Degradation of Streptococcus mutans Water-Soluble Glucans by Dextran-Glucosidase from Streptococcus mitis

• Published in: Caries research Vol. 21; no. 1; pp. 1 - 6
• Main Authors: Sund, Marie-Louise, Ericsson, C., Linder, L.E., Branting, Christina
• Format: Journal Article
• Language: English
• Published: Basel, Switzerland 01.01.1987
• Subjects: Basic Science; Chromatography, Paper; Dentistry; Glucans - analysis; Glucans - metabolism; Glucosidases - metabolism; Polysaccharides, Bacterial - analysis; Polysaccharides, Bacterial - metabolism; Solubility; Streptococcus - enzymology; Streptococcus mutans - metabolism; Sucrose - metabolism; Water; Glucan degradation; Dextran-glucosidase; Streptococcus mitis; Streptococcus mutans
• ISSN: 0008-6568; 1421-976X
• DOI: 10.1159/000260995

Dextran-glucosidase EC 3.2.1.70 isolated from Streptococcus mitis ATCC 903 was tested for activity on water-soluble polysaccharides produced from sucrose by four Streptococcus mutans strains: AHT, BHT, IB and B13. Two fractions of glucans with molecular weights of about 40,000 and < 9,400 were obtained by gel filtration of water-soluble glucans of S. mutans. The elution profiles were essentially the same for the four strains. Upon incubation of these glucans with dextran-glucosidase, only 10–30% of the low-molecular weight glucans remained. The high-molecular weight glucans were resistant to dextran-glucosidase or were degraded to 25%. Glucose was the degradation product. The yields of water-soluble polysaccharides from the S. mutans strains varied between 17.6 mg/ml culture supernatant (IB) to 1.4 mg/ml (B13).