EAPSI: The enzymatic conversion of methane to methanol

Kowalski Ann, Fort Collins CO

Investigators

Abstract

Advanced drilling techniques have increased access to natural gas, which is often emphasized as a global energy source. However, high costs for steam reforming and pipeline infrastructure can make natural gas production impractical at remote locations. Some bacteria use methane, the primary component of natural gas, as an energy source by converting methane to methanol with the enzyme methane mono-oxygenase (MMO). In collaboration with Dr. Kini, an expert in mini-enzyme design at the National University of Singapore, this project will investigate the potential for improvement to an existing MMO enzyme. The project will require research in improvements to modeling enzymes like MMO, and investigation of methods to immobilize MMO on a solid surface. The economical conversion of methane to methanol at industrial scale provides two significant benefits: reducing potent greenhouse gas emissions from methane flaring and generating methanol as an efficient fuel source and commodity chemical. Starting with an active fragment of the enzyme, computationally redesigned for solubility, the project will investigate further improvement of the construct via directed evolution - purposeful mutations to the structure of the protein that alter and may enhance desirable qualities like stability and activity. First, the expressed fragments must be loaded with Cu+2 at the active sites. Next, propylene epoxidation activity can be tested by HPLC and compared to that of the wild type. The design space can then be probed by directed evolution. Enzyme fragments with considerable activity will be further stabilized for industrial use by immobilization to a host scaffold. The result will be a solid-state biocatalyst with retained activity and enhanced qualities for industrial application: stability after multiple recycles, performance under harsh conditions, and immobilization for ease of separation. This NSF EAPSI award is funded in collaboration with the National Research Foundation of Singapore.