Engineering of C1 metabolism in an oxygenic phototrophic microbe

Development of consolidated bioprocessing catalysts for the conversion of C1 substrates (CO₂ and CH₄) into fuels and products has long been recognized as a viable option to minimize the impact of greenhouse gas emission, and to ensure food/feed security. An increasing number of bioprocesses are being developed using native phototrophs (CO₂ into products) and methanotrophs (CH₄ into products). Both systems provide significant economic challenges due to the physical and chemical nature of substrates. Partitioning of CO₂ into targeted products requires high amounts of energy and the volumetric productivity is low which complicates downstream processing. While high-energy content and carbon percentage (75%) makes methane an ideal C1 feedstock, requirements of energy (obtained by converting CH₄ into CO₂) and oxygen puts significant economic constraint for its conversion into fuels and products. MOgene Green Chemicals is using an alternative approach to overcome such economic constraint by engineering a cyanobacterium (an oxygenic phototroph) for utilization of CH₄ and CO₂. Our bioprocess is less dependent on sunlight and would operate round-the-clock while the economics of biotransformation is significantly improved because carbon loss is minimized, oxygen for CH₄ oxidation is provided internally, and high volumetric productivity is achieved. The resulting consolidated bioprocessing catalyst will enable a cost-effective conversion of CH₄ and CO₂ into fuels and products.

This work is supported, in part, by the Advanced Research Projects Agency-Energy (DE-AR0000457), Department of Energy.