U.S. Department of Energy Office of Biological and Environmental Research

BER Research Highlights

Engineering Thermophilic Bacteria for Efficient Fermentation of Plant Biomass
Published: June 03, 2013
Posted: July 18, 2013

Higher temperatures make plant biomass more accessible for processing, so thermophilic bacteria, which are active at higher temperatures than other bacteria, are promising candidates for biofuel production systems. To take full advantage of their potential in consolidated bioprocessing, efficient genetic tools are needed to metabolically engineer the thermophile. Researchers at the U.S. Department of Energy’s BioEnergy Science Center have been developing a series of genetic tools to manipulate Caldicellulosiruptor bescii. C. bescii is one of the most promising thermophiles for deconstructing and fermenting lignocellulose from nonfood plants. New research demonstrates a gene replacement strategy used to delete the lactate dehydrogenase gene from C. bescii. Because the plasmid contains a gene for which there is both positive and negative selection, it is possible to select first for recombination of the deleted ldh gene and then for loss of the plasmid sequences. This method allows clean genetic insertions and deletions, leaving no residual genetic material so that the method can be used repeatedly for adding and subtracting genes for metabolic engineering. The C. bescii strain containing the ldh gene deletion exhibited the expected metabolism changes, namely the engineered strain no longer produced lactate and had increased acetate and H2 production. This gene replacement demonstration paves the way for further genetic manipulation of C. bescii to produce desired biofuel fermentation products directly from plant biomass.

Reference: Cha, M., D. Chung, J. G. Elkins, A. M. Guss, and J. Westpheling. 2013. “Metabolic Engineering of Caldicellulosiruptor bescii Yields Increased Hydrogen Production from Lignocellulosic Biomass,” Biotechnology for Biofuels 6, 85. DOI: 10.1186/1754-6834-6-85. (Reference link)

Contact: Kent Peters, SC-23.2, (301) 903-5549
Topic Areas:

  • Research Area: Genomic Analysis and Systems Biology
  • Research Area: Microbes and Communities
  • Research Area: Plant Systems and Feedstocks, Plant-Microbe Interactions
  • Research Area: Sustainable Biofuels and Bioproducts
  • Research Area: DOE Bioenergy Research Centers (BRC)
  • Research Area: Biosystems Design

Division: SC-23.2 Biological Systems Science Division, BER


BER supports basic research and scientific user facilities to advance DOE missions in energy and environment. More about BER

Recent Highlights

Aug 24, 2019
New Approach for Studying How Microbes Influence Their Environment
A diverse group of scientists suggests a common framework and targeting of known microbial processes [more...]

Aug 08, 2019
Nutrient-Hungry Peatland Microbes Reduce Carbon Loss Under Warmer Conditions
Enzyme production in peatlands reduces carbon lost to respiration under future high temperatures. [more...]

Aug 05, 2019
Amazon Forest Response to CO2 Fertilization Dependent on Plant Phosphorus Acquisition
AmazonFACE Model Intercomparison. The Science Plant growth is dependent on the availabi [more...]

Jul 29, 2019
A Slippery Slope: Soil Carbon Destabilization
Carbon gain or loss depends on the balance between competing biological, chemical, and physical reac [more...]

Jul 15, 2019
Field Evaluation of Gas Analyzers for Measuring Ecosystem Fluxes
How gas analyzer type and correction method impact measured fluxes. The Science A side- [more...]

List all highlights (possible long download time)