Kim Beum Jun, Chu Injun, Jusuf Sebastian, Kuo Tiffany, TerAvest Michaela A, Angenent Largus T, Wu Mingming
Department of Biological and Environmental Engineering, Cornell University Ithaca, NY, USA.
School of Chemical and Biomolecular Engineering, Cornell University Ithaca, NY, USA.
Front Microbiol. 2016 Sep 20;7:1438. doi: 10.3389/fmicb.2016.01438. eCollection 2016.
is a model bacterial strain for studies of bioelectrochemical systems (BESs). It has two extracellular electron transfer pathways: (1) shuttling electrons an excreted mediator riboflavin; and (2) direct contact between the -type cytochromes at the cell membrane and the electrode. Despite the extensive use of in BESs such as microbial fuel cells and biosensors, many basic microbiology questions about in the context of BES remain unanswered. Here, we present studies of motility and chemotaxis of under well controlled concentration gradients of two electron acceptors, oxygen and oxidized form of riboflavin (flavin+), using a newly developed microfluidic platform. Experimental results demonstrate that either oxygen or flavin+ is a chemoattractant to The chemotactic tendency of in a flavin+ concentration gradient is significantly enhanced in an anaerobic in contrast to an aerobic condition. Furthermore, either a low oxygen tension or a high flavin+ concentration considerably enhances the speed of This work presents a robust microfluidic platform for generating oxygen and/or flavin+ gradients in an aqueous environment, and demonstrates that two important electron acceptors, oxygen and oxidized riboflavin, cooperatively regulate migration patterns. The microfluidic tools presented as well as the knowledge gained in this work can be used to guide the future design of BESs for efficient electron production.
是用于生物电化学系统（BESs）研究的典型细菌菌株。它有两条细胞外电子转移途径：（1）通过分泌的介质核黄素穿梭电子；（2）细胞膜上的 - 型细胞色素与电极直接接触。尽管 在微生物燃料电池和生物传感器等BESs中被广泛应用，但在BESs背景下关于 的许多基础微生物学问题仍未得到解答。在此，我们使用新开发的微流控平台，对 在两种电子受体（氧气和核黄素氧化形式（黄素 +））的浓度梯度得到良好控制的条件下的运动性和趋化性进行了研究。实验结果表明，氧气或黄素 + 对 都是化学引诱剂。与有氧条件相比，在厌氧条件下， 在黄素 + 浓度梯度中的趋化倾向显著增强。此外，低氧张力或高黄素 + 浓度都能显著提高 的速度。这项工作展示了一个用于在水性环境中产生氧气和/或黄素 + 梯度的强大微流控平台，并证明了两种重要的电子受体，氧气和氧化核黄素，协同调节 迁移模式。本文展示的微流控工具以及在这项工作中获得的知识可用于指导未来高效电子生产的BESs设计。
