Capsular polysaccharides secreted by building façade colonisers: characterisation and adsorption to surfaces

Abstract

Exopolymers secreted by algal and cyanobacterial strains isolated from building façades were imaged by microscopy techniques. They were extracted and characterised to investigate their possible contribution to interactions with solid surfaces. The polymers were polysaccharides, with anionic and hydrophobic properties varying between the various strains. Capsular polysaccharides extracted from a strain of Klebsormidium flaccidum adsorbed in higher amounts on hydrophobic than on hydrophilic surfaces. These results tend to confirm the hypothesis that exopolymers are important in the colonisation process of microorganisms to surfaces.

Keywords:

• Algae
• cyanobacteria
• biofilms
• buildings
• polysaccharides
• adsorption

Acknowledgements

This study was funded by Rhodia PPMC, Hexion Specialty Chemicals and by grant No. 294/2003 from ANRT (Association Nationale de la Recherche Technique). The authors would like to thank Dr T. Coradin and Dr M. Turmine (Université Paris VI) for, respectively, zetameter and tensiometer accessibility, and Dr V. Geoffroy (Rhodia) for her help in reflectometry analysis.