A TEAM of researchers at the Virginia State University & Polytechnic Institute succeeded in transforming cellulose into starch, a process that has the potential to provide a previously untapped nutrient source from plants not traditionally thought of as food crops.
The research was published last week in the early edition of Proceedings of the National Academy of Sciences.
Y.H. Percival Zhang, an associate professor of biological systems engineering in Virginia Tech's College of Agriculture & Life Sciences and College of Engineering, led a team of researchers in the project that could help feed a growing global population.
Starch is one of the most important components of the human diet, providing 20-40% of peoples' daily caloric intake, an announcement said.
Cellulose is the supporting material in plant cell walls and is the most common carbohydrate on Earth.
This new development opens the door to the potential that food could be created from any plant, reducing the need for crops to be grown on valuable land that requires fertilizers, pesticides and large amounts of water, the researchers said. Zhang's team produced amylose, a linear resistant starch that is not broken down in the digestion process and acts as a good source of dietary fiber.
This discovery holds promise on many fronts beyond food systems, the announcement said.
"Besides serving as a food source, the starch can be used in the manufacture of edible, clear films for biodegradable food packaging," Zhang said. "It can even serve as a high-density hydrogen storage carrier that could solve problems related to hydrogen storage and distribution."
Zhang used a novel process involving cascading enzymes to transform cellulose into amylose starch.
"Cellulose and starch have the same chemical formula," Zhang pointed out. "The difference is in their chemical linkages. Our idea is to use an enzyme cascade to break up the bonds in cellulose, enabling their reconfiguration as starch."
The new approach takes cellulose from non-food plant material such as corn stover, converts about 30% to amylose and hydrolyzes the remainder to glucose that is suitable for ethanol production. Corn stover consists of the stem, leaves and husk of the corn plant that remain after harvesting. However, the process works with cellulose from any plant.
This bioprocess -- called "simultaneous enzymatic biotransformation and microbial fermentation" -- is easy to scale up for commercial production, the announcement said, and it is environmentally friendly because it does not require expensive equipment, heat or chemical reagents and does not generate any waste.
Virginia Tech noted that the biotransformation technology is covered under a provisional patent application.