Characterization of dextran-producing Leuconostoc strains

Twelve dextran-producing Leuconostoc strains were characterized according t o their antibiotic susceptibilities, carbohydrate fermentation profiles, su crase activity patterns and plasmid content. All the strains tested were re sistant to the antibiotics sulphathiazole, trimethoprim and vancomycin, and could be separated into two groups based on whether or not they could ferm ent melibiose and raffinose. Six Leuconostoc strains possessed plasmids and many produced unique sucrase activity patterns in polyacrylamide gels. The se data will aid in distinguishing among physiologically similar dextran-pr oducing leuconostocs, frequently used in research and industry.