Combination of mutanase and dextranase effectively suppressed formation of insoluble glucan biofilm by cariogenic streptococci

Abstract

Cariogenic streptococci produce a-1,3-glucan and a-1,6-glucan, which are the major components of dental biofilms. To investigate the possibility of preventing dental biofilm formation, utility of a combination of mutanase and dextranase was examined in vitro. Experiments: Insoluble glucan biofilms were synthesized by cariogenic streptococci (Streptococcus mutans 10449, S. mutans Ingbritt, Streptococcus sobrinus 6715, and S. sobrinus B13) in the presence of mutanase and/or dextranase in 96-well microplates. Mutanase from Paenibacillus humicus inhibited glucan biofilm formation by these streptococci. This inhibitory effect by mutanase was enhanced in the presence of dextranase. We investigated the effect of combination of these glucosidases on the synthesis of a-1,3-glucan polysaccharides. The combination of recombinant mutanase and dextranase effi- ciently inhibited the synthesis of a-1,3-glucan by recombinant glucosyltrans ferase I on dextran-coated microplates. Conclusion: Mutanase and dextranase should be used in combination as preventive agents to inhibit dental biofilm formation.