Profile of a Patriot

Through the Energy Patriot, Senator Lugar profiles a student, professional, scholar, or member of the business community who has demonstrated leadership and initiative in taking concrete action to improve America's energy security. In addition to the profile posted here, individuals will receive a certificate designating them Lugar Energy Patriots, and a letter of congratulations.

Nancy Ho, Ph.D
Molecular Biologist
Purdue University’s Laboratory of Renewable Resources Engineering

Nothing is really work, the saying goes, when you enjoy your job. If that’s true, then scientist Nancy Ho has never worked a day in her life. The molecular biologist runs a genetics research group at Purdue University’s Laboratory of Renewable Resources Engineering (LORRE) integrative center for biotechnology and engineering, where she has spent her career enthusiastically developing the yeasts required to process cellulosic ethanol.

“I’ve always loved science,” says Nancy, 71. “Even as a little girl in China, I never wanted to read stories other people had written -- I wanted to dream and think about how things worked. Science was always the easiest subject for me, always so much fun. Math was my toy.”

That’s a good thing, because the process of developing efficient, biologically safe yeast to convert straw, wood chips, and corn stover into transportation fuel has taken more than twenty-five years.

Dr. George Tsao, then the director of Purdue’s LORRE, piqued Nancy’s interest in 1980 when he proposed the idea of developing a microorganism to ferment biomass. The real-world question he pitched, how to develop a genetically-engineered yeast to make the fermentation of cellulosic ethanol commercially viable, uniquely suited Nancy’s background and interest in applying recombinant DNA techniques to affect real change. Sensing the possibilities of converting agricultural wastes to ethanol, Nancy signed on to work as a scientist for LORRE immediately. “It was an exciting proposal,” commented Nancy, “and a chance to contribute to energy solutions. Genetic engineering is a very potent tool, and must be done properly with the right microbe (microorganism). I really wanted to ensure that the microbe that ultimately facilitated the production of cellulosic ethanol was safe.”

Nancy’s first grant application was so novel and well-conceptualized that it was funded immediately by the United States Department of Agriculture. But as the energy-panic of the late 1970s and early 1980s subsided, academic interest in the task diminished as well. The number of research groups worldwide attempting to engineer a yeast to ferment the different sugars in cellulosic biomass fell from more than ten in the early 1980s to just four in the 1990s. Funding became harder to find. Nonetheless, Nancy never gave up, driven at every turn by her love of science. She strongly believed she could crack the code that prevented yeast from co-converting the two major sugars in cellulosic biomass, glucose and xylose, to ethanol.

When an experiment in 1993 finally showed that Nancy’s genetically-engineered yeast had successfully fermented both sugars (a step that would dramatically reduce the cost of producing cellulosic ethanol), Nancy breathed a sigh of relief that the process she had pursued for so many years had materialized. “When it finally happened the blood rushed to my head; I thought I was having a stroke,” Nancy recalled. “I ran to the phone to call my husband and showed the results to my colleagues. I wanted to share it with everyone who had had a part in the process.”

The significance of Nancy’s success extends far beyond the satisfaction of scientific innovation. It answers a genuine need in the market for renewable fuels. Farmers in the United States produced more than four billion gallons of ethanol in 2005, primarily from corn. Yet because practical considerations limit the amount of land that can be devoted to corn, quantities of corn ethanol will never rival oil supplies. Cellulosic biomass, derived from agricultural waste products such as straw, grass and corn-stover, is less expensive and more readily available. Nancy’s genetically engineered yeast should allow producers to process ethanol from cellulosic material that can be grown anywhere as easily as from corn. Already one next-generation ethanol producer, Iogen, is working to develop the new technology into a refinery of commercial scale.

“Nancy’s distinguishing characteristic,” commented current LORRE director Dr. Michael Ladish, “is her incredible perseverance. From the beginning, she pursued the development of this yeast with single-minded purpose. It is because of her that it exists.” But more than that he says, “she brings excitement about the ramifications of her work, how many farmers it will help, jobs it will create.” It’s that passion for applied science that first brought her from China to Temple University for a Master’s Degree in organic chemistry and then to Purdue University for a Ph.D. in molecular biology.

Persistence continues to characterize Nancy and the LORRE research team. Since the initial success in 1993, LORRE scientists have made several major improvements to prepare the yeast for industrial production of cellulosic ethanol. For example, they have cloned the required genes into the yeast chromosome that has enabled the cellulose fermentation to be carried out much more easily and efficiently. Their latest innovation has been the development of yeast that produces high-value co-products that enhance other commercial products such as animal feed and detergent, in addition to producing cellulosic ethanol. This will make the production of cellulosic ethanol even more profitable and inspire more businesses and farmers to produce it.

Senator Lugar is honored to profile a talented Boilermaker scientist. We thank Dr. Nancy Ho for her contributions to a revolutionary alternative fuel and designate her the September Lugar Energy Patriot.