Bioprocess engineer Y.H. Percival Zhang is working on a process that would transform trees and other non-edible plants into food. In an article from Science Now, Zhang explains the process that turns the cellulose from wood into starch (amylose), the compound that makes up 40 percent of people's diets.
Bioprocess engineer Y.H. Percival Zhang is working on a process that would transform trees and other non-edible plants into food. In an article from Science Now, Zhang explains the process that turns the cellulose from wood into starch (amylose), the compound that makes up 40 percent of people's diets.
The idea germinated from the fact that both cellulose and starch are made of glucose molecules. The only difference is how those molecules are arranged. To convert one into the other, the Zhang and his research team at Virginia Polytechnic Institute and State University in Blacksburg genetically modified E. coli bacteria so it would produce an enzyme capable of breaking apart the glucose molecules in such a way that they would rearrange themselves into starch.
Zhang cited his heritage for his interest in alternative food sources. "Food security has always been the number one question for nearly 5,000 years of Chinese history," Zhang told Science Now. "Without enough food, crises happened and dynasties shifted."
The process as it exists now converts up to a third of the cellulose into amylose, resulting in a white powder that tastes slightly sweet. The remaining two-thirds becomes glucose, which can be used to make ethanol. The amylose has also been used to make a transparent, biodegradable plastic.
At present, the process would cost $1 million to turn 200 kilograms of crude cellulose into enough food to meet a person's carbohydrate needs for 80 days. However, Zhang estimates in five to 10 years, companies could do it for 50 cents per person per day.
