Abstract:
Microbial life abounds on surfaces in natural, medical and industrial environments. A solid substrate, water and some nutrients are sufficient to allow the construction of a microbial fortress, a so-called biofilm. A better understanding of the functioning of these microbial communities is a challenging and crucial issue, as it constitutes a prerequisite to the optimization of control strategies. Survival properties developed by these surface-associated ecosystems are beginning to be deciphered in the context of rudimentary axenic laboratory biofilms. Gelatinous organic matrices consisting of complex mixtures of self-produced biopolymers ensure the cohesion of these biological structures and contribute to their resistance and persistence on surfaces. Far from being just simple three-dimensional assemblies of identical cells, biofilms are composed of heterogeneous sub-populations with distinctive behavior that contribute to their global ecological success. There is also growing evidence that interspecies interactions may profoundly alter the response of the community to biocide exposure. Heterogeneity appears now as an intrinsic and multi-origin feature of microbial populations and is a major determinant of their beneficial or detrimental functional properties. Recent advances in the development of fluorescence-based approaches dedicated to single-cell analysis provide the opportunity to study microbial communities with an unprecedented level of resolution and to obtain detailed insights on the cell structure, metabolism activity, multicellular behavior and bacterial interactions in complex communities.
Keywords: biofilms, architecture, antimicrobials, bacterial pathogens, multispecies interactions, real-time confocal imaging.