Targeting sigma factor controlled signaling pathways to modulate biofilm growth and composition

Abstract

Stress‐responsive transcription factors (TFs) and alternative sigma factor TFs control a multitude of downstream targets, some of which may have a direct impact on the formation of bacterial biofilm and the composition of the extracellular polymeric matrix (EPS) surrounding the biofilm. We explore the effect of moderate overexpression of several different alternative sigma factor TFs on biofilm growth using a variety of biochemical and analytical assays. Biofilm growth is monitored by a dye‐binding microtiter plate assay, and the EPS composition, specifically the concentration of proteins and polysaccharides, is monitored by colorimetric assays and FT‐IR spectroscopy. We monitor the known downstream targets of these TFs using quantitative real‐time PCR (qPCR) to confirm TF overexpression. Currently, we are exploring the impact of overexpressing sigma factors rpoH, normally upregulated upon heat shock, and rpoF, an alternative sigma factor responsible for the expression of chemotaxis receptors and flagellar assembly, on biofilm formation and composition.Support or Funding InformationThis work was supported by Oberlin College.