Biofuels like ethanol are all the talk these days with ever increasing gas prices. The problem with ethanol is that it can only be made from sugars in plants like corn. Ethanol is made by fermenting sugars called hexoses with yeast. This is the most edible part of the plant. So think of a stalk of corn. It’s really tall and leafy. Then there’s the ear of corn that’s wrapped up in even more leaves. The only part of the plant that can be converted into ethanol is the white stuff inside the kernel. That’s a lot of waste. Researchers in the Netherlands have found a way to make ethanol from agricultural waste (all those corn stalks and leaves) with the help of an enzyme found in the gut of Indian elephants and also fungus. The enzyme was actually discovered in elephant poop in 1984 and allows the elephants to convert pentose sugars like xylose to xylulose. Blah, blah, blah…what is she talking about? Simply put, we can’t digest pentose sugars and nether can yeast. This enzyme breaks down pentose sugars to something digestible.
The researchers in the Netherlands have taken the gene that produces this enzyme and have cloned into yeast except they used the gene isolated from a fungus. This gene allows the yeast to break down both kinds of sugars and improve the yield of bioethanol. There are still a few glitches. The yeast can’t tolerate the acids produced when the sugars are freed from plants, but the team has plans for making the yeast resistant and predict that they will be applied for ethanol production within the next five years.