Fig. 2.

Abundant biofilm matrix molecules. In the matrix of biofilms, polysaccharides are important components, including alginate, fructan and other capsular polysaccharides, as well as Psl and other aggregation polysaccharides. Alginate is a highly molecular-weight acetylated polymer and is an anionic polysaccharide composed of β-1-4 glycosidic bond-linked α-α L-guluronic acid and β-D-mann β uronic acid. Levan is a high molecular weight b-2,6 polyfructose with extensive branching through the b-2,1 bond. Psl polysaccharides are neutral polysaccharides consisting of pentasaccharide repeating units composed of D-mannose, D-glucose, and L-rhamnose. In addition, there are a large number of proteins, enzymes, eDNA, lipids and other important components in the matrix