Saccharomyces Yeast for Cellulose Ethanol

Ethanol is recognized as one of the most desired renewable fuels for transportation to replace gasoline.  It is an environmentally friendly fuel and can be used alone or blended with gasoline in any ratio.  It is also a renewable fuel that can be readily produced now.  Adding just 10% ethanol to gasoline will make the air much cleaner.  America now consumes more than 100 billion gallons of gasoline for transportation.  Adding 10% domestically produced ethanol to gasoline will also save billions of dollars by reducing our importation and reliance on foreign oil.  Ethanol is traditionally produced by fermenting glucose or other hexose sugars from feedstocks such as corn or sugarcane.  These feedstocks are in limited supply.  However, ethanol can also be produced from plant cellulosic biomass (corn stover, rice straw, wood, grasses, waste papers, etc.), which is not only renewable and available domestically, but also available at a low cost and in great abundance. Recently, government agencies have reported that the US has enough cellulosic biomass for the production of more than 100 billion gallons of ethanol.  Furthermore, ethanol produced from cellulosic biomass benefits greatly the environment, particularly that it will help to reduce the green house gas effect by more than 80% comparing to gasoline.

 

Cellulosic biomass is the most attractive new feedstock for the production of ethanol fuel via microbial fermentation of its sugar molecules.  However, cellulosic biomass is not as easy to convert to ethanol as traditional feedstocks such as cane sugar or corn.  For example, the polymers of sugars present in cellulosic biomass require new technologies to convert them to simple sugars such as glucose and xylose.  The main problem, however, is that there are no naturally occurring suitable microbes to convert (ferment) xylose, one of the major sugar molecules present in cellulosic biomass, to ethanol.  Fortunately, these problems have largely been solved over the past twenty years.  The culmination of this work was the genetic engineering of effective yeast to convert sugars from biomass to ethanol.

 

The goal of this website is to provide up-to-date information on the successful development of safe effective Saccharomyces yeasts to convert sugars from cellulosic biomass into ethanol. This ground-breaking work is being done by a group of scientists from Purdue University (West Lafayette Indiana), led by Dr. Nancy Ho. These yeasts can effectively convert both glucose and xylose from cellulosic biomass to ethanol in a single process.  Their yeast is currently used by Iogen, a Canadian company, to produce cellulosic ethanol (also referred to as cellulose ethanol) from wheat straw in the world’s first industrial cellulose ethanol production plant. (See Iogen press release and Purdue University news release for details).