Collaborative Research: Microbial Fuel Cell Optimization through Digital Microfluidic Electrochemistry in Single-Bacterial Drops

合作研究：通过单细菌液滴中的数字微流体电化学优化微生物燃料电池

• 批准号: 1605787
• 负责人: Susan Daniel
• 金额: $ 24.78万
• 依托单位: Cornell University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-08-01 至 2021-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1605787&HistoricalAwards=false
• 关键词: Collaborative; Research; Microbial; Fuel; Cell

Municipal wastewater treatment processes consume significant amounts of energy. However, the organic materials fed into the waste treatment process offer the potential for energy-positive waste water treatment if this waste organic material can be converted into energy. Many bacteria that grow in waste water can be harnessed to consume these organic contaminants to clean up the water and at the same time generate electrical current from their metabolism. These bacteria are bound within an electrode of a device called a microbial fuel cell to harvest this current as electrical power. To achieve maximum power output from microbial fuel cells, it must be determined how many species of bacteria, when organized into complex colonies known as biofilms, collaborate to convert organic matter into electricity. This project will study this collaborative metabolism within a novel miniaturized culture system capable of high-through analysis to accelerate the screening process. This miniature culture system will be capable of measuring metabolism of a single bacterial species, as well as in small mixed colonies of many bacteria, from a single drop of culture. This information will be used to determine how the electrical current produced and the organic matter consumed depends on bacterium type, as well as the potential synergy between many types of bacteria. The educational activities inspired by this project feature a hands-on teaching module for high school girls, who will build a simple microbial fuel cell to power a light-emitted diode (LED) or a digital watch. It is hoped this activity will illustrate to high school girls the potential of renewable green energy and biotechnology as exciting future career choices.The microbial fuel cell system components, which include electrodes, membranes, and bacteria, must be carefully engineered to achieve optimal power generation. This project will focus on genetic optimization of the bacteria within the electrode. This optimization is challenging given the interconnected manner in which wastewater bacteria grow. Towards this end, the proposed research has two primary objectives. The first objective is to develop a high-throughput digital microfluidic (DMF) platform for studying microbial fuel cell metabolism and electrical current evolution from single species of bacteria or small colonies of mixed bacteria. The second goal is to optimize the bacterial communities for high power density through high-throughput analysis of single bacterium electron transfer limitations. The DMF chip will be fabricated with droplet actuation electrodes, nanostructured electrochemical electrodes, and isolated on-chip microwell cell culture chambers. The droplet actuation electrode deposits a culture droplet into the microwell, and nanostructured electrodes within the culture microwell will enable the detection of single bacterium output current as well as measurement of specific cell culture contents using cyclic voltammetry. Bacteria known to consume organic matter in waste water and convert it into electrical current through microbioelectrochemical metabolic processes, including P. aeruginosa, Geobacter (G. sulfurreducens) and Shewanella (S. oneidensis) will first be studied as the model exoelectrogens in single species culture. By selectively increasing complexity and heterogeneity in the culture systems, beginning with isolated single species and moving to mixed bacterial colonies, a better understanding of the synergism among bacteria can be systematically determined. Through this study, it also is hoped that the DMF chip will become established as a new tool for studying electron transfer processes in bioelectrochemically-active bacteria.

市政废水处理过程消耗大量能量。 但是，如果可以将这些废物有机材料转化为能量，则供应废物处理过程中的有机材料为能量阳性废水处理提供了潜力。 可以利用许多在废水中生长的细菌，以消耗这些有机污染物来清理水，同时从其新陈代谢中产生电流。 这些细菌与称为微生物燃料电池的设备的电极结合，以收集该电流为电力。 为了实现微生物燃料电池的最大功率输出，必须确定有多少种细菌，当组织成被称为生物膜的复杂菌落时，可以协作将有机物转化为电力。 该项目将研究这种合作的代谢，在一个能够进行高直接分析的新型微型培养系统中，以加速筛查过程。 这种微型培养系统将能够从一滴培养物中测量单个细菌物种的代谢以及许多细菌的小菌落中的代谢。 这些信息将用于确定产生的电流和消耗的有机物如何取决于细菌类型，以及许多类型的细菌之间的潜在协同作用。 受此项目启发的教育活动为高中女生提供动手教学模块，这些模块将建立一个简单的微生物燃料电池，以为轻型二极管（LED）或数字手表供电。 希望这项活动能够为高中女生提供可再生绿色能源和生物技术的潜力，这是令人兴奋的未来职业选择。微生物燃料电池系统的组件，包括电极，膜和细菌，必须精心设计以实现最佳发电。该项目将集中于电极内细菌的遗传优化。 考虑到废水细菌的相互联系方式，这种优化是具有挑战性的。为此，拟议的研究有两个主要目标。第一个目标是开发一个高通量数字微流体（DMF）平台，用于研究微生物燃料电池代谢和从单个细菌或混合细菌的小菌落中的电流进化。第二个目标是通过对单细菌电子转移限制的高通量分析来优化细菌群落，以优化高功率密度。 DMF芯片将用液滴致动电极，纳米结构的电化学电极和分离的片上微孔细胞培养室制造。 液滴驱动电极沉积培养基液滴到微孔中，培养物中的纳米结构电极将实现使用环状伏安法的检测单细菌输出电流以及测量特定细胞培养物含量的测量。 已知可以在废水中食用有机物的细菌，并通过微生物电化学的代谢过程将其转化为电流，包括铜绿假单胞菌，Geobacter（G。sulfurreducens）和Shewanella（S. Oneidensis）（S. Oneidensis），将首先研究为单个物种培养物中的模型近代元素。 通过有选择地提高培养系统中的复杂性和异质性，从孤立的单个物种开始并转化为混合细菌菌落，可以系统地确定对细菌之间的协同作用的更好理解。 通过这项研究，还希望DMF芯片将成为研究生物电化学细菌中电子传递过程的新工具。