Visualising electrogenesis by photosynthetic micro-organisms

博士项目战略主题：可再生资源和清洁增长的生物科学光合作用是能量进入生物体和生态系统的主要手段。然而，依靠太阳能进行地窖过程的生物体（光养生物）牺牲了整体太阳能到生物量的转换，而有利于其他生存策略。在这种能量损失的背后有许多已知的物理机制，但最不了解的是光合微生物的高能电子载体的明显输出，这种现象被称为（外）产电。了解外生电在基础层面上很重要，可以更好地了解维持地球生命的生物过程。此外，了解这一途径对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装置具有影响。生物光伏装置利用光合微生物从水和阳光中产生电力。与传统的光子学不同，生物光子学不依赖于昂贵的或提取的材料，然而由于电池和电极之间的低效“布线”，它们目前具有有限的功率输出。类似地，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，这是全球远离化石燃料的过渡所急需的技术。这些技术依赖于电子在电极和细胞之间的传递，更好地理解这一过程对于克服现有技术的局限性至关重要。在细胞外电子传递的研究中，电化学技术因其能够探测电子传递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生物光伏应用系统中是强大的，并且可以用于推断电子转移机制到亚秒级的时间分辨率。然而，它是有限的，在其能力，以提供视觉信息的过程中涉及的电子转移或解决这些过程的空间。荧光显微镜技术非常适合解决这一差距，因为它们可以提供越来越高的时间和空间分辨率的亚细胞系统的视觉信息。该项目将专注于电荷转移过程中光合生物膜-电极界面的可视化和表征，探索使用化学生物学和电化学方法，如原位共聚焦荧光，全内反射荧光和拉曼显微术。这将通过使用超分辨率显微镜技术，如结构照明显微镜来补充。其目的将是获得一个更好的理解光诱导电流产生的光合生物膜的生物学现象，并最终合理地提高生物膜和电极之间的“布线”。该项目将是高度跨学科的，将涉及合成（染料和电极材料）和生物系统（蛋白质，亚细胞成分和生物工程细胞）的化学和生物物理特性。

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).