Effects of Norspermidine on Dual‐Species Biofilms Composed of Streptococcus mutans and Streptococcus sanguinis

Figure 4

SEM imaging, metabolic activity, and acid production of S. mutans and S. sanguinis dual-species biofilms. (a) SEM imaging of dual-species biofilms: (A–E) biofilm in the 0.0 mM norspermidine group, 7.0 mM norspermidine group, 3.5 mM norspermidine group, pH-adjusted (pH = 7.0) 7.0 mM norspermidine group, and pH-adjusted (pH = 7.0) 3.5 mM norspermidine group, respectively (5000x, scale bar = 20 μm); (F–J) biofilm in the 0.0 mM norspermidine group, 7.0 mM norspermidine group, 3.5 mM norspermidine group, pH-adjusted (pH = 7.0) 7.0 mM norspermidine group, pH-adjusted (pH = 7.0) 3.5 mM norspermidine group, respectively (20000x, scale bar = 5 μm); (b) metabolic activity of dual-species biofilm in different groups as revealed by MTT assay; (c) lactic acid production of dual-species biofilm revealed by lactic acid measurement. Data are presented as mean ± standard deviation, and values with dissimilar letters are significantly different from each other ().

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