Ethanol is manufactured by fermenting sugars from plant material. At present, xylose is not used, despite being the second most common type of sugar found in nature. If ethanol can be successfully made from xylose then ethanol production could increase by over 20 per cent – to the benefit of cheaper environmentally friendly fuel.
Nadia Skorupa Parachin has tested enzymes that she extracted from garden soil and the first results show that her enzymes bind xylose more efficiently than those that have been tested previously.
Parachin began by extracting DNA from a soil sample, then she cut it into small pieces. She was then able to build up a DNA library. Next she identified the most appropriate genes by coupling enzyme activity to growth on xylose.
“In order for carbohydrates in forestry, plant and waste products to be used for ethanol production, enzymes are required in the yeast that ‘eat up’ the sugar and convert it into ethanol. If we just want to make use of the glucose then normal baker’s yeast is sufficient. However, if the xylose is also to be converted to ethanol, then genetic modifications have to be made to the yeast”, explains Ms Skorupa Parachin, who has recently patented her newly discovered enzymes.