extract inhibits biofilm formation in .

is capable of biofilm formation. In this study, we investigated the effects of aqueous extract on growth and biofilm formation. Aqueous extracts significantly inhibited both bacterial growth and biofilm formation. However, methanolic extracts inhibited neither. Aqueous extracts were deactivated by heating but were not deactivated by light exposure. The ingredients retained the inhibitory effect on the bacterial growth and biofilm formation after ultrafiltration of aqueous extract. Furthermore, polyphenol-rich extracts inhibited bacterial growth, thus, polyphenols are possible to be an active ingredient. We observed the biofilm by scanning electron microscopy, and quantitative and qualitative differences in the biofilm and cells morphology. Interestingly, the biofilm treated aqueous extracts remained premature. We postulated that premature biofilm formation was due to the inhibition of swarming motility. Indeed, aqueous extracts inhibited swarming motility. These results demonstrate that growth and biofilm formation are inhibited by aqueous extracts.