her research lies at the intersection of soft matter physics, fluid dynamics, and microbiology, aiming to understand the physical mechanisms and environmental factors that control bacterial surface colonization and biofilm formation in fluids and on moist surfaces.
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