Bacteria biofilms are multicellular communities where bacteria self-produce an extracellular matrix (ECM) made of DNA, proteins and polysaccharides. These biofilms not only confer resistance against environmental stress and antibiotics, but their physical and chemical properties can also be modulated upon exposure to external stimuli. For example, biofilm ECM containing functional amyloids fibrils show higher mechanical robustness and chemical resistance. Amyloids are also known for contributing to the adhesion properties of the biofilm. Thus, there has been an increasing interest in using bacterial amyloids as biomaterials for various applications. Yet, much is to learn about these ECM components in order to fully benefit from their properties and develop stable and functional biofilm-derived materials.

To clarify how ECM components, affect biofilm properties, we investigate the physical-chemical properties of curli amyloid fibrils and the naturally modified cellulose (pEtN-cellulose). Each ECM component was purified from E. coli biofilms producing only curli amyloid fibrils, or only pEtN-cellulose, or both components [1][2].

Together with electronic microscopy, FT-IR and fluorescence spectroscopy were used to characterise the conformation of the different fibrils [3]. Assays studying the interaction of both fibrils were also carried out. The results provide fundamental knowledge on the biophysical features of amyloid and pEtN-cellulose fibrils and constitute one further step towards understanding and controlling biofilm functional properties.