Fig. 2

#858 showed decreased biofilm formation ability. a The biofilms formation of WT and #858 based on the crystal violet assay. Each values is mean ± SD (n = 6). b Crystal violet staining of biofilms. c Growth curves of WT and #858 strains. The OD600 values were recorded at 1 h interval during the 20-h cell growth period at temperature of 37 °C (n = 6). d The scanning electron microscopy images of biofilms under 1000 × and 20,000 × magnified visual field. e The 3-dimensional reconstruction of biofilms (bacteria, stained green; EPS, stained red). f The volume of EPS and bacteria, calculated according to 3 random sights of controlled biofilms (n = 3). g The quantitative data of the water-insoluble polysaccharide amount of each well from WT and #858, measured by anthrone method at 625 nm (n = 6). h The expression of EPS synthesis related genes of S. mutans (n = 3). Data are presented as mean ± standard deviation. (* p < 0.05, *** p < 0.001)