Single Nanoparticle Tracking Reveals Efficient Long-Distance Undercurrent Transport in Upper Fluid of Bacterial Swarms
Single Nanoparticle Tracking Reveals Efficient Long-Distance Undercurrent Transport in Upper Fluid of Bacterial Swarms
复制标题
单纳米粒子追踪揭示了细菌群上层流体的有效长距离暗流传输
DOI：
10.1016/j.isci.2019.11.012
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发表时间：
2019-12-20
期刊：
影响因子：
5.8
通讯作者：
He, Yan
中科院分区：
文献类型：
--
作者：
Feng, Jingjing;Zhang, Zexin;He, Yan
鞭毛细菌在浸泡在一层薄薄的粘性“蜂群流体”中的琼脂表面上以漩涡的方式集体移动，但这种流体在调节细菌群体合作中的作用尚不清楚。在此，我们使用金纳米棒（aunr）作为单粒子示踪剂来探索群体流体的时空结构。单个aunr在一个类似于2 μ m的平面上移动，在没有细菌运动干扰的情况下高速移动很长一段距离。在活动细胞的局部聚类和去聚类过程中，细菌周围的小涡的集体混合提升和运输颗粒。它们的运动符合列维行走模型，揭示了蜂群上方有效的流体流动。这些流动为长距离物质运输提供了无障碍的高速公路，使成群的细菌能够进行种群水平的通信，并暗示了流体阶段在大规模协同作用出现中的重要作用。
Flagellated bacteria move collectively in a swirling pattern on agar surfaces immersed in a thin layer of viscous "swarm fluid,'' but the role of this fluid in mediating the cooperation of the bacterial population is notwell understood. Herein, we use gold nanorods (AuNRs) as single particle tracers to explore the spatiotemporal structure of the swarm fluid. Individual AuNRs are moving in a plane of similar to 2 mu m above swarms, traveling for long distances in high speed without interferences from bacterial movements. The particles are lifted and transported by collective mixing of small vortices around bacteria during localized clustering and de-clustering of motile cells. Their motions fit the Levy walk model, revealing efficient fluidic flows above the swarms. These flows provide obstacle-free highways for long-range material transportations, allow swarming bacteria to perform population-level communications, and imply the essential role of the fluid phase on the emergence of large-scale synergy.