סמינר בכימיה פיזיקלית : A multiscale study of bacterial biofilms. From isolated components to multicellular organisms
Liraz Chai, The Hebrew University of Jerusalem
Biofilms are multicellular microbial communities that encase themselves in a secreted network of biopolymers and attach to surfaces and interfaces. From a soft matter perspective, biofilms are regarded as colloidal hydrogels, with the cells playing the role of colloids and the extracellular matrix (ECM) compared with a cross-linked hydrogel. However, from a biological perspective, biofilms are heterogeneous communities that organize in space and time into functionally distinct subgroups, in a process resembling differentiation in higher organisms. Biofilm heterogeneity has been demonstrated at the cellular level, but the molecular level has been neglected. In this talk we focus on the properties of water, ECM, and metal ions in biofilms. Using simultaneous X-ray diffraction/fluorescence (XRD/XRF), we portrayed the dominant structural features in Bacillus subtilis biofilms and mapped them in space and time. Particularly, we revealed molecular-level structural hierarchy in the biofilms, that followed biofilm macroscopic morphology. Mapping the XRD and XRF signatures of intact biofilms in space and time allowed us to suggest an inclusive view of biofilm development, linking the ECM and the spores via the transport of water and metal ions.
מארגני הסמינר: פרופ' חיים דיאמנט וד"ר שלומי ראובני