A study of metagenomics-informed biochemical functionality of microbial fuel cells using DDGS as a substrate

该提案涉及BBSRC的一项倡议，旨在提高干酒糟与可溶物（DDGS）的价值，DDGS是谷物转生物乙醇和威士忌生产的副产品。随着生物乙醇生产的发展，英国的DDGS将变得越来越丰富。微生物燃料电池（MFC）是一种含有微生物厌氧培养物的装置，能够直接将化学能转化为电能。典型的微生物燃料电池由阳极和阴极隔室组成，所述阳极和阴极隔室由阳离子（带正电荷的离子）特异性膜隔开。在阳极室中，营养物质被微生物氧化，产生电子和质子。电子通过外部电路转移到阴极室，而质子通过膜转移到阴极室。电子和质子在阴极室中消耗，与氧气结合形成水。我们将开发一种微生物燃料电池，该电池将在干燥和用作动物饲料之前处理DDGS。MFC将产生电力（以减少生物精炼厂的消耗）并提高动物饲料产品的蛋白质含量。添加到MFC中的微生物的种类将通过在一系列条件下分析存在于整个微生物群体中的所有基因（宏基因组学）并使用计算机模拟来确定，所述计算机模拟突出了最重要的基因以实现MFC的期望功能。通过为微生物提供营养物作为实现所需特征的奖励，将进一步微调种群组成，迫使其进化到最有效的物种分布。

This proposal addresses a BBSRC initiative that aims to enhance the value of Dried Distillers Grains with Solubles (DDGS), a byproduct of grain-to-bioethanol and whisky production. DDGS will become increasingly abundant in the UK as bioethanol production develops. It is currently mainly used as a cattle feed but there is also interest in developing it as an industrial feedstockA microbial fuel cell (MFC) is a device that contains an anerobic culture of microorgnaisms, capable of directly converting chemical energy to electrical energy. A typical microbial fuel cell consists of anode and cathode compartments separated by a cation (positively charged ion) specific membrane. In the anode compartment, nutrients are oxidized by microorganisms, generating electrons and protons. Electrons are transferred to the cathode compartment through an external electric circuit, while protons are transferred to the cathode compartment through the membrane. Electrons and protons are consumed in the cathode compartment, combining with oxygen to form water.We will develop a microbial fuel cell that will process DDGS prior to drying and use as an animal feed. The MFC will generate electricity (to reduce consumption by the biorefinery) and enhance the protein content of the animal feed product. The species of micro-organisms added to the MFC will be determined by analysing all of the genes present in whole populations of micro-organisms (metagenomics) under a range of conditions and using a computer simulation which highlights the most important genes to carry out the desired functions of the MFC. The population composition will be further fine-tuned by feeding the microbes with nutrients as rewards for achieving the desired characteristics, forcing it to evolve to the most effective distribution of species.