Indiana University (IU) biologists believe they have found a faster, less expensive and cleaner way to increase bioethanol production by using nitrogen gas in place of more costly industrial fertilizers. The discovery could save industry millions of dollars and make cellulosic ethanol – made from wood, grasses and inedible parts of plants – more competitive with corn ethanol and gasoline, according to the university.

An IU team, led by James B. McKinlay, an assistant professor of biology, found that the bioethanol-producing bacterium Zymomonas mobilis can use nitrogen gas (N₂) as a nitrogen source, something that the more traditional ethanol-producer, baker’s yeast, cannot do.

“When we discovered that Z. mobilis could use N₂ we expected that it would make less ethanol. ” McKinlay says. “To our surprise the ethanol yield was unchanged when the bacteria used N₂." He says that under certain conditions, the bacteria converted sugars to ethanol faster when they were fed N₂.

The researchers estimated that using N₂ gas, which can be produced on-site at production facilities, could save an ethanol production facility more than $1 million a year. Using N₂ gas could also have environmental benefits such as avoiding carbon dioxide emissions associated with producing and transporting the industrial fertilizers.

A provisional patent has also been filed with the United State Patent and Trademark Office. The research was published in the journal Proceedings of the National Academy of Sciences.

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