Advancing Microbial Electrochemistry: Biophysical Characterisation of the Electron-Transfer Interactome in S. oneidensis MR-1

有关化石燃料储量减少和对燃料安全的担忧的报道经常成为新闻头条。不断上涨的燃料成本每天都在提醒我们，能源需求不断增长的全球社会所面临的挑战。在这种情况下，也许令人惊讶的是，可供我们使用的能源供应，即阳光、风、波浪和生物有机产品，在很大程度上仍然是未开发的资源。目前，我们需要大量的能源来处理废水和污水。后者是由细菌完成的，细菌消耗并因此从我们的污水中去除有机废物，并将其转化为清洁水和二氧化碳。细菌从这个过程中提取能量，就像我们从食物中提取能量一样。然而，在一个非常有趣的过程中，一些细菌在消化过程中会分泌出电。这种生物电可以通过将这些细菌与电极连接来收集。最近已经发现，通过对电极施加适当的电压，电流也可以逆转。通过这种方式，电子被推入细菌，它们可以驱动酶的活动，从低价值、丰富的分子（如二氧化碳）中制造昂贵的石油衍生化学品和燃料。上面的例子说明了细菌电化学如何提供多种途径来支持可持续的未来。然而，要完全实现这些有前途的技术，需要电流在细菌中的蛋白质网络中以最佳方式流动，并被输送到适当的酶。在家里也是如此，当你想看电影时，电应该被引导到你面前的电视机上，而不是另一个房间或隔壁的电视机上。了解电路，开关和保险丝盒确保所需的电流以安全的方式从发电站到你的电视。在这里，我们的目的是阐明细菌相当于我们周围的电网。我们将确定一种叫做希瓦氏菌（Shewanella oneidensis）的细菌内部的蛋白质网络是如何调节电流的，希瓦氏菌是开发细菌电化学的“实验室老鼠”。

Reports concerning dwindling reserves of fossil fuels and concerns over fuel security are frequent news headlines. The rising costs of fuel are a daily reminder of the challenges faced by a global society with ever increasing energy demands. In this context it is perhaps surprising that the energy supplies available to us, namely, sunlight, winds, waves and bio-organic produce, remain largely untapped resources. A significant amount of our energy demand is currently needed to process our waste water and sewage. The latter is done by bacteria, which consume and thereby remove organic waste materials from our sewage and convert it to clean water and carbon dioxide. The bacteria extract energy out of this process in the same way we extract energy out of the food we eat. However, in a very intriguing process some bacteria excrete electricity as a result of their digestive processes. This bio-electricity can be harvested by interfacing these bacteria with electrodes. Recently it has been discovered that by applying an appropriate voltage to the electrode the flow of electricity can also be reversed. In this way electrons are pushed into the bacteria and they can drive the activities of enzymes to make otherwise costly, petroleum derived chemicals and fuels from low-value, abundant molecules such as carbon dioxide. The examples above illustrate how bacterial electrochemistry offers multiple routes to support a sustainable future. However, full realisation of these promising technologies requires electricity to flow optimally across a network of proteins in the bacteria and be delivered to the appropriate enzyme(s). In much the same way at home, electricity should be directed to the TV in front of you rather than one in another room, or next door when you wish to watch a film. Well understood circuitry, switches and fuse boxes ensure the desired flow of electricity occurs in a safe manner from the power station to your TV. Here we aim to elucidate the bacterial equivalents of the electrical grid that surrounds us. We will establish how the flow of electricity is regulated by the network of proteins within a bacterium called Shewanella oneidensis that is the 'lab rat' for developing bacterial electrochemistry.