Abstract
Biofilms are aggregated bacterial communities structured within an extracellular matrix (ECM). ECM controls biofilm architecture and confers mechanical resistance against shear forces. From a physical perspective, biofilms can be described as colloidal gels, where bacterial cells are analogous to colloidal particles distributed in the polymeric ECM. However, the influence of the ECM in altering the cellular packing fraction (ϕ) and the resulting viscoelastic behavior of biofilm remains unexplored. Using biofilms of Pantoea sp. (WT) and its mutant (ΔUDP), the correlation between biofilm structure and its viscoelastic response is investigated. Experiments show that the reduction of exopolysaccharide production in ΔUDP biofilms corresponds with a seven‐fold increase in ϕ, resulting in a colloidal glass‐like structure. Consequently, the rheological signatures become altered, with the WT behaving like a weak gel, whilst the ΔUDP displayed a glass‐like rheological signature. By co‐culturing the two strains, biofilm ϕ is modulated which allows us to explore the structural changes and capture a change in viscoelastic response from a weak to a strong gel, and to a colloidal glass‐like state. The results reveal the role of exopolysaccharide in mediating a structural transition in biofilms and demonstrate a correlation between biofilm structure and viscoelastic response.
Original language | English |
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Article number | 2207373 |
Pages (from-to) | 1-11 |
Number of pages | 12 |
Journal | Advanced Science |
Volume | 10 |
Issue number | 27 |
Early online date | 31 Jul 2023 |
DOIs | |
Publication status | Published online - 31 Jul 2023 |
Bibliographical note
Publisher Copyright:© 2023 The Authors. Advanced Science published by Wiley-VCH GmbH.
Data Access Statement
The data that support the findings of this study are available from the cor-responding author upon reasonable request.Keywords
- extracellular exopolysaccharides
- packing fraction
- biofilms
- viscoelasticity
- Payne effect