Submitted to: Microbiological Societies Federation Of European
Publication Type: Proceedings
Publication Acceptance Date: September 15, 1995
Publication Date: N/A
Leuconostoc mesenteroides is well known as the source of dextrans, glucans in which alpha-(1-6) linkages predominate. As early as 1954, rare strains of L. mesenteroides, such as NRRL B-1355, were recognized as producing an additional polysaccharide, subsequently determined to be an alpha-D-glucan with the unique backbone structure of alternating alpha-(1-6) and alpha-(1-3) linkages. This polymer was named "alternan" by Cote and Robyt. Alternan and its derivatives have potential commercial applications as low-viscosity bulking agents, extenders, etc. in foods and cosmetics. However, all naturally occurring strains of L. mesenteroides known to produce alternan also produce dextran in roughly equal amounts. Separations of alternan from dextran, and alternansucrase from dextransucrase, have been achieved only with difficulty. Molecular approaches to this problem have met with little success to date. We consequently adopted a mutagenesis approach to the improvement of L. mesenteroides strains for enhanced alternansucrase production.