Sticking together: building a biofilm the Bacillus subtilis way

Bacillus subtilishas emerged as an important model organism for the study of biofilms. In this Review, Kolter, Losick and colleagues discuss the regulation ofB. subtilisbiofilm assembly and highlight two emerging areas in the field: biofilm formation on natural substrates and biofilm disassembly. Biofilms are ubiquitous communities of tightly associated bacteria encased in an extracellular matrix. Bacillus subtilis has long served as a robust model organism to examine the molecular mechanisms of biofilm formation, and a number of studies have revealed that this process is regulated by several integrated pathways. In this Review, we focus on the molecular mechanisms that control B. subtilis biofilm assembly, and then briefly summarize the current state of knowledge regarding biofilm disassembly. We also discuss recent progress that has expanded our understanding of B. subtilis biofilm formation on plant roots, which are a natural habitat for this soil bacterium.