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 9 h (solubilization) and 24 h (saccharification). The mixed enzymatic preparation was also effective in degradation of streptococcal mutan and its removal from cariogenic biofilms. After 3 h hydrolysis, only 18.2% of the biofilm remained adhered to the glass surface.