Function of Small basic protein (Sbp) in Staphylococcus epidermidis biofilm matrix assembly: molecular mechanisms and spatio-temporal patterning.

• Applicant: Professor Dr. Holger Rohde
• Subject Area: Metabolism, Biochemistry and Genetics of Microorganisms ; Medical Microbiology and Mycology, Hygiene, Molecular Infection Biology
• Term: since 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 503904498

The assembly of multi-layered bacterial biofilm architectures is a prime example in which bacterial single cell traits are integrated and translated into population behaviour, which in turn provides cues for individual cells to prevail in changing, potentially harsh environments. A hallmark of biofilm formation is production of an extracellular matrix, and in fact, biofilm matrix production and its functional consequences are outstanding examples for emergent functions of bacterial multicellularity. The biofilm matrix consists of a plethora of various biomolecules, referred to as the “matrixome”. Recently, we have identified 18 kDa Small basic protein (Sbp) from S. epidermidis biofilm matrix preparations. Sbp accumulates at the biofilm - substratum interface and in the intercellular space, and thereby functionally supports biofilm formation. In addition, a sbp knock-mutant exhibits striking stationary growth phase defects and increased susceptibility against glycopeptides, both phenotypes being consistent with stringent response gene expression patterns as identified in transciptome analysis. The available evidence supports the hypothesis that Sbp matrix assembly occurs along temporally and spatially orchestrated events, providing an environment which fundamentally affects bacterial physiology. We will use high resolution imaging in combination with biochemical approaches and single cell techniques to dissect principles of Sbp biofilm matrix assembly, identify and characterize involved interaction networks, and to provide insights into the importance of Sbp biofilm matrices for staphylococcal physiology. In the overarching context, the project will provide molecular insights into general principles of dynamics driving bacterial multicellularity, and their inter-relation with bacterial physiology on population and single cell levels.

• DFG Programme: Priority Programmes
• Subproject of: SPP 2389: Emergent Functions of Bacterial Multicellularity