LOGAN -- What if greenhouse gas could be converted into fuel for an energy-hungry world?
"That's currently a 'holy grail' of science," said Utah State University biochemist Lance Seefeldt. "Imagine the far-reaching benefits of capturing environmentally damaging byproducts of burning fossil fuels and using them to make alternative fuels."
That dream is one step closer because of work done by Seefeldt and USU graduate student Zhiyong Yang.
The scientists, working with colleagues Vivian Moure, of Brazil's Federal University of Parana, and Dennis Dean, of Virginia Tech, have genetically modified a bacteria that lives in soil and used it to convert carbon dioxide into methane.
Yang was lead author on the research paper the group published this month in the online early edition of the National Academy of Sciences.
"We've only been able to convert a tiny amount of carbon dioxide to methane, and our process is very slow and inefficient," said Yang, a USU doctoral student who earned his first doctorate in organic chemistry at China's Nankai University.
"But now we can begin to understand the chemistry. We can establish the mechanistic principles for this conversion on which other chemists can build to design better, more efficient catalysts to accomplish this process."
Seefeldt has long studied the bacteria in soil and was intrigued by bacterial enzymes known as nitrogenases, which use air to help produce fertilizer.
The enzymes looked similar to nitrogen in the air. But breaking apart carbon dioxide molecules is difficult because of the molecule's stability, Seefeldt said.
"We asked, 'Why can't this enzyme do chemistry on carbon dioxide?' It wasn't until recently we realized we could remodel the area where carbon dioxide would naturally bind."
The researchers used genetic engineering to remodel the nitrogenases proteins.
"An advantage of our process is, it provides a path to learn how to turn carbon dioxide into useful chemicals and fuels," Yang said.
"The continuing challenge will be figuring out how this process works and then transferring that knowledge to the construction of robust catalysts that can remove carbon dioxide from the atmosphere and turn it into something useful."
Seefeldt said the group's work is based on principles and findings of many scientists who came before.
"The work goes back more than 60 years, when the first scientists started to purify this enzyme," he said.
"Our work here goes back about 20 years now. Every step in the process is a development, and this was a big step. Having the paper accepted into a very prestigious journal was a sign of the magnitude."
Seefeldt said top labs are already at work trying to apply the new knowledge to design a better catalyst.
"This is moving faster now," he said. "Things are going wonderfully. We are excited about this discovery, but we have a lot of work ahead of us. A breakthrough opens a whole new area, then there's lots of labor, and you hope for another breakthrough."
Seefeldt said he's especially proud that a graduate student could be part of the discovery.
"There are a number of examples of students who worked at USU who have gone off and become professors, scientists at major corporations or medical doctors," he said. "It's one of the proud moments we have, training our students to make major contributions to their field."