Iowa State University researcher works to modify, increase corn starch

AMES, Iowa -- An Iowa State University researcher has developed technology that allows corn plants to produce more starch and also modified starch.

Martha James, a collaborator in the department of biochemistry, biophysics and molecular biology, is working to produce the two different types of corn starch modifications.

One starch modification would allow each corn kernel to produce more starch. Another modification would allow corn starch to be used commercially and industrially more easily and less expensively.

James is doing this research with Alan Myers, professor in biochemistry, biophysics and molecular biology. James and Myers have formed Starch Design Ltd., an ISU start-up company with exclusive rights to an intellectual property portfolio licensed from the Iowa State University Research Foundation.

For the modification designed to produce more starch, James has examined the starch synthetic pathway in the plant.

"We've studied the pathway for 15 years, so we really understand it," said James. "Now we know that if we alter a specific association between two proteins in that pathway, it allows more starch to accumulate."

The endosperm is the part of the corn kernel where starch is contained. But the amount of starch that accumulates in the endosperm is controlled in part by this protein-protein interaction, said James.

By blocking this interaction, James has found a way to stop that message. Therefore, the starch in the endosperm continues to grow.

"We've reallocated the carbon in the kernel to starch," she said. "That will allow producers to plant fewer plants and get the same amount of starch."

Increasing the amount of starch could have benefits beyond the farm.

"We hope it will address the food versus fuel debate," James said. "So this technology may help lessen the competition between them."

James is also researching another modification that will change the structure of the starch.

Currently, starch from the corn kernel needs to be processed before it can be used in various commercial and industrial applications.

James wants to change that.

"What we're doing is attempting to modify the structure of the starch in the corn plant so it can be harvested and used directly without having to undergo any post-harvest treatment," said James.

For instance, James' research has allowed her to manipulate starch so that it degrades quickly. This type of starch can be processed into ethanol more cheaply than current starch.

James is also working to manipulate starch so it degrades slowly. This type of starch may be a helpful food additive for people who are at risk of diabetes.

Starch Design Ltd. offers the technology commercially and can be contacted at