Submitted to: Journal of Industrial Microbiology and Biotechnology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 26, 2004
Publication Date: February 1, 2005
Citation: Cote, G.L., Leathers, T.D. 2005. A method for surveying and classifying Leuconostoc spp. glucansucrases according to strain-dependent acceptor product patterns. Journal of Industrial Microbiology and Biotechnology. 32(2):53-60. Interpretive Summary: We screened many strains of food-grade bacteria for their ability to convert sucrose (cane or beet sugar) plus a corn sugar (maltose) into mixtures of complex carbohydrates. Different strains were found to produce different patterns of complex carbohydrates. These patterns could generally be divided into four types. This new method is useful for classifying new strains based on their ability to produce certain types of carbohydrate structures and will be of use to us in our efforts to produce novel carbohydrate-based prebiotics.
Technical Abstract: A number of Leuconostoc spp. strains were screened for their ability to produce glucansucrases and carry out acceptor reactions with maltose. Acceptor products were analyzed by thin-layer chromatography, and it was discovered that they could be grouped into four distinct categories, based on oligosaccharide product patterns. These patterns corresponded with structural features of the dextrans each strain is reported to produce. Strains that produced a typical dextran, characterized by a predominantly linear alpha(1-6)-linked D-glucan chain with a low to moderate degree of branching, produced a homologous series of isomaltooligosaccharides via acceptor reactions. Strains that produced dextrans with moderate to high levels of alpha(1-2) branch points, exemplified by NRRL B-1299, synthesized the same isomaltodextrins as well as another series of oligosaccharides migrating slightly faster in our TLC system. Strains that produced dextrans with higher levels of alpha(1-3)-branches, such as NRRL B-742, synthesized isomaltodextrins plus a series of oligosaccharides that migrated slightly more slowly on TLC. And finally, strains known to produce alternansucrase produced isomaltodextrins plus oligoalternans. Within a given type, variability exists in the relative proportions of each product. The data presented here may be useful in selecting strains for the production of specific types of oligosaccharides, for example as prebiotics.