Put a Tiger Lily in Your Tank

Herbaceous and woody plants like the tiger lily are a good source of biomass, which is proving to be a precursor to ethanol and other biofuels. Researchers in the U.S. Forest Service Forest Products Laboratory and the Department of Energy Genome Institute completed the genomic sequence of the xylose-fermenting yeast, Pichia stipitis and are hoping to engineer the microbe to commercially produce ethanol. They say that it ferments sugars derived from biomass and future biomass refineries can produce ethanol from a mixture of sugars from plant material.

This process proves useful but has a small setback because biomass is made of cellulose and corn, the other source of ethanol, is made of starch. Starch is easier to ferment than cellulose, which protects and supports plants. Cellulose makes up biomass in combination with hemicellulose, which creates another difficulty. Hemicellulose can break down into simple sugars through acid treatment, creating xylose, arabinose, glucose, and some mannose. But the glucose is used first by microbes and its use represses the use of the other sugars. Thus, one must create an organism that can work with multiple sugars. Pichia stipitis comes into the picture here because it ferments xylose. The overall goal in this process is to modify the genetic makeup of Pichia stipitis so that it can ferment hemicellulose and cellulose. I encourage you all to read the article that is the source of this post and it can be found at http://www.chemistry.org/portal/a/c/s/1/feature_ent.html?id=c373e911f936b7b88f6a17245d830100.