Structure and Dynamics of a Model Polymer Mixture Mimicking a Levan-Based Bacterial Biofilm of Bacillus subtilis
| Autor: | Andreja Zupančič Valant, Andrej Jamnik, Iztok Dogsa, David Stopar, Elizabeta Benigar, Matija Tomšič, Simon Sretenovic |
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| Rok vydání: | 2016 |
| Předmět: |
0301 basic medicine
030106 microbiology Bacillus subtilis Polysaccharide 03 medical and health sciences X-Ray Diffraction Dynamic light scattering Rheology Electrochemistry Extracellular General Materials Science Spectroscopy chemistry.chemical_classification biology Chemistry Biofilm DNA Surfaces and Interfaces Polymer Condensed Matter Physics biology.organism_classification Fructans 030104 developmental biology Biochemistry Chemical engineering Biofilms Polymer blend |
| Zdroj: | Langmuir. 32:8182-8194 |
| ISSN: | 1520-5827 0743-7463 |
| DOI: | 10.1021/acs.langmuir.6b02041 |
| Popis: | In this paper, we report on the structure and dynamics of biologically important model polymer mixtures that mimic the extracellular polymeric matrix in native biofilm of Bacillus subtilis. This biofilm is rich in nonionic polysaccharide levan, but also contains other biopolymers such as DNA and proteins in small concentrations. Aiming to identify the contribution of each component to the formation of the biofilm, our investigations encompassed dynamic rheology, small-angle X-ray scattering, dynamic light scattering, microscopy, densitometry, and sound velocity measurements. As it turned out, this very powerful combination of techniques is able to provide solid results on the dynamical and structural aspects of the microbiologically and chemically complex biofilm formations. Macroscopic rheological measurements revealed that the addition of DNA to levan solution increased the viscosity, pseudoplasticity, and elasticity of the system. The addition of protein contributed similarly, but also increased the rigidity of the system. This confirms that the presence of minor biofilm components is essential for biofilm formation. DNA and proteins appear to confine levan molecules within their supramolecular structure and, in this way, restrict the role of levan to merely a filling agent. These findings were complemented by small-angle X-ray scattering data, which provided insight into the structure on a molecular scale. One of the essential goals of this work was to compare the structural properties of the native biofilm and synthetic biofilm mixture. |
| Databáze: | OpenAIRE |
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