Li Xiaobo, Song Yanqing, Glidle Andrew, Smith Cindy, Sloan William, Cusack Maggie, Yin Huabing
James Watt School of Engineering, Advanced Research Centre (ARC), University of Glasgow, Chapel Lane, Glasgow G11 6EW, UK.
Munster Technological University, Rossa Avenue, Bishopstown, Cork, T12 P928, Ireland.
Lab Chip. 2025 Jan 28;25(3):343-353. doi: 10.1039/d4lc00892h.
Microbial chemotaxis plays a key role in a diversity of biological and ecological processes. Although microfluidics-based assays have been applied to investigate bacterial chemotaxis, retrieving chemotactic cells off-chip based on their dynamic chemotactic responses remains limited. Here, we present a simple three-dimensional microfluidic platform capable of programmable delivery of solutions, maintaining static, stable gradients for over 20 hours, followed by active sorting and retrieval of bacteria based on their chemotactic phenotypes. Using this platform, we revealed the swimming features of individual cells in response to chemoattractant and observed rapid bacterial adaptation to the gradients. Furthermore, the robust performance of the platform allowed us to investigate complex natural microbial communities. Exemplified by sorting bacteria towards soluble cellulose and lignin compounds, we found only a small percentage (<20%) of chemotactic bacteria from a leaf mould microbiota exhibited cellulolytic or lignin-degradation abilities. These findings highlight that chemotaxis does not always align with degradation abilities. Interestingly, a new strain was discovered with substantial cellulose degradation capabilities. These results illustrate the strong potential of this microfluidic platform for investigating broad processes involving bacterial chemotaxis and for discovering functional microbes.
微生物趋化性在多种生物和生态过程中起着关键作用。尽管基于微流控的分析方法已被用于研究细菌趋化性，但基于其动态趋化反应在芯片外检索趋化细胞仍然有限。在这里，我们展示了一个简单的三维微流控平台，该平台能够可编程地输送溶液，保持静态、稳定的梯度超过20小时，随后基于细菌的趋化表型进行主动分选和检索。使用这个平台，我们揭示了单个细胞对化学引诱剂的游动特征，并观察到细菌对梯度的快速适应。此外，该平台的强大性能使我们能够研究复杂的天然微生物群落。以将细菌分选到可溶性纤维素和木质素化合物为例，我们发现来自叶霉菌微生物群的趋化细菌中只有一小部分（<20%）表现出纤维素分解或木质素降解能力。这些发现突出表明趋化性并不总是与降解能力一致。有趣的是，发现了一种具有大量纤维素降解能力的新菌株。这些结果说明了这个微流控平台在研究涉及细菌趋化性的广泛过程和发现功能微生物方面的强大潜力。
