Present addresses: Biosystems Research, Sandia National Laboratories, Livermore, CA 94551 USA. ‡Department of Biology, Indiana University, Bloomington, IN 47408, USA.
A major protein component of the Bacillus subtilis biofilm matrix
Article first published online: 20 DEC 2005
Volume 59, Issue 4, pages 1229–1238, February 2006
How to Cite
Branda, S. S., Chu, F., Kearns, D. B., Losick, R. and Kolter, R. (2006), A major protein component of the Bacillus subtilis biofilm matrix. Molecular Microbiology, 59: 1229–1238. doi: 10.1111/j.1365-2958.2005.05020.x
- Issue published online: 20 DEC 2005
- Article first published online: 20 DEC 2005
- Accepted 24 November, 2005.
Microbes construct structurally complex multicellular communities (biofilms) through production of an extracellular matrix. Here we present evidence from scanning electron microscopy showing that a wild strain of the Gram positive bacterium Bacillus subtilis builds such a matrix. Genetic, biochemical and cytological evidence indicates that the matrix is composed predominantly of a protein component, TasA, and an exopolysaccharide component. The absence of TasA or the exopolysaccharide resulted in a residual matrix, while the absence of both components led to complete failure to form complex multicellular communities. Extracellular complementation experiments revealed that a functional matrix can be assembled even when TasA and the exopolysaccharide are produced by different cells, reinforcing the view that the components contribute to matrix formation in an extracellular manner. Having defined the major components of the biofilm matrix and the control of their synthesis by the global regulator SinR, we present a working model for how B. subtilis switches between nomadic and sedentary lifestyles.