Background: In the midst of declining fossil fuel reserves and a great expansion of natural gas production increased efforts has been expended in seeking to commercialize the conversion of natural gas into chemical feedstocks and fuels as an alternative to petroleum. Many methods to convert methane to ethylene have been developed. Researchers at the University of California Davis have developed novel methods using Escherichia coli as a biocatalyst to convert ethylene to acetyl-CoA and ultimately n-butanol which is a potential fuel substitute and an important C4 chemical feedstock. Technology Description: Large natural gas reservoirs exist throughout the world and have an enormous potential as a clean fuel and chemical feedstock. Currently the vast majority of natural gas is used for heating purposes. This is due largely to the properties of methane as a heating fuel as well as the difficulty in economically converting methane into larger higher value chemicals and liquid fuels. Therefore there is significant interest in green chemical synthesis methods such as bio-assimilation which use genetically engineered host organisms to generate desired compounds. Bio-assimilation of ethylene has been reported in methanotrophs (prokaryotes that use methane as both a carbon source and an energy source). However no large scale applications have been demonstrated. This is mainly due to difficulties in maintaining cultures and a lack of tools for genetic modification. alternatively the biological host bacteria E. coli has many genetic tools and well-established large scale bio-assimilation application methods. Since ethylene is already a high volume chemical feedstock used in the chemical industry a high performance ethylene assimilation pathway in E. coli could enable immediate industrial applications. Researchers at the University of California Davis have developed bio-assimilation pathways for the conversion of ethylene to acetyl-CoA using E. coli as a biocatalyst. Subsequently acetyl-CoA can be used to synthesize n-butanol and other chemicals using established biosynthetic pathways. Applications: Biological conversion of ethylene to acetyl-CoA n-butanol and other chemicals
1) Green chemistry methods use less-toxic catalysts lower temperatures and avoid organic solvents. 2) E. coli has many genetic tools and well-established large scale bio-assimilation applications. 3) Biological plants are more energy efficient and have less capital costs than chemical plants.