Genetically Engineered Saccharomyces Yeasts for Conversion of Cellulosic Biomass to Environmentally Friendly Transportation Fuel Ethanol

摘要

Ethanol is an effective, environmentally friendly, nonfossil, transportation biofuel that produces far less pollution than gasoline and contributes essentially no net carbon dioxide to the atmosphere. Furthermore, unlike crude oil for the production of gasoline, ethanol can be produced from plentiful, domestic, renewable, cellulosic biomass feedstocks. However, a major obstacle in this process is that cellulosic biomass contains two major sugars, glucose and xylose. Saccharomyces yeasts, traditionally used for large scale industrial production of ethanol from glucose, is unable to ferment xylose to ethanol. This makes the use of the safest, most effective microorganism for conversion of cellulosic biomass to ethanol economically unfeasible. In the fall of 1993, we achieved a historic breakthrough in the successful development of genetically engineered recombinant Saccharomyces yeast that can effectively ferment both glucose and xylose to ethanol. This paper provides an up-to-date overview of the design, development, and continuous innovative perfection of our recombinant Saccharomyces yeast that is widely regarded as the microorganism which will make the conversion of cellulosic biomass to ethanol commercially possible.