Mutanase of Paenibacillus humicus from Fermented Food Has a Potential for Hydrolysis of Biofilms Synthesized by Streptococcus mutans

Abstract

Mutanase is an α-1,3-glucanase that cleaves the α-1,3-glucosidic linkages of glucan polysaccharides termed mutan. There has been interest in mutanase as it has the potential to be considered in preventive medicine. Previously, we identified the mutanase of Paenibacillus humicus from fermented soybeans and observed that the enzyme hydrolyzed insoluble glucans and mutan in vitro. Here we focused on the ability of mutanase in preventing dental caries. We proposed that the enzyme participates in the degradation of insoluble glucan biofilms in microplates, which were used as a model of biofilms on tooth surface. In this study, we investigated the potential of mutanase to hydrolyze insoluble glucan biofilms synthesized by a typical cariogenic streptococcus, Streptococcus mutans 10449, in 96-well microplates. The mutanase specifically hydrolyzed insoluble glucan biofilms composed of insoluble glucans synthesized by S. mutans. The mutanase hydrolyzed approximately 60% of S. mutans glucan biofilms in the wells and liberated oligosaccharides from the glucan films. We observed that recombinant mutanase could hydrolyze mutan biofilms, and the enzyme was characterized as an endo-α-1,3-glucanase because its hydrolysis of mutan biofilms, resulted in the predominant liberation of α-1,3-glucan tetrasaccharides. The present study suggests that Paenibacillus mutanase from fermented soybeans has potential application in preventive medicine because of its ability to degrade oral insoluble glucan biofilms.

A novel thermostable α-1,3-glucanase from <i>Streptomyces thermodiastaticus</i> HF 3-3

“…The pH dependence of a-1,3-glucanase HF65 activity was almost similar to those of bacterial a-1,3-glucanases that have been reported to exhibit optimum activity at acidic pH regions (Fuglsang et al, 2000;Imai et al, 1977;Meyer and Phaff, 1980;Pleszczy¢ nska et al, 2010;Shimotsuura et al, 2008;Suyotha et al, 2014;Tsumori et al, 2011). The effect of temperature was also investigated in the range 30-80∞C (Fig.…”

“…Thus, the enzyme is of interest due to its potential use in the removal of dental plaque and the biological control of pathogenic fungi. Some studies have demonstrated the ability of a-1,3-glucanases to reduce the plaque synthesized by Streptococcus species, as well as to inhibit plaque formation (Fuglsang et al, 2000;Pleszczy¢ nska et al, 2010;Shimotsuura et al, 2008;Tsumori et al, 2011;Wiater et al, 2004Wiater et al, , 2008. Moreover, they indicated that the degradation of plaque by the enzyme was more effectively performed in combination with dextranase (Fuglsang et al, 2000;Shimotsuura et al, 2008).…”

“…Another problem is the stability of the enzyme under the specific conditions conducted for oral care products, or a pesticide. Unfortunately, none of the characterized a-1,3-glucanases exhibit extreme stability, such as a high thermal stability, which is one of the properties desired for industrial utilization; almost all characterized a-1,3-glucanases were unstable above 65∞C (Fuglsang et al, 2000;Imai et al, 1977;Meyer and Phaff, 1980;Pleszczy¢ nska et al, 2010;Shimotsuura et al, 2008;Suyotha et al, 2013Suyotha et al, , 2014Tsumori et al, 2011). In recent years, genetic manipulations have been used to develop the properties of target enzymes.…”

Sustainable inhibition efficacy of liposome-encapsulated nisin on insoluble glucan-biofilm synthesis byStreptococcus mutans

“…Insoluble glucan-biofilms were generated using S. mutans 10449 (ATCC; absorbance of 0.05 at 600 nm, at the middle logarithm stages) in 96-well microplates (Corning, NY, USA; Tsumori et al, 2011). S. mutans supplemented with 100 µL of Todd Hewitt Broth (Invitrogen, Carlsbad, CA, USA), 50 µL of 1.0% sucrose, and 50 µL of increasing amounts of naked nisin (0.1-100 pmol) in 10 mM sodium citrate buffer (pH = 5.0) were placed in each well and incubated for 1 h at 37°C.…”

“…Insoluble glucans in each well were washed with 10 mM sodium phosphate buffer (pH = 7.0) and suspended in 0.2 mL of 1.0 M sodium hydroxide. Alkali-soluble glucans were recovered and glucose levels quantified as glucan-biofilms by the phenol-sulfuric acid method (Tsumori et al, 2011).…”