A synthetic biology approach to optimisation of microbial fuel cell electricity production

优化微生物燃料电池发电的合成生物学方法

• 批准号: EP/J003964/2
• 负责人: Susan Rosser
• 金额: $ 91.87万
• 依托单位: University of Edinburgh
• 依托单位国家: 英国
• 项目类别: Fellowship
• 财政年份: 2013
• 资助国家: 英国
• 起止时间: 2013 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FJ003964%2F2
• 关键词: synthetic; biology; approach; optimisation; microbial

The depletion of fossil fuel reserves, global warming, energy security and the need for clean, cheap fuels has made developing sources of renewable energy a global research priority. Microbial Fuel Cells (MFCs) have the potential to generate renewable electricity from a vast array of carbon sources such as waste-water, agricultural by-products and industrial pollutants. In MFCs electrons from microbial metabolism flow from the bacteria toward an anode then on through an external circuit finally converting oxygen into water at the cathode closing the cycle. MFCs have the advantage that they can vary from micro fluidic to waste water treatment plant scale depending on the desired application. A great deal of work has been published on optimizing microbial fuel cell electricity generation by exploring the range of carbon sources for metabolism, modifying the design and electrode composition of the fuel cell and examining the microbial community composition and structure occurring in MFCs. However there are still many obstacles that need to be overcome before this technology can be effectively put to use. The optimization of MFC systems is a highly multidisciplinary area of research and two complementary areas of work are required - firstly to design more efficient hardware for the cells by traditional engineering and secondly to understand and improve the interaction and electron transport between microbes and electrode via biological engineering. One of the most important engineering challenges in MFC development is the efficient electron transfer from the bacteria to the anode. To date three possible methods of transferring electrons from bacterial cells to the electrode have been identified - directly via cell surface cytochromes (e.g. Shewanella spp), via pili acting as nanowires (e.g. Geobacter spp) or via the production of soluble electron mediator compounds (e.g. Pseudomonas sp phenazine production). Fundamental to cell contact with the anode, electron transfer and thus the functioning of the MFC is the formation of specialized biofilms on the electrode surface. It has been shown that the power output of MFCs and that the power density was directly dependent on biofilm growth and composition. The objective of this proposal is to use a synthetic biology approach to reengineer bacteria to predictably and efficiently generate and transfer electrons to microbial fuel cell electrodes resulting in a highly versatile, reliable and sustainable energy sources. Synthetic biology aims to use a rigorous engineering approach to design and build new standardized biological parts, devices and systems or to reconfigure existing ones to be more efficient or to carry out new functions and has the potential to revolutionise how we conceptualise and approach the engineering of biological systems. This project aims to -a) Create a synthetic biology toolbox of biological parts and devices for the easy engineering of electrogenic microbial strains and the construction of genetic circuits for the enhanced production of nanowire pili, surface active cytochromes and production of electron mediator compounds. b) Engineer cells to have enhanced electron transfer capabilities. c) Investigate the structure and composition electrode biofilms formed by the engineered bacteria individually, in combination with each other and their prevalence and persistence when introduced to a naturally occurring anodic biofilm derived from a variety of waste-waters. d) The versatility of carbon metabolism in the bacteria will be engineered to expand the range and efficiency of utilising pollutants as carbon sources for electricity generating metabolism closing the waste disposal energy generation loop which would be of obvious and enormous benefit to a wide range of industries.

化石燃料储量的枯竭、全球变暖、能源安全以及对清洁廉价燃料的需求，使开发可再生能源成为全球研究的优先事项。微生物燃料电池（MFC）具有从大量碳源（如废水、农业副产品和工业污染物）中产生可再生电力的潜力。在MFC中，来自微生物代谢的电子从细菌流向阳极，然后通过外部电路，最终在阴极将氧气转化为水，从而关闭循环。MFC的优点在于，它们可以根据所需的应用从微流体到废水处理厂规模变化。通过探索代谢碳源的范围、修改燃料电池的设计和电极组成以及检查MFC中发生的微生物群落组成和结构，已经发表了大量关于优化微生物燃料电池发电的工作。然而，在这项技术能够有效地投入使用之前，仍然有许多障碍需要克服。MFC系统的优化是一个高度多学科的研究领域，需要两个互补的工作领域-首先通过传统工程为细胞设计更有效的硬件，其次通过生物工程理解和改善微生物与电极之间的相互作用和电子传输。MFC开发中最重要的工程挑战之一是从细菌到阳极的有效电子转移。迄今为止，已经确定了将电子从细菌细胞转移到电极的三种可能的方法-直接经由细胞表面细胞色素（例如希瓦氏菌属（Shewanella spp））、经由充当纳米线的皮利（例如Geelopsis spp））或经由可溶性电子介体化合物的产生（例如假单胞菌属（Pseudomonassp）吩嗪产生）。细胞与阳极接触、电子转移以及因此MFC的功能的基础是在电极表面上形成专门的生物膜。已经表明，MFC的功率输出和功率密度直接取决于生物膜的生长和组成。该提案的目的是使用合成生物学方法来重新设计细菌，以可预测和有效地产生电子并将电子转移到微生物燃料电池电极，从而产生高度通用，可靠和可持续的能源。合成生物学旨在使用严格的工程方法来设计和构建新的标准化生物部件，设备和系统，或重新配置现有的生物部件，设备和系统以提高效率或执行新的功能，并有可能彻底改变我们如何概念化和接近生物系统工程。该项目的目标是：（a）创建一个生物部件和装置的合成生物学工具箱，以便于对产电微生物菌株进行工程改造，并构建基因电路，以提高纳米线皮利、表面活性细胞色素的生产，并生产电子介体化合物。B）工程化细胞以具有增强的电子转移能力。c）研究由工程化细菌单独地、彼此组合地形成的电极生物膜的结构和组成，以及当引入到源自各种废水的天然存在的阳极生物膜时它们的流行和持久性。d）将对细菌中碳代谢的多功能性进行工程改造，以扩大利用污染物作为发电代谢碳源的范围和效率，从而关闭废物处理能量产生回路，这将对广泛的行业产生明显和巨大的好处。