A LIVE/DEAD BacLight Bacterial Viability kit was purchased from Thermo Fisher Scientific (Waltham,MA) and used to stain bacteria. All chemicals, except those particularly described, were purchased from Wako Pure Chemical Industries(Osaka, Japan) and used without further purification. Milli-Qwater (18.2 MΩ·cm; Merck Millipore, Billerica, MA, USA) was used to prepare all aqueous solutions and for rinsing.