A Novel Phosphopolysaccharide from Slime-Forming Lactococcus lactis subspecies cremoris SBT 0495

Slime-forming Lactococcus lactis ssp. cremoris SBT 0495 was isolated from starter culture of Finnish fermented milk “Viili”. The slime material, which was obtained (yield of 500 mg/L) from culture supernatant in whey permeate medium, contained 42% carbohydrate and 21% protein. Separation of polysaccharide and protein by anion-exchange chromatography was insufficient. Preparative SDS-PAGE was more effective. The purified polysaccharide (150 mg/L culture broth) contained less than .5% protein. It consisted of carbohydrate and phosphorus in a molar ratio of 5.2:1. Rhamnose, glucose, and galactose were found in a molar ratio of 1:1.45:1.75. Sialic acid, hexosamine, and uronic acid were not detected. Apparent molecular weight was estimated to be 1.7 × 10⁶ by gel permeation chromatography. Thus, we concluded that the main component in the slime was a novel phosphopolysaccharide (phosphorus-containing polysaccharide).