Corn fiber leftovers from ethanol production can be processed more efficiently into a higher value product called xylitol by making sure glucose doesn't interfere with the transformation process. Xylitol is a low-calorie sweetener that can cost up to $3 per pound. Currently made from acid-treated fibers of birch wood, it is used in foods, mouthwashes, toothpastes, and chewing gums, where it imparts a minty-cool taste. But xylitol can also be made from xylose, one of the sugars left over when corn fiber is broken down. A yeast called Pichia guilliermondii can convert corn fiber's xylose into xylitol, but that process can be hindered by glucose, another of the leftover sugars from fermented corn fiber. The problem: When P. guilliermondii comes in contact with both glucose and xylose in fermenting corn fiber, it "prefers" the glucose. Like a child who would rather gorge on ice cream than spinach, it spends its energy on gobbling the glucose, which leaves the yeast relatively ineffective in carrying out the xylose-to-xylitol transformation. The solution devised by ARS scientists: Send in the B team. The scientists add an initial batch of P. guilliermondii to the fermenting fibers to devour the glucose. Then they mix in more P. guilliermondii to tackle the task of transforming the xylose into xylitol. Xylitol has one-third fewer calories than conventional sugar and about the same sweetening power. Currently, it commands a $28 million market. Because a biotechnological xylitol manufacturing approach involving corn fiber should require less energy, the scientists envision more research will drive production costs down and market volume up.

National Center for Agricultural Utilization Research, Peoria, IL
Timothy D. Leathers, (309) 681-6377, leathetd@ncaur.usda.gov
Badal C. Saha, (309) 681-6276, sahabc@ncaur.usda.gov

Wheat-gluten-based formulations of any of at least three types of insecticides can be strategically sprayed on plant leaves to control the adult beetle stage of the corn rootworm, instead of larvae. The new formulations—containing a feeding stimulant and pyrethroids, carbamates, or organophosphates—are effective when applied at about one-tenth the rate of insecticides normally buried in soil to control larvae. By rotating use of these insecticide types, farmers may help ensure that insecticide-resistant strains of corn rootworms don't quickly develop in their fields. In 1996, ARS patented the use of gluten to help stick sprays to leaves. Having first extensively researched sprays containing microbial insecticides, the scientists worked under a cooperative research and development agreement with researchers of Trécé Inc. of Salinas, CA, to develop chemical insecticide formulations. Trécé licensed the invention and now markets the formulations under the name CIDETRAK. The partners have extended the CRADA into 2001 as they test the potential of other insecticides.

National Center for Agricultural Utilization Research, Peoria, IL
Robert W. Behle, (309) 681-6225, behlerw@ncaur.usda.gov

A new, soy-based foam extrusion glue stands ready to give the plywood industry what every industry wants: faster production at lower cost. To achieve this, ARS researchers used soy flour to replace the animal blood protein in plywood glue. Concerns about a limited supply of animal blood and health issues prompted the search for alternative protein extenders. Soy flour made the best glue and—at 22 cents per pound—the glue it produces is 50 cents per 100 kilograms cheaper than conventional formulations. The glue mix is made up of 3.5 to 5.5 percent soy flour. It also requires less drying time, uses less water, and produces less waste than conventional plywood glues. It could create an added domestic market for nearly one-half million bushels of soybeans annually. The United Soybean Board provided funding for this project.

National Center for Agricultural Utilization Research, Peoria, IL
Milagros P. Hojilla-Evangelista, (309) 681-6350, hojillmp@ncaur.usda.gov