Converting Corn Kernel Fiber to Ethanol

The goal of the Fiber Fermentation Project is to develop a yeast that is able to convert more of the sugars in corn to ethanol. There are some sugars in corn that make up a large percentage of the fiber that cannot be converted to ethanol. The most abundant of these sugars are xylose and arabinose, which make up 25% and 15% of the mass of corn fiber respectively. The corn fiber is an undervalued portion of the kernel that is currently found in either the DDGS or corn gluten feed co-products.

The inability to convert these sugars to ethanol results in more than 10 billion pounds of corn fiber, which is sold as a low-cost animal feed. This decreases the profitability of ethanol production from corn. There has been good progress in developing a yeast capable of fermenting xylose. Arabinose utilization, however, has been much more difficult to attain.

Currently the NCGA is working with the Corn Refiners Association and with the National Renewable Energy Laboratory to develop an arabinose utilizing yeast. Good progress has been made during the past year towards solving one of the more difficult steps in conversion. This achievement takes us much closer towards a yeast that is able to efficiently ferment corn to ethanol.

Utilization of the fiber in ethanol production process influences profitability on this 700 million bushel market.