Unlocking the Promise of Bacterial Electrogenicity

Suny At Binghamton, Binghamton NY

Investigators

Abstract

Microbial electron transfer capability, or 'electrogenicity' creates a plethora of concepts and potential applications that offer environmentally sustainable advances in the fields of biofuels, wastewater treatment, bioremediation, desalination, and biosensing. Despite its vast potential and remarkable research efforts, bacterial electrogenicity is arguably the most underdeveloped technology used for those applications. Severe limitations are placed on the intrinsic energy and electron transfer processes of naturally occurring microorganisms. Significant boosts in this technology can be achieved with the growth of synthetic biology that manipulates microbial electron transfer pathways and improves their electrogenic potential. What is needed is a high-throughput, rapid and highly sensitive test array for investigating the electrogenicity of hundreds of newly discovered, genetically engineered bacterial species. This is by no means a simple challenge, as accurate and parallel quantitative measurements of bacterial electrogenicity require a long measurement time (10's of days), continuous introduction of organic fuels (10's of milliliters), complex device architectures, and labor-intensive operation. The overall objective of this NSF proposal is to create the ability to achieve rapid (<5 min.), sensitive (>10-fold improvement), and high-throughput (>384 wells) characterization of bacterial electrogenicity from a single drop of culture (<1 microliter). Findings will first be disseminated within the discipline through local and international conferences and journal publications; then they will be distributed through educational venues maximizing the project's reach and impact. The purpose of this project is to investigate an exciting range of possibilities which support the goal of fusing microbial fuel cell technology with 'papertronics' the emerging field of paper-based electronics. An optimized combination can create a new kind of scalable, high-throughput sensing array for simple, sensitive, and rapid quantification of microbial electrogenicity. This research will use paper as a device substrate that inherently produces favorable conditions for easy, rapid, and sensitive control of a microbial liquid sample. The high-throughput array will be batch-fabricated through printing-only processes of 3-D capillary-driven sensors on a single sheet of paper. Full integration of a high-performance microbial fuel cell on paper can be achieved by improving the microbial electron exchange with the electrodes in an engineered conductive paper reservoir and reducing cathodic overpotential using a solid electron acceptor on paper. Furthermore, the intrinsic capillary force of the paper and the increased capacity from the engineered reservoir will allow for rapid adsorption of the bacterial sample and promote immediate microbial cell attachment to the electrode, leading to instant power generation with only a small amount of the liquid. The immediate potential benefits of the proposed research are that (i) it will create the first paper-based approach for large-scale biosensing applications, incorporating fluidic and electronic components, which will augment early work in papertronics, (ii) it will provide a high-throughput parallel analysis of hundreds of types of bacterial electrogenicity with in-depth understanding of extracellular electron transfer pathways that are relevant to their genetic engineering, and (iii) it will catalyze energy and environment-related research, helping to expand scientists' understanding of, and ability to, harness sustainable renewable energy sources that scale, thus inspiring the next generation's scientific minds.