ARS | Publication request: Insoluble glucans from planktonic and biofilm cultures of mutants of Leuconostoc mesenteroides NRRL B-1355

Submitted to: Applied Microbiology and Biotechnology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: October 22, 2008
Publication Date: January 23, 2009
Citation: Cote, G.L., Leathers, T.D. 2009. Insoluble glucans from planktonic and biofilm cultures of mutants of Leuconostoc mesenteroides NRRL B-1355. Applied Microbiology and Biotechnology. 82:149-154.

Interpretive Summary: The food-grade lactic acid bacterium Leuconostoc mesenteroides strain NRRL B-1355 is becoming increasingly important as a source of enzymes, carbohydrates, and polymers. This study shows that the bacteria make insoluble polymers that are very similar, if not identical, to those produced by the bacteria that form biofilms on teeth. This may help scientists understand how these bacteria form sticky insoluble masses on surfaces, and may also suggest new technological applications of the insoluble materials, such as in adhesives and fibers.

Technical Abstract: Leuconostoc mesenteroides strain NRRL B-1355 produces the soluble exopolysaccharides alternan and dextran in planktonic cultures. Mutants of this strain are available that are deficient in the production of alternan, dextran, or both. Our recent work demonstrated that biofilms from all strains contained insoluble polysaccharides. We now find that biofilm cultures of all strains produce insoluble polysaccharide composed of D-glucose polymers with contiguous sequences of alpha(1-3) and alpha(1-6) linkages. In addition, planktonic cultures of the wild-type also produce this insoluble mixture in association with the cell mass. This material is similar to the insoluble glucan matrix known as mutan formed by cariogenic strains of streptococci. The production of insoluble mutan-like glucans may be more widespread among Leuconostoc spp. than previously recognized.