Zhang Chao, Liao Qiang, Chen Rong, Zhu Xun
Key Laboratory of Low-grade Energy Utilization Technologies and Systems (Chongqing University), Ministry of Education, Chongqing 400030, China; Institute of Engineering Thermophysics, Chongqing University, Chongqing 400030, China.
Biochem Biophys Res Commun. 2015 Jun 12;461(4):671-6. doi: 10.1016/j.bbrc.2015.04.089. Epub 2015 Apr 24.
The formation of biofilm greatly affects the performance of biological reactors, which highly depends on bacterial swimming and attachment that usually takes place in liquid flow. Therefore, bacterial swimming and attachment on flat and circular surfaces with the consideration of flow was studied experimentally. Besides, a mathematical model comprehensively combining bacterial swimming and motion with flow is proposed for the simulation of bacterial locomotion and attachment in flow. Both experimental and theoretical results revealed that attached bacteria density increases with decreasing boundary layer thickness on both flat and circular surfaces, the consequence of which is inherently related to the competition between bacterial swimming and the non-slip motion with flow evaluated by the Péclet number. In the boundary layer, where the Péclet number is relatively higher, bacterial locomotion mainly depends on bacterial swimming. Thinner boundary layer promotes bacterial swimming towards the surface, leading to higher attachment density. To enhance the performance of biofilm reactors, it is effective to reduce the boundary layer thickness on desired surfaces.
生物膜的形成极大地影响生物反应器的性能，这高度依赖于通常在液流中发生的细菌游动和附着。因此，考虑到流动情况，对细菌在平面和圆形表面上的游动和附着进行了实验研究。此外，还提出了一个将细菌游动和运动与流动综合起来的数学模型，用于模拟流动中细菌的运动和附着。实验和理论结果均表明，在平面和圆形表面上，附着细菌的密度随着边界层厚度的减小而增加，其结果本质上与细菌游动和由佩克莱数评估的随流无滑移运动之间的竞争有关。在佩克莱数相对较高的边界层中，细菌运动主要取决于细菌游动。较薄的边界层促进细菌向表面游动，导致更高的附着密度。为提高生物膜反应器的性能，减小所需表面的边界层厚度是有效的。
