부산대학교 도서관

To purchase or authenticate to the full-text of this article, please visit this link: http://dx.doi.org/10.1111/j.1365-2958.2005.05020.x Byline: Steven S. Branda (1), Frances Chu (2), Daniel B. Kearns (2), Richard Losick (2), Roberto Kolter (1) Abstract: Summary 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. Author Affiliation: (1)Department of Microbiology and Molecular Genetics, Harvard Medical School, Boston, MA 02115, USA. (2)Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA. Article History: Accepted 24 November, 2005. Article note: (*) E-mail rkolter@hms.harvard.edu; Tel. (+1) 617 432 1776; Fax (+1) 617 738 7664.