Corn structure insights could optimise ethanol production

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Louisiana State University (LSU) has published a research project that revealed a different internal structure of corn than originally thought, which can assist in optimising how the plant is converted to ethanol.

“Our economy relies on ethanol, so it’s fascinating that we haven’t had a full and more precise understanding of the molecular structure of corn until now,” said LSU Department of Chemistry assistant professor Tuo Wang, who led the study.

“Currently, almost all gasoline contains about 10 percent ethanol. One-third of all corn production in the U.S., which is about 5 billion bushels annually, is used for ethanol production. Even if we can finally improve ethanol production efficiency by 1 or 2 percent, it could provide a significant benefit to society.”

According to LSU, Wang, alongside his colleagues, is the first to investigate an intact corn plant stalk at an atomic level using high resolution techniques.

Previously, it was established that cellulose, a thick and rigid complex carbohydrate that acts like a scaffold in corn and other plants, connected directly to a waterproof polymer called lignin.

Wang and his colleagues instead discovered that lignin has limited contact with cellulose in a plant. Rather, the carbohydrate called xylan connects cellulose and lignin as the glue.

It was also thought that cellulose, lignin and xylan molecules were mixed, however Wang’s research found that each entity has separate domains with differing functions.

Lignin with its waterproof qualities poses a challenge to ethanol production as it prevents sugar from being converted to ethanol within the plant. Significant research has taken place on how to break down a plant’s structure for ethanol and biofuel production. However, as of now, research hasn’t considered the full scope of a plant’s molecular structure.

“A lot of work in ethanol production methods may need further optimization, but it opens doors for new opportunities to improve the way we process this valuable product,” Wang said.

This means a more efficient enzyme or chemical can be designed to more efficiently break down the core of a plant’s biomass. This new approach can be used for biomasses in other plants and organisms as well.