Visualising electrogenesis by photosynthetic micro-organisms

PHD项目战略主题：生物科学促进可再生资源和清洁增长光合作用是能量进入生物有机体和生态系统的主要手段。然而，依赖太阳能进行地窖过程(光养生物)的生物牺牲了整个太阳能到生物量的转换，转而支持其他生存策略。这种能量损失背后有许多已知的物理机制，但最不为人所知的机制之一是光合作用微生物表面输出高能电子载体，这种现象被称为(外生)电作用。要更好地理解维持地球上生命的生物过程，从根本上理解外电发生是很重要的。此外，了解这一途径对于智能设计用于太阳能发电和太阳能燃料生产的半人工光合作用设备具有重要意义。生物光伏设备利用光合作用微生物从水和阳光中产生电力。与传统的光伏不同，生物光伏不依赖昂贵的或提取的材料，但由于电池和电极之间的低效“接线”，目前它们的功率输出有限。同样，光微生物燃料电池利用光养微生物从阳光、水和其他简单的化学物质中产生液体燃料，这是全球摆脱化石燃料的过程中非常需要的一项技术。这些技术依赖于电极和细胞之间的电子转移，而更好地了解这一过程对于克服它们的电流限制是至关重要的。在细胞外电子转移的研究中，电化学技术因其能够探测电子转移事件的热力学和动力学而受到青睐。电化学已被证明在研究用于生物光伏应用的系统方面是强大的，并可用于推断电子转移的机制，以达到亚秒级的时间分辨率。然而，它在提供有关电子转移过程的可视信息或在空间上解决这些过程方面的能力是有限的。荧光显微镜技术非常适合于解决这一问题，因为它们可以以越来越高的时间和空间分辨率提供关于亚细胞系统的可视信息。该项目将专注于电荷转移过程中光合作用生物膜-电极界面的可视化和表征，探索化学生物学和电化学方法的使用，如原位共聚焦荧光、全内反射荧光和拉曼显微镜。这将通过使用超分辨率显微镜技术来补充，例如结构照明显微镜。其目的是为了更好地理解光合作用生物膜产生光诱导电流这一模糊的生物学现象，并最终合理地加强生物膜和电极之间的“连接”。该项目将是高度跨学科的，将涉及合成系统(染料和电极材料)和生物系统(蛋白质、亚细胞组件和生物工程细胞)的化学和生物物理特征。

PhD project strategic theme: Biosciences for renewable resources and clean growthPhotosynthesis is the primary means by which energy enters living organisms and ecosystems. However, organisms that rely on solar energy to carry out cellar processes (phototrophs) sacrifice overall solar-to-biomass conversion in favour of other survival strategies. There are many physical known mechanisms behind this energy loss, but one of the least well understood is the apparent export of energetic electron carriers out of photosynthetic microorganisms, a phenomenon referred to as (exo)electrogenesis. Understanding exoelectrogenesis is important at a fundamental level, to better understand the biological process that sustains life on Earth. Additionally, understanding this pathway has ramifications for the intelligent design of semi-artificial photosynthetic devices for solar electricity and solar fuel production. Biophotovoltaic devices employ photosynthetic microorganisms to produce electricity from water and sunlight. Unlike conventional photovoltaics, biophotovoltaics do not rely on expensive or extracted materials, however they currently have a limited power output due to inefficient "wiring" between cell and electrode. Similarly, photomicrobial fuel cells employ phototrophic microorganisms to generate liquid fuels from sunlight, water and other simple chemicals, a technology that is much needed in the global transition away from fossil fuels. These technologies rely on the transfer of electrons between electrodes and cells, and a better understanding of this process is essential to overcoming their current limitations.In the study of extracellular electron transfer, electrochemical techniques are favoured for their ability to probe the thermodynamics and kinetics of electron transfer events. Electrochemistry has proven powerful in studying systems intended for biophotovoltaic application and can be used to infer mechanism of electron transfer to a sub-second temporal resolution. However, it is limited in its ability to provide visual information on the processes involved in electron transfer or resolve these processes spatially. Fluorescence microscopy techniques are well suited to addressing this gap, as they can provide visual information on subcellular systems at increasingly high temporal and spatial resolution.The project will focus on the visualisation and characterisation of the photosynthetic biofilm-electrode interface during charge transfer processes, exploring the use of chemical biology and electrochemical methods such as in situ confocal fluorescence, total internal reflection fluorescence and Raman microscopy. This will be complemented by the use of super resolution microscopy techniques such as structured illumination microscopy. The aim will be to gain a better understanding of the poorly defined biological phenomenon of light-induced current generation by photosynthetic biofilms, and ultimately to rationally enhance the 'wiring' between the biofilm and the electrode. The project will be highly interdisciplinary and will involve chemical and biophysical characterisations of both synthetic (dyes and electrode materials) and biological systems (proteins, sub-cellular components and bioengineered cells).