Improving photosynthesis for biofuel production

在全球范围内，氧合光合作用被提出用于燃料生产。要使这一过程可行，需要有较高的太阳能转化率。这一要求与光合作用效率有关，即将太阳能转化为有机物质的效率。蓝藻是理想的生物燃料原料，因为它们在非农业和边际土地上生长，并能够在微咸水和海水中茁壮成长。然而，尽管它们理论上的最大能量转换效率估计为8-10%，但报道的最好的持续效率为1-2%。我们将研究蓝藻捕光以提高光合作用效率。我们将探索二氧化碳如何与太阳能耦合，因为平衡源/汇能量是提高光合作用效率的一种策略。我们开发了识别二氧化碳结合蛋白的技术(自然通信(2018年)9：3092DOI：10.1038/s41467018-05475-z)。这项技术可以识别功能蛋白质(Science Advents(2021)7：eabi5507)。我们在捕光复合体(Natural Communications(2022)DOI：10.1038/s41467-022-32925-6)中鉴定出了一种二氧化碳结合蛋白。我们将研究二氧化碳结合对采光的影响。我们建议操纵这一过程来改变源/库能量，提高光合作用效率。今年1.化学蛋白质组学和13C-核磁共振证实蛋白质与二氧化碳的结合。量子产额测量和超快飞秒光谱研究二氧化碳对光收集的影响。第2年：使用CRISPR：Cpf1突变法产生突变蓝藻菌株。使用稳态和时间分辨荧光光谱学研究二氧化碳对天然藻胆体和整个生物体采光的影响。3-4年级。研究利用目标2中确定的突变对光收集进行工程改造的生产菌株的生物乙醇产量。

Oxygenic photosynthesis is proposed for fuel production on a global scale. A high solar energy conversion rate is needed to make the process feasible. This requirement is linked to the photosynthetic efficiency, i.e., the conversion efficiency of solar energy to organic material.The cyanobacteria are desirable biofuel feedstocks due to their growth on non-agricultural and marginal lands and ability to thrive in brackish and marine waters. However, although their theoretical maximum efficiency of energy conversion is estimated as 8-10%, the best-sustained efficiencies reported are 1-2%.We will investigate cyanobacterial light-harvesting to enhance photosynthetic efficiency. We will explore how carbon dioxide couples to solar energy, as balancing source/sink energies is a strategy for improving photosynthetic efficiency.We have developed technology for identifying CO2-binding proteins (Nature Communications (2018) 9:3092 DOI: 10.1038/s41467-018-05475-z). This technology can identify functional proteins (Science Advances (2021) 7:eabi5507).We have identified a CO2-binding protein in the light-harvesting complex (Nature Communcations (2022) DOI: 10.1038/s41467-022-32925-6). We will investigate the impact of CO2-binding on light-harvesting. We propose manipulating this process to alter source/sink energies and improve photosynthetic efficiency.Year 1. Chemical proteomics and 13C-NMR to demonstrate protein CO2-binding. Quantum yield measurements and ultrafast femtosecond spectroscopy to investigate the influence of CO2 on light-harvesting. Year 2. Generate mutant cyanobacterial strains using CRISPR:Cpf1 mutagenesis. Use steady-state and time-resolved fluorescence spectroscopy to investigate the impact of CO2 on light-harvesting in native phycobilisomes and whole organisms. Year 3-4. Investigate bio-ethanol yield in producing strains in which light-harvesting has been engineered with the mutations identified in Objective 2.