| Pacific Rim Symposium on Surfaces, Coatings and Interfaces (PacSurf 2014) | |
| Biomaterial Interfaces | Monday Sessions |
| Session BI-MoE |
| Session: | Biofouling |
| Presenter: | Lynne Turnbull, The ithree institute, University of Technology, Sydney, Australia |
| Authors: | E.S. Gloag, The ithree institute, University of Technology, Sydney, Australia L. Turnbull, The ithree institute, University of Technology, Sydney, Australia CB. Whitchurch, The ithree institute, University of Technology, Sydney, Australia |
| Correspondent: | Click to Email |
Introduction: Many bacterial pathogens have the capacity to actively expand their biofilm communities via complex multi-cellular behaviours. We have observed that when the biofilms of Pseudomonas aeruginosa are cultured at the interstitial surface between a coverslip and solidified nutrient media, the resulting biofilms are characterised by an extensive pattern of interconnected trails that emerges as a consequence of the active expansion of these communities.
Aim: To identify the factors governing emergent pattern formation during P. aeruginosa biofilm expansion.
Experimental methods: Bacterial biofilms were cultured at the interstitial space between solidified growth media and a glass coverslip. Biofilm expansion was observed using phase contrast time-lapse microscopy and the topography of the underlying media was imaged using atomic force microscopy (AFM) and 3D optical profilometry after the cells where removed by washing the samples with water.
Results: Our observations have revealed that during the migration of P. aeruginosa biofilms, aggregates of cells at the advancing edge forge furrows as they migrate across the semi-solid media. The formation of a series of interconnecting furrows and the re-inforcing effect of cells traversing these furrows leads to extensive remodelling of the substratum. Our analyses indicate that whilst the furrows are shallow relative to the height of the bacterial cells, this appears to be sufficient to confine cells within the furrows. We have confirmed that furrows guide the migration of biofilm bacteria using PDMS microfabricated channels. The generation and maintenance of the interconnected furrow network therefore accounts for the extensive large scale-patterning that is characteristic of these bacterial biofilms.
Conclusion: Our observations indicate that emergent pattern formation during biofilm expansion across semi-solid media occurs due to self-generated surface modification by the biofilm community.