Sunday, April 21, 2013

Could Wood Feed the World?


Summary:

The main ingredient of wood, cellulose, is one of the most abundant organic compounds on Earth and a dream source of renewable fuel. Now, bioengineers suggest that it could feed the hungry as well. In a new study, researchers have found a way to turn cellulose into starch, the most common carbohydrate in the human diet. Now, for the first time, it appears there may be a practical way that cellulose could also feed people, says bioprocess engineer Y.-H. Percival Zhang of the Virginia Polytechnic Institute and State University in Blacksburg. Zhang and his colleagues focused on starch, which makes up as much as 40% of people's diets. The idea of turning cellulose into starch is one rooted in the similarities between the compounds: Cellulose is composed of hundreds to thousands of molecules of the sugar glucose, and starch compounds are made of glucose as well, although the sugar is bonded together in different ways. To make the conversion, the researchers took genes from certain species of bacteria, soil fungi, and potatoes and then genetically modified Escherichia coli, a different bacterium and a common lab model, to produce the needed enzymes. One set of these enzymes break cellulose down into smaller molecules, while the other set builds these components into starch. Then they mixed this cocktail of enzymes with cellulose in a glass vessel. So far, the process converts up to nearly a third of the cellulose into amylose, the team reports online today in the Proceedings of the National Academy of Sciences. That compound, which is a white powder when dried, can not only be added to food but can also be made into transparent, flexible, biodegradable plastics and store hydrogen for energy applications. Zhang and his colleagues even tried some of the final product: "No taste in the beginning," Zhang says. "After chewing for a while, it tasted slightly sweet." The rest of the cellulose is turned into glucose, which can be fermented into biofuel. "No glucose released from the cellulose was wasted," Zhang says.

Personal Reaction:

I think this is incredible. It would be amazing if we could feed the world on wood! The process is still expensive, but if they learn how to do it in a less expensive way then the cost will go down. It just takes some time. This is definitely a step in the right direction to feeding a hungry world. I just worry about the loss of trees. If that’s even a concern.

Connection:

We had several presentations about trying to feed a hungry world and this process wasn’t mentioned and I thought it was very interesting. I’m surprised no one mentioned it in their presentations but this would be a great way to feed the world!  

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