Enhancing and Redirecting Cyanobacterial Electron Flow (Bioelectricity Spotlight)

细胞内电子的运动是生命的基础，并驱动着细胞内发生的过程。对于光合生物来说，电子的运动可以由阳光提供动力，而对于所有生物来说，电子的运动可以由食物中化合物的代谢提供动力。电子可以在细胞内用于合成有用的化合物。一些电子可以离开细胞，产生电流，可以被收集并用作可再生能源。我们已经证明，这是可能的光合细菌（也称为“蓝绿藻”和“蓝藻”）。它们可以利用太阳光产生外部电流。我们已经成功地利用这些细菌的电流来驱动微处理器-在新闻媒体中被强调为“藻类动力计算”。我们的长期目标之一是找到增加光合细菌在细胞内外产生的电流的方法。然而，我们对决定有多少电子可用以及电子如何到达电池外部的因素知之甚少。这使得很难以一种有针对性的、理性的方式来改进这个过程。我们最近开发了一种筛选大量光合细菌细胞的方法，这些细胞具有增加电子可用性的遗传变化（突变）。这一令人兴奋的进步使我们能够找到具有改进的电子可用性的电池，而不必提前对该过程如何工作进行假设。我们将获得改进的细胞，然后确定负责的突变是什么。我们将测量改良细胞在细胞外产生电流的能力，以及在细胞内合成新化合物的能力。这对于利用这种“微生物电”的生物技术非常重要，也有助于我们回答有关限制电子运动的生物学问题。

The movement of electrons within cells is fundamental to life, and drives the processes that happen inside cells. For photosynthetic organisms, the movement of electrons can be powered by sunlight, and for all organisms it can be powered by the metabolism of compounds in food. The electrons can be used within cells in the synthesis of useful compounds. Some of the electrons can leave the cells, resulting in electric currents that can be harvested and used as a source of renewable energy. We have shown this is possible with photosynthetic bacteria (also known as 'blue-green algae' and 'cyanobacteria'). They can use sunlight to produce external electric current. We have succeeded in using the currents from these bacteria to drive a microprocessor - highlighted in the news media as 'algae-powered computing'. One of our long-term goals is to find ways to increase the electrical currents produced by photosynthetic bacteria, inside the cell or outside. However, we know little about what determines how many electrons are available, and how the electrons get to the outside of the cell. This makes it difficult to improve the process in a directed, rational way. We have recently developed a way of screening large numbers of photosynthetic bacterial cells for ones that have genetic changes (mutations) increasing electron availability. This exciting step forward allows us to find cells with improved electron availability without having to make assumptions in advance about how the process works. We will obtain improved cells, and then determine what the mutations responsible are. We will measure the ability of the improved cells to produce currents outside the cell, and to synthesis novel compounds inside the cell. This will be be important for biotechnological exploitation of this 'microbial electricity', and also help us to answer biological questions about what limits the movement of electrons.