New Metabolic Pathway for Biofuels

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MIT Technology Review, Chemistry World, and UCLA reported this week on research led by Prof. James Liao, that resulted in a highly efficient method for breaking down glucose for use in biofuels.

Excerpt from UCLA Newsroom (by Matthew Chin): UCLA chemical engineering researchers have created a new synthetic metabolic pathway for breaking down glucose that could lead to a 50 percent increase in the production of biofuels.

The new pathway is intended to replace the natural metabolic pathway known as glycolysis, a series of chemical reactions that nearly all organisms use to convert sugars into the molecular precursors that cells need. Glycolysis converts four of the six carbon atoms found in glucose into two-carbon molecules known acetyl-CoA, a precursor to biofuels like ethanol and butanol, as well as fatty acids, amino acids and pharmaceuticals. However, the two remaining glucose carbons are lost as carbon dioxide.

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Left: Colonies of E. coli genetically modified with the new pathway (courtesy of UCLA Newsroom);
Right: Photo courtesy of RSC Chemistry World

Glycolysis is currently used in biorefinies to convert sugars derived from plant biomass into biofuels, but the loss of two carbon atoms for every six that are input is seen as a major gap in the efficiency of the process. The UCLA research team’s synthetic glycolytic pathway converts all six glucose carbon atoms into three molecules of acetyl-CoA without losing any as carbon dioxide.

The research was published online Sept. 29 in the peer-reviewed journal Nature. The principal investigator on the research is James Liao, UCLA’s Ralph M. Parsons Foundation Professor of Chemical Engineering, chair of the chemical and biomolecular engineering department, and Professor of chemistry and biochemistry department. Igor Bogorad, a graduate student in Liao’s laboratory, is the lead author. You may access the full articles here:  MIT Technology Review / RSC Chemistry World / UCLA Newsroom Team2
Prof. James Liao (second from right) with his research group Short Biography of Prof. James Liao

One of the worldwide most appreciated experts in metabolic engineering and synthetic biology, Professor Liao obtained his Bachelor of Science from the National Taiwan University.  It was followed in 1987 by a Ph.D. degree at the University of Wisconsin-Madison and by a period spent as a research scientist at Rochester, working for the Eastman Kodak Company.  In 1990 he joined Texas A&M University and in 1997, he moved to University of California, Los Angeles. His current research interests are mainly focused on biological synthesis of fuels and chemicals, carbon and nitrogen assimilation, metabolic engineering and synthetic biology, transcriptional and metabolic networks analysis and fatty acid metabolism.  Together with his research group, Professor Liao developed synthetic pathways for production of isobutanol and other higher alcohols from various raw materials.  He deepened biological regulatory networks at the systems level, developing both experimental and computational methods for better understanding and predicting cellular behavior.  They developed a breakthrough technique, called Network Component Analysis (NCA), using mRNA expression and transcriptional network connectivity to determine network component dynamics, functions, and interactions.  The team designed novel synthetic gene-metabolic circuits, in order to demonstrate system-wide understanding of cellular regulation. During his outstanding scientific career, he has been awarded with many recognition.  Among them, the NSF Young Investigator Award in 1992, the Merck Award for Metabolic Engineering in 2006 and the Food, Pharmaceutical and Bioengineering Division award of American Institute of Chemical Engineers in the same year.  He then won the Charles Thom Award of the Society for Industrial Microbiology in 2007 and the Marvin Johnson Award of American Chemical Society in 2009.  In 2010, he received the Presidential Green Chemistry Challenge Award.  In 2012, Professor James Liao was proclaimed the White House Champion of Change in Renewable Energy and in 2013, he was elected to the National Academy of Engineering.  He was also selected as a co-winner for the 2013 ENI Award in Renewable and Non-Conventional Energy.