Using a multi-faceted approach to determine the changes in bacterial cell surface properties influenced by a biofilm lifestyle

Abstract

Biofilm formation is a developmental process in which initial reversible adhesion is governed by physico-chemical forces, whilst irreversible adhesion is mediated by biological changes within a cell, such as the production of extracellular polymeric substances. Using two bacteria, E. coli MG1655 and B. cereus ATCC 10987, this study establishes that the surface of the bacterial cell also undergoes specific modifications, which result in biofilm formation and maintenance. Using various surface characterisation techniques and proteomics, an increase in the surface exposed proteins on E. coli cells during biofilm formation was demonstrated, along with an increase in hydrophobicity and a decrease in surface charge. For B. cereus, an increase in the surface polysaccharides during biofilm formation was found as well as a decrease in hydrophobicity and surface charge. This work therefore shows that surface modifications during biofilm formation occur and understanding these specific changes may lead to the formulation of effective biofilm control strategies in the future.

Keywords:

• E. coli
• B. cereus
• biofilm
• surface modification
• proteomics
• spectroscopy

Acknowledgements

The authors wish to acknowledge the UK Engineering and Physical Sciences Research Council (EPSRC) for a studentship for Karunakaran, an Advanced Research Fellowship for Biggs (EP/E053556/01) and further project funding (EP/E053556/01 and EP/E036252/1) and The University of Sheffield for a fee scholarship.

Additional information

Notes on contributors

Joy Mukherjee ^†

†The first two authors contributed equally to this research. †Present address: Swire Institute of Marine Science, University of Hong Kong.