A team of researchers led by a UH chemical and biomolecular engineer will design microorganisms that can convert natural gas liquids (NGLs) into useful products more efficiently than current technologies.
The National Science Foundation awarded Associate Professor Patrick Cirino more than $300,000 to study and engineer microorganisms that can metabolize hydrocarbons, including NGLs. Once the activities of the enzymes responsible for metabolizing NGLs are uncovered, Cirino and his collaborators – Ramon Gonzalez, a metabolic engineer at Rice University, and Squire Booker, a biochemist at Penn State University – will create metabolically engineered microorganisms capable of converting NGLs into a variety of valuable products.
What are NGLs?
The production of natural gas in the U.S. has reached record highs with the use of new extraction methods such as hydraulic fracturing and horizontal well drilling. Natural gas reserves also contain compounds called natural gas liquids, or NGLs, which are hydrocarbons that are harvested along with the natural gas. Ethane, propane, butane and isobutane are all examples of NGLs.
NGLs are useful chemicals that span almost all sectors of the economy, but current methods of purifying these low-value hydrocarbons are energy intensive, and their conversion to higher value products is inefficient. With the increased production of natural gas comes increased production of NGLs in the U.S., and that has led to some concerns over processing and distribution constraints in coming years.
A better way
Cirino believes there’s a better way to turn NGLs and longer hydrocarbons into other products, and he’s looking to nature for the answers.
One approach that microorganisms use to metabolize hydrocarbons is to activate these compounds by the addition of a metabolite called fumarate, which plays an essential role in the metabolic process. The resulting fumarate adducts are broken down into smaller molecules that can then be used as building blocks for the biosynthesis of new chemicals. This metabolic conversion of hydrocarbons into new chemicals doesn’t generate waste or require large amounts of energy, but isn’t well understood.
“We have a good handle on which genes are at play in the natural systems. We can clone those genes, but getting the enzymes to work in a repurposed context is tricky. We will have to engineer them to do specific tasks,” Cirino said.
Ultimately, Cirino hopes to metabolically engineer microorganisms that can convert NGLs into a variety of desirable biochemicals like butanol, a biofuel.
If successful, Cirino said the project will not only provide fundamental insights into how certain microorganisms metabolize hydrocarbons; “It will also provide a novel engineering platform for activating hydrocarbons and using them as feedstocks in bioprocesses.”