Water-soluble (1→3),(1→4)-α-D-glucan from mango as a novel inducer of cariogenic biofilm-degrading enzyme.

A water-soluble polysaccharide (WSP) extracted from mango (Mangifera indica L.) fruits has been suggested as a new alternative to mutan for mutanase induction in Trichoderma harzianum. Structural analyses revealed that the purified WSP was a (1→3),(1→4)-α-D-glucan with the molecular mass of ca. 760 kDa in which the (1→4)-linked and (1→3)-linked α-Glcp residues were in a ratio of 1:2.4. When the strain T harzianum CCM F-340 was grown in the presence of WSP, the maximal enzyme productivity obtained after 3 days of cultivation was 34 mU/mL. The mango WSP proved to be a very effective stimulus of mutanase expression giving a 5.1-fold higher than without WSP, transcription. It was shown that the mixture of WSP-induced mutanase and commercial dextranase had a high hydrolytic potential in the reaction with streptococcal mutan, where maximal degrees of solubilization and saccharification of this biopolymer (93.4% and 80%, respectively) were reached within 9h (solubilization) and 24h (saccharification). The mixed enzymatic preparation was also effective in degradation of streptococcal mutan and its removal from cariogenic biofilms. After 3h hydrolysis, only 18.2% of the biofilm remained adhered to the glass surface.