Fundamental and applied studies of biological light-harvesting systems

我的研究集中在微生物上，这些微生物利用生物光系统或光合反应中心（RC）中结合的特殊蛋白质和色素，捕捉太阳光并将其能量转化为电流。我的方法范围从寻找新物种到具有新生物物理特性的工程蛋白质，以及在将阳光转化为电能的生物光伏设备中的应用。加拿大致力于减少碳排放（www.ec.gc.ca），在非核、碳中性的电力能源（太阳能、风能、生物质能、水）中，太阳能的潜力最大（比其他三种能源的总和大10倍）。由于我们对生物光系统的认识和新的基因工程方法的提高，生物光系统在光伏发电中的应用已经成为可能，但我们仍然需要回答关于蛋白质中光子和电路的设计和创造的许多问题，以充分利用这些系统的潜力。******提出的研究有两个目的：1)利用自然样品发现和表征具有新特性的生物光系统；2)利用合成生物学，创造新的电流通路，进出和穿过作为电路一部分的蛋白质。每个目标都将受益于对方产生的新信息。* * * * * * 1。为了获得自然样本，我们将：1)从自然环境中培育新物种；Ii)从宏基因组（从环境中收集的遗传物质）档案中提取基因。我们将利用我们获得的基因在我们的合成生物系统中创造活跃的光系统，该系统以在中等温度（20-45摄氏度）下生长的光合细菌球形红杆菌为基础。具有新的物理化学性质的光系统将被用于设计生物光伏器件。目标是使用来自嗜热细菌的基因，因为它们的蛋白质应该耐受高温（50-70摄氏度），这种高温可能出现在太阳能应用中，比如屋顶上。* * * * * * 2。我们将开始创造新的电通路与R. sphaeroides的RC，无论是单独或作为一个共复合体由光收集色素-蛋白质复合体包围，在某些情况下提供耐热性。我们将改变蛋白质中特定位点的氨基酸，以阻断自然电子传递途径，并将高压电流从RC转移到连接电路的电极上。我们将测试色氨酸和酪氨酸残基是否可以用于在兴奋的光色素和外部电路之间创建新的电子隧道通路。最初的目标是创造新的途径，以提取电压增加的电流，利用球形圆叶藻蛋白。后来的工作将是在Aim 1中发现的嗜热细菌的光系统。******我们的工作将创造新的知识，推进光伏技术，并为未来的研究和技术开发职业培养学生。

My research centres on microbes that capture solar light and convert its energy to electrical current, using special proteins and pigments combined in a biological photosystem or photosynthetic reaction centre (RC). My approach ranges from finding new species to engineering proteins with new biophysical properties, and applications in biophotovoltaic devices that convert sunlight to electricity. Canada is committed to reducing carbon emissions (www.ec.gc.ca) and of the non-nuclear, carbon-neutral electrical energy sources (solar, wind, biomass, water) solar has the greatest potential (order of 10-fold greater than the other three combined). The use of biological photosystems in photovoltaics has become possible due to our improved knowledge of these systems and new gene engineering methods, but we still need to answer many questions about the design and creation of photon and electrical circuits in proteins, to make full use of the potential of these systems. ******The proposed research has two Aims: 1) to discover and characterize biological photosystems with new properties, using natural samples; 2) to create novel electrical pathways into, out of, and through proteins that are part of an electrical circuit, using synthetic biology. Each aim will benefit from new information generated in the other. ******1. To get natural samples we will: i) cultivate new species from natural environments; ii) extract genes from metagenome (genetic material collected from the environment) archives. We will use the genes we get to create active photosystems in our synthetic biology system, based on the photosynthetic bacterium Rhodobacter sphaeroides, which grows at moderate temperatures (20-45 C). Photosystems that have new physicochemical properties will be used to design biophotovoltaic devices. The goal is to use genes from thermophilic (heat loving) bacteria as their proteins should tolerate high temperatures (50-70 C) that might occur in solar energy applications such as on rooftops. ******2. We will begin creating new electrical pathways with the RC of R. sphaeroides, both alone and as a co-complex encircled by a light-harvesting pigment-protein complex, which in some cases provides heat tolerance. We will change amino acids at specific sites in the protein to block the natural electron transfer pathway, and to divert high-voltage electricity from the RC to an electrode connected to a circuit. We will test if tryptophan and tyrosine residues may be used to create novel electron-tunnelling pathways between excited photopigments and an external electrical circuit. The initial goal is to create new pathways that extract electrical current of increased voltage using R. sphaeroides proteins. Later work will be on photosystems from thermophilic bacteria found in Aim 1.******Our work will create new knowledge, advance photovoltaic technology, and train students for future careers in research and technology development.