Fig. 5.

Activity of mannitol dehydrogenase (a) and content of extracellular DNA (b) in bacterial biofilm affected by the saponin and antibiotics ($\overline{x}+s$, n = 5). Data were measured respectively by a decrease in the absorbance of reactive mixture at 340 nm and biofilm lysate at 260 nm compared to untreated controls. ∆ 340 nm reflects decrease of mannitol dehydrogenase activity, and ∆ 260 nm reflects decrease of eDNA in biofilm. a, p < 0.01, compared with amoxicillin; b, p < 0.01, compared with the saponin; c, p < 0.01, compared with erythromycin. Amo: amoxicillin; Sap: saponin; Ery: erythromycin