Enzymatic Synthesis of Maltitol and Its Inhibitory Effect on the Growth of <i>Streptococcus mutans</i> DMST 18777

Abstract

This study aimed to synthesize maltitol using recombinant CGTase from Bacillus circulans A11 with β-cyclodextrin (β-CD) and sorbitol as a glucosyl donor and acceptor, respectively, and assess its antibacterial activity. Optimal conditions for producing the highest yield, 25.0% (w/w), were incubation of 1% (w/v) β-CD and sorbitol with 400 U/mL of CGTase in 20 mM phosphate buffer at pH 6.0 and 50 °C for 72 h. Subsequently, maltitol underwent large-scale production and was purified by HPLC. By mass spectrometry, the molecular weight of the synthesized maltitol was 379.08 daltons, corresponding exactly to that of standard maltitol. The relative sweetness of synthesized and standard maltitol was ~90% of that of sucrose. Spot assay on the agar plate showed that maltitol inhibited the growth of Streptococcus mutans DMST 18777 cells. In addition, the MIC and MBC values of synthesized and standard maltitol against S. mutans were also determined as 20 and 40 mg/mL, respectively. These results show that the synthesized maltitol can be produced at high yields and has the potential to be used as an anticariogenic agent in products such as toothpaste.

Keywords

• antibacterial activity
• anticariogenic activity
• cyclodextrin glycosyltransferase (CGTase)
• maltitol
• <i>Streptococcus mutans</i>