EESA’s Advanced Research Projects Agency–Energy (ARPA-E) effort, the Methylase Project, aims to develop biological systems for direct conversion of CO2 or CH4 to liquid transportation fuels. Methane is the main component of gaseous/solid fossil fuel resources, and constitutes one of the largest organic carbon reserves. It is also a main component of anaerobic decomposition processes that produce biodigester gas, landfill gas, sewage gas, and other types of biogas, and represents a significant contributor to greenhouse gas emissions. Methane is an inexpensive and plentiful feedstock with a high H:C ratio and is highly valued as an energy-rich fuel and raw material for chemicals. However, methane remains a gas at surface temperatures and pressure and, therefore, is problematic and costly to transport, a drawback that is exacerbated by the fact that a large portion of the known natural gas reserves are located in remote areas of the world.
The goal of this project is to engineer a bacterium for efficient conversion of methane to liquid transportation fuel.
We focus on:
- Bio-engineering of key enzymes
- Installing and enhancing a pathway for biofuel synthesis
The rationale for the Methylase Project is three-fold:
- Bio-conversion of methane avoids shortcomings associated with chemical methane conversion.
- De novo construction of a methylase is a novel approach and departs from earlier efforts in engineering methanotroph metabolism and in improving biological methane-to-liquid (MTL) fuel production.
- As opposed to the methane monooxygenases (MMOs) in methanotrophs, the constructed methylase is intended to operate without consumption of reducing power.
The objectives for the Methylase Project are to:
- Employ rational protein engineering in combination with accelerated evolution to convert an existing carboxylase to a methylase enzyme.
- Develop a high-throughput assay for methylase activity.
- Incorporate the methylase into a novel methane assimilation (M-A) metabolic cycle that will allow for assimilation of CH4 into Acetyl-CoA, a fuel intermediate.
- Install the methylase and M-A cycle in bacteria for conversion of CH4 to hydrocarbon fuels.
* now at PNNL