The Exo-Polysaccharide Component of Extracellular Matrix is Essential for the Viscoelastic Properties of Bacillus subtilis Biofilms
Journal article, 2020

Bacteria are known to form biofilms on various surfaces. Biofilms are multicellular aggregates, held together by an extracellular matrix, which is composed of biological polymers. Three principal components of the biofilm matrix are exopolysaccharides (EPS), proteins, and nucleic acids. The biofilm matrix is essential for biofilms to remain organized under mechanical stress. Thanks to their polymeric nature, biofilms exhibit both elastic and viscous mechanical characteristics; therefore, an accurate mechanical description needs to take into account their viscoelastic nature. Their viscoelastic properties, including during their growth dynamics, are crucial for biofilm survival in many environments, particularly during infection processes. How changes in the composition of the biofilm matrix affect viscoelasticity has not been thoroughly investigated. In this study, we used interfacial rheology to study the contribution of the EPS component of the matrix to viscoelasticity of Bacillus subtilis biofilms. Two strategies were used to specifically deplete the EPS component of the biofilm matrix, namely (i) treatment with sub-lethal doses of vitamin C and (ii) seamless inactivation of the eps operon responsible for biosynthesis of the EPS. In both cases, the obtained results suggest that the EPS component of the matrix is essential for maintaining the viscoelastic properties of bacterial biofilms during their growth. If the EPS component of the matrix is depleted, the mechanical stability of biofilms is compromised and the biofilms become more susceptible to eradication by mechanical stress.

bicone method

interfacial rheology

biofilms

exopolymeric matrix

Author

Santosh Pandit

Chalmers, Biology and Biological Engineering, Systems and Synthetic Biology

Mina Fazilati

Chalmers, Industrial and Materials Science, Engineering Materials

Karolina Gaska

University of Bristol

Abderahmane Derouiche

Chalmers, Biology and Biological Engineering, Systems and Synthetic Biology

Tiina Nypelö

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry

Ivan Mijakovic

Chalmers, Biology and Biological Engineering, Systems and Synthetic Biology

Roland Kádár

Chalmers, Industrial and Materials Science, Engineering Materials

International Journal of Molecular Sciences

16616596 (ISSN) 14220067 (eISSN)

Vol. 21 18 6755

Subject Categories

Other Mechanical Engineering

Cell and Molecular Biology

Other Materials Engineering

Areas of Advance

Health Engineering

Materials Science

DOI

10.3390/ijms21186755

PubMed

32942569

More information

Latest update

11/9/2020