Author:

Keywords:

11Q5N24N#57045718, G0H3122N#56761277

Abstract:

Biofilms are bacterial communities of cells enclosed in a matrix of self-produced extracellular polymeric substances. While unwanted in many domains such as wound healing, food production, medical treatments and industrial fouling, biofilms are also growing in importance as a positive tool in biotechnological applications including bioremediation, biofertilization and energy production. Biofilms are viscoelastic in nature, allowing them to adapt to a changing environment, and significantly complicating their mechanical removal. Understanding the mechanical properties of biofilms is thus a crucial aspect to many applications. However, their rheological characterization is difficult due to the inherent change of the heterogeneous film structure when transferring and loading onto conventional measurement tools. In this work we demonstrate how to adapt conventional rheometry to the study of biofilms. More precisely, the evaluation and use of disposable PDMS geometries where the biofilm can be grown under relevant conditions (flow of nutrients, temperature) is shown [1]. For the geometries, custom-made 3D-printed molds are used to prepare biocompatible and oxygen-permeable PDMS plates. The setup developed here allows to grow biofilm in situ, directly on the PDMS geometry, eliminating the need to scrape and transfer the biofilm. Furthermore, the setup allows to feed the biofilm with nutrients via a channel structure integrated into the PDMS geometries, allowing to obtain long-term, time-resolved information of the rheological properties and the role of nutrient conditions. [1] Geisel, S., Secchi, E., & Vermant, J. (2022). Experimental challenges in determining the rheological properties of bacterial biofilms. Interface Focus, 12(6), 20220032.