Project Description
In the face of climate change, one of the most pressing challenges of our time, it is imperative that we address the issue of methane, a highly potent greenhouse gas with approximately 25 times the heat-trapping capacity of CO2. The agricultural sector, particularly livestock farming, significantly contributes to methane emissions, accounting for approximately 36% of the total methane released in the United States. While renewable technologies, such as dairy digesters, have been introduced to mitigate greenhouse gas emissions, methane still escapes due to the presence of methanogenic bacteria within these systems. Recognizing the urgent need for a more effective solution, our iGEM team is passionately committed to developing an innovative approach that will substantially reduce methane emissions from dairy digesters. By doing so, we aim to make a meaningful contribution to mitigating climate change and fostering a more sustainable future.
To accomplish our goal, we will leverage the existing iGEM biobricks containing genes for methane monooxygenase, an enzyme complex found in methanogens that catalyzes the oxidation of methane to methanol. Previous teams have contributed to the development of this plasmid, which serves as a valuable foundation for our work.
Our focus lies in adapting the plasmid sequence to suit the specific characteristics of E. coli, our chosen host organism. Optimizing the plasmid sequence is crucial to achieve high-level expression of methane monooxygenase in E. coli. We will employ various strategies to enhance protein production, such as codon optimization, promoter engineering, and ribosome binding site (RBS) selection. By tailoring the plasmid to the unique features of E. coli, we aim to maximize protein yield and ensure efficient conversion of methane to methanol.
Methane monooxygenase is a complex enzyme composed of multiple subunits that must assemble correctly to form a functional protein. To overcome potential challenges associated with subunit misfolding and aggregation, we will utilize chaperone proteins. Chaperones play a crucial role in assisting protein folding, preventing misfolding, and promoting proper assembly. By introducing specific chaperones into our engineered E. coli strains, we aim to enhance the folding efficiency of MMO subunits and improve overall enzyme activity.
Throughout our project, we plan to collaborate with experts in the fields of environmental engineering, microbiology, and synthetic biology to leverage their knowledge and expertise. Additionally, we aim to engage with our local agricultural communities, wastewater treatment facilities, and relevant researches to raise awareness about our research and its potential impact. We will organize outreach programs to educate and inspire future scientists and the general public about synthetic biology and the future impacts of our project.
Our proposed solution:
Inspirations
- 2021 Wageningen_UR Cattelyst
- 2014 Braaunschweig E. Cowli
References
1. Lipscomb, J. D. Biochemistry of the Soluble Methane Monooxygenase. Annual Review of Microbiology 48, 371–399 (1994).
2. Holmes, A. J., Costello, A., Lidstrom, M. E. & Murrell, J. C. Evidence that participate methane monooxygenase and ammonia monooxygenase may be evolutionarily related. FEMS Microbiology Letters 132, 203–208 (1995).
3. Bennett, R. K. et al. Expression of soluble methane monooxygenase in Escherichia coli enables methane conversion. 2021.08.05.455234 Preprint at https://doi.org/10.1101/2021.08.05.455234 (2021).
4. West, C. A., Salmond, G. P. C., Dalton, H. & Murrell, J. C. Functional expression in Escherichia coli of proteins B and C from soluble methane monooxygenase of Methylococcus capsulatus (Bath). Microbiology 138, 1301–1307 (1992).
5. Baik, M.-H., Newcomb, M., Friesner, R. A. & Lippard, S. J. Mechanistic Studies on the Hydroxylation of Methane by Methane Monooxygenase. Chem. Rev. 103, 2385–2420 (2003).
6. Murrell, J. C., Gilbert, B. & McDonald, I. R. Molecular biology and regulation of methane monooxygenase. Arch. Microbiol. 173, 325–332 (2000).