The chemical and physical processes for pretreating biomass help unravel the complex matrix of cell-wall components and enhance enzyme accessibility to these materials, but pretreatments also generate chemicals such as acetate that inhibit sugar fermentation to biofuels. Using a combination of adaptation, genetic engineering, and systems biology tools, BESC researchers have developed acetate-resistant strains of two industrial ethanol producers (the bacterium Zymomonas mobilis and the yeast Saccharomyces cerevisiae) by changing the expression of genes encoding transport proteins that move substances across the cell membrane. These proteins (called antiporters) transport proton and sodium ions and form gradients that are adversely impacted by the presence of acetate. By resequencing a Z. mobilis strain that had been adapted to withstand high acetate concentrations, BESC researchers discovered specific mutations in antiporter genes that enable acetate resistance. The specific antiporter mutations were validated using genetically engineered Z. mobilis and yeast showing the broad impact of these changes.
Reference: This research is reported in Yang, S., et al. 2010. “Paradigm for Industrial Strain Improvement Identifies Sodium Acetate Tolerance Loci in Zymomonas mobilis and Saccharomyces cerevisiae,” Proceedings of the National Academy of Sciences 107(23), 10395-400.
Contact: John Houghton, SC-23.2, (301) 903-8288
SC-33.2 Biological Systems Science Division, BER
BER supports basic research and scientific user facilities to advance DOE missions in energy and environment. More about BER
Mar 23, 2021
Molecular Connections from Plants to Fungi to Ants
Lipids transfer energy and serve as an inter-kingdom communication tool in leaf-cutter ants&rsqu [more...]
Mar 19, 2021
Microbes Use Ancient Metabolism to Cycle Phosphorus
Microbial cycling of phosphorus through reduction-oxidation reactions is older and more widespre [more...]
Feb 22, 2021
Warming Soil Means Stronger Microbe Networks
Soil warming leads to more complex, larger, and more connected networks of microbes in those soi [more...]
Jan 27, 2021
Labeling the Thale Cress Metabolites
New data pipeline identifies metabolites following heavy isotope labeling.
Aug 31, 2020
Novel Bacterial Clade Reveals Origin of Form I Rubisco
List all highlights (possible long download time)