Department of Chemical Engineering, Stanford University, Stanford, California 94305, United States.
Langmuir. 2013 Jan 22;29(3):920-6. doi: 10.1021/la304710k. Epub 2013 Jan 9.
Functional amyloid fibers termed curli contribute to bacterial adhesion and biofilm formation in Escherichia coli . We discovered that the nonionic surfactant Tween 20 inhibits biofilm formation by uropathogenic E. coli at the air-liquid interface, referred to as pellicle formation, and at the solid-liquid interface. At Tween 20 concentrations near and above the critical micelle concentration, the interfacial viscoelastic modulus is reduced to zero as cellular aggregates at the air-liquid interface are locally disconnected and eventually eliminated. Tween 20 does not inhibit the production of curli but prevents curli-integrated film formation. Our results support a model in which the hydrophobic curli fibers associated with bacteria near the air-liquid interface require access to the gas phase to formed strong physical entanglements and to form a network that can support shear stress.
功能型纤维蛋白被称为菌毛，有助于大肠杆菌的细菌黏附和生物膜的形成。我们发现，非离子表面活性剂吐温 20 可抑制尿路致病性大肠杆菌在气液界面（即菌膜形成）和固液界面的生物膜形成。在接近和超过临界胶束浓度的吐温 20 浓度下，界面黏弹性模量降至零，因为气液界面的细胞聚集体局部断开，最终被消除。吐温 20 并不抑制菌毛的产生，但可阻止菌毛整合膜的形成。我们的研究结果支持这样一种模型，即在气液界面附近的细菌上与菌毛相关的疏水性纤维需要进入气相，以形成强物理缠结，并形成一个可以承受剪切力的网络。
