PUB - Publikationen an der Universität Bielefeld

A broad variety of bacteria including the Rhizobiaceae are able to secrete polysaccharides. Sugar polymers that form an adherent cohesive layer on the cell surface are designated capsular polysacharides (CPS), whereas the term exopolysaccharide (EPS) is used for polysaccharides with little or no cell association. Due to the variation of monosaccharide sequences, condensation linkages and non-carbohydrate decorations, an infinite array of structures can be provided by this class of macromolecules. Different rheological properties depend on the structure and the molecular weight of EPS. These properties and the location of EPS, forming the outer layer of the cell surface, contribute to the cell protection against environmental influences, attachment to surfaces, nutrient gathering and to antigenicity (Costerton et al., 1987, Sutherland 1988, Whitfield 1988, Beveridge and Graham 1991). The structural diversity of oligosaccharides derived from EPS enables them to function additionally as informational molecules in cell-cell-communications. Finally, many symbiotic bacteria of the Rhizobiaceae use oligosaccharides as signal molecules in the interaction with their host plant.