A microfluidic platform for characterizing the structure and rheology of biofilm streamers


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Date

2022-05-28

Publication Type

Journal Article

ETH Bibliography

yes

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Data

Abstract

Biofilm formation is the most successful survival strategy for bacterial communities. In the biofilm lifestyle, bacteria embed themselves in a self-secreted matrix of extracellular polymeric substances (EPS), which acts as a shield against mechanical and chemical insults. When ambient flow is present, this viscoelastic scaffold can take a streamlined shape, forming biofilm filaments suspended in flow, called streamers. Streamers significantly disrupt the fluid flow by causing rapid clogging and affect transport in aquatic environments. Despite their relevance, the structural and rheological characterization of biofilm streamers is still at an early stage. In this work, we present a microfluidic platform that allows the reproducible growth of biofilm streamers in controlled physico-chemical conditions and the characterization of their biochemical composition, morphology, and rheology in situ. We employed isolated micropillars as nucleation sites for the growth of single biofilm streamers under the continuous flow of a diluted bacterial suspension. By combining fluorescent staining of the EPS components and epifluorescence microscopy, we were able to characterize the biochemical composition and morphology of the streamers. Additionally, we optimized a protocol to perform hydrodynamic stress tests in situ, by inducing controlled variations of the fluid shear stress exerted on the streamers by the flow. Thus, the reproducibility of the formation process and the testing protocol make it possible to perform several consistent experimental replicates that provide statistically significant information. By allowing the systematic investigation of the role of biochemical composition on the structure and rheology of streamers, this platform will advance our understanding of biofilm formation.

Publication status

published

Editor

Book title

Journal / series

Volume

18 (20)

Pages / Article No.

3878 - 3890

Publisher

Royal Society of Chemistry

Event

Edition / version

Methods

Software

Geographic location

Date collected

Date created

Subject

Organisational unit

09467 - Stocker, Roman / Stocker, Roman check_circle

Notes

Funding

179834 - The role of ambient flow and physico-chemical microenvironment in determining the microstructure of the biofilm matrix (SNF)
202188 - BioEncounters – where physics encounters microbial ecology (SNF)

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