Team:Reading/Description
Project Description
We aim to produce a biological photovoltaic (BPV) using the cyanobacterium Synechocystis sp. PCC 6803 (hereafter referred to as Synechocystis). This year, we are taking on the project of the 2014 Reading team, and we plan to build on the successes of their project, by increasing the efficiency of the BPV, and also to improve the concept and the practical use of the fuel cell.
Background
Solar energy is the largest source of energy available to mankind, with ~120,000 terawatts hitting the planet’s surface each year1. Worldwide, this immense natural resource is tapped via the use of photovoltaic cells in solar panels. In recent years, the emerging field of synthetic biology has produced the biological photovoltaic, a solar fuel cell, which harnesses the process of photosynthesis in living organisms to produce electricity. The maximum potential efficiency of photosynthesis as an energy capturing process is ~ 11%2, which is at the lower end of efficiency of the conventional photovoltaic. However there are many advantages to the use of BPV’s. The process of photosynthesis removes carbon dioxide from the atmosphere, so the BPV acts as a carbon sink. Also, the components of a BPV are very cheap, making the devices easily affordable and effective for developing communities with low energy demands, as well as being simple to maintain.
We have chosen to continue to build a BPV using Synechocystis PCC 6803. There a several advantages to this cyanobacterium. As a photolithoautotroph, Synechocystis requires water, sunlight, carbon dioxide, and essential minerals, making it simple and easy to culture and grow in a fuel cell. Cyanobacteria also obtain energy from sunlight at efficiencies of 3-9%, which is higher than most green plants3. A major advantage of using our chosen species of Synechocystis is that a full genome sequence is available for this organsim4, and it is far easier to genetically modify than, for example, and algal cell.
Inspiration
See how other teams have described and presented their projects:
Fuel Cell Design
With recent declines in fossil fuel cell availability and increasing concerns of the effects of global warming research into microbial fuel cells (MFCs) has been becoming more popular after the decline in 1965. Our team seeks to aid this re-emerging area with our own MFC using Synechocystis. Part of our aim is to increase the inherent efficiency of the fuel cell itself by improving bacteria electrode interactions and improve voltage generation over our prior teams efforts. To achieve this we have designed a cell that utilises the sedimentation aspect of bacteria in situ by lining the base of one half cell with the anode creating a simple biofilm which electrons can be harvested from. The cell is designed to have a large surface area and to be flat in order to make the most use of bacteria in the half cell for increased efficiency.
References
1. Blankenship, R. E. et al, Comparing Photosynthetic and Photovoltaic Efficiencies and Recognizing the Potential for Improvement. Science 332, 805-809 (2011).
2. Brenner, M. P. Engineering Microorganisms for Energy Production. (U.S. Department of Energy, 2006).
3. Ducat, D. C., Way, J. C., Silver, P. A., Engineering cyanobacteria to generate high-value products. Trends in Biotechnology 29, 95-103 (2011).
4. Kaneko, T. et al. Sequence Analysis of the Genome of the Unicellular Cyanobacterium Synechocystis sp. Strain PCC6803. II. Sequence Determination of the Entire Genome and Assignment of Potential Protein-coding Regions. DNA Res. 3, 109–136 (1996).