Cues for Development

Bacillus subtilis biofilms are elaborate structures, composed of a complex matrix of exopolysaccharides, amyloid fibers, and DNA, which surrounds the bacterial cells. This is the outcome of a coordinated gene expression and cell fate decisions, governed by chemical or physical signals that come from the outer environment, from other cells, or from the matrix itself. Many of those signals are still unknown. In my study, I will try to elucidate the cues to which a bacterial cell is exposed to during biofilm formation, and how they influence its gene expression profile, and biofilm development.

Upper left - top view of Bacillus subtilis wild type colony grown on agar plates with biofilm inducing medium. Upper right - Fluorescence of the colony on the left, expressing YFP from one of the matrix promoters, showing differential expression in different parts of the colony. Bottom - close view of the colony periphery, showing CFP expression from another matrix promoter, in the wild type strain(upper) and three different mutants of the regulatory pathway of biofilm formation (bottom).