DEGRADATION OF EXTRACELLULAR POLYSACCHARIDES PRODUCED BY CARIOGENIC BACTERIA WITH DEXTRANASE OF CHAETOMIUM GRACILE

Oral streptococci produced extracellular polysaccharide in a medium containing sucrose and formed the artificial plaque on a stainless steel wire. Bacteria which produced highly viscous polysaccharide caused the formation of the thicker plaque than bacteria which produced less viscous polysacharide. Dextranase of Chaetomium gracile hydrolyzed bacterial polysaccharides which had low α-1, 6-glucosidic linkage (47-74%) as well as the commercial dextrans which had high linkage (95%). The enzyme degraded also the artificial plaque of oral streptococci.