title: Sucrase and maltase activities in supragingival dental plaque in humans of streptococcal, actinomyces and lactobacilli species.
abstract: 20 reference strains and 72 isolated strains from dental plaque of streptococci, actinomyces, and lactobacilli species were examined for sucrase and maltase activities. The type of sucrase in the different strains was determined by use of the alpha-glucosidase inhibitor, acarbose. The enzyme activities were determined as formation of monosaccharide, and quantitated spectrophotometrically. Although variations occurred in enzyme activities between reference and isolated strains, the same general pattern was noticed. Strains of Streptococcus mutans and S. salivarius showed regularly the highest sucrase activities, followed by strains of Actinomyces viscosus and A. naeslundii. Most lactobacilli belonged to the bacteria with low sucrase activity like S. sanguis and S. mitior. In some lactobacilli strains, however, a high sucrase activity was observed. The level of sucrase activity in S. mutans strains was dependent on biotype/serotype, as strains of biotype V/serotype e showed high activities, biotypes I and IV corresponding to serotypes c, f, and d showed intermediate activity, and biotype III/serotype a always showed low activity. In most of the strains the sucrases were composed of enzymes with specificity against both alpha-glucosidic linkage and beta-fructosidic linkage of the sucrose molecule, but in varying ratios. In all species, exept S. sanguis and S. mitior, lower maltase than sucrase activity was observed, but even in the two species mentioned the maltase activities were relatively low. On the basis of observations of selected reference strains in every species examined both sucrases and maltases are to some extent inducible.
mesh_terms: D000190:Actinomyces / Q000201:enzymology; D001419:Bacteria / Q000201:enzymology*; D003773:Dental Plaque / Q000382:microbiology*; D005959:Glucosidases / Q000378:metabolism*; D006801:Humans; D007778:Lactobacillus / Q000201:enzymology; D013291:Streptococcus / Q000145:classification / Q000201:enzymology; D013393:Sucrase / Q000378:metabolism*; D000520:alpha-Glucosidases / Q000378:metabolism*
chemical_list: D005959:Glucosidases; D000520:alpha-Glucosidases; D013393:Sucrase