Studies of bacteria first found in Yellowstone's hot springs are furthering efforts at the Department of Energy's BioEnergy Science Center toward commercially viable ethanol production from crops such as switchgrass.
The current production of ethanol relies on the use of expensive enzymes that break down complex plant materials to yield sugars that are fermented into ethanol. One suggested cheaper alternative is consolidated bioprocessing, a streamlined process that uses microorganisms to break down the resistant biomass.
"Consolidated bioprocessing is like a one-pot mix," said Oak Ridge National Laboratory's Richard Giannone, coauthor on a BESC proteomics study that looked at one microorganism candidate. "You want to throw plant material into a pot with the microorganism and allow it to degrade the material and produce ethanol at the same time."
The BESC study focused on Caldicellulosiruptor obsidiansis, a naturally occurring bacterium discovered by BESC scientists in a Yellowstone National Park hot spring. The microorganism, which thrives at extremely high temperatures, breaks down organic material such as sticks and leaves in its natural environment, and scientists hope to transfer this capability to biofuel production tanks.
In a paper featured on the cover of the Journal of Proteome Research, the BESC team conducted a comparative analysis of proteins from C. obsidiansis grown on four different carbon sources, ranging from a simple sugar to more complex substrates such as pure cellulose and finally to switchgrass. The succession of carbon substrates allowed researchers to compare how the organism processes increasingly complex materials.
"This progression helps us look at how proteins change given different carbon substrates," Giannone said. "One of the goals is to identify new proteins that we haven't seen before. If an unknown protein doesn't show up on the simple sugars or cellulose,
|Contact: Morgan McCorkle|
DOE/Oak Ridge National Laboratory