Leuconostoc citreum, a Gram-positive lactic acid bacterium isolated from fermented grains and vegetables, can express various enzymes involved in the biosynthesis of different extracellular polysaccharide (EPS). In this study, Leuconostoc citreum BD1707 was cultured in tomato juice. After 24 and 72 h of culture, samples were collected for ammonium sulfate precipitation followed by in situ activity analysis using native-polyacrylamide gel electrophoresis (native-PAGE). The results showed that Leuconostoc citreum BD1707 could secrete three EPS synthases with molecular masses of about 150, 90 and 80 kDa, respectively, which were higher than those of the known levansucrases.