title: Production and partial characterization of the extracellular polysaccharides from oral Streptococcus salivarius.
abstract: The production of polysaccharides from sucrose by extracellular enzymes from oral Streptococcus salivarius isolates and the physico-chemical properties of water-insoluble products (IPs) were investigated. Extracellular enzymes from all the 18 strains tested produced insoluble alpha-D-glucans (IGs) as well as soluble beta-D-fructans, and formed adhering deposits on glass. Generally, the IPs (mostly IGs) of S. salivarius strains differed from the S. sobrinus IPs by (a) containing significant proportions of alpha-D-(1----4)-, in addition to alpha-D-(1----3)- and alpha-D-(1----6)-glucosyl linkages, and much higher proportions of alpha-D-(1----3) than alpha-D-(1----6) linkages, (b) being more susceptible to hydrolysis by mutanase than by dextranase, (c) possessing low or no streptococcal cell-agglutinating ability, and (d) showing weaker adhesion to a glass surface. The degree of the polysaccharide adherence differed greatly among the S. salivarius strains and, therefore, they were divided into three groups of adherence producers; heavy, moderate, and slight. The IPs of the three groups contained, generally in descending order, a higher proportion of higher-molecular-weight fractions, and consisted of higher proportions of IG containing higher proportions of -(1----6)-alpha-D and -(1----4)-alpha-D glucosyl linkages and (1----3,6) branches, but showed higher susceptibility to hydrolysis by mutanase as well as dextranase. Thus, the production and the properties of extracellular insoluble alpha-D-glucans from sucrose differ considerably between oral S. salivarius and cariogenic S. sobrinus.
authors.affiliation: Department of Preventive Dentistry, Kagoshima University Dental School, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Eifuku
authors.forename: A
authors.initials: A
authors.lastname: Yoshimitsu-Narita
authors.forename: S
authors.initials: S
authors.lastname: Sato
authors.forename: T
authors.initials: T
authors.lastname: Yakushiji
authors.forename: M
authors.initials: M
authors.lastname: Inoue
mesh_terms: D000371:Agglutination; D004693:Glucan Endo-1,3-beta-D-Glucosidase / Q000378:metabolism; D005959:Glucosidases; D006026:Glycoside Hydrolases / Q000378:metabolism; D006801:Humans; D007700:Kinetics; D008745:Methylation; D009055:Mouth / Q000382:microbiology; D011135:Polysaccharides, Bacterial / Q000138:chemical synthesis* / Q000302:isolation & purification; D013291:Streptococcus / Q000201:enzymology* / Q000302:isolation & purification
chemical_list: D011135:Polysaccharides, Bacterial; D005959:Glucosidases; D006026:Glycoside Hydrolases; D004693:Glucan Endo-1,3-beta-D-Glucosidase; C021780:exo-1,3-alpha-glucanase