Developing Novel Phytase Enzymes for Animal Nutrition, Environmental
Protection, and Natural Resource Preservation
Dr. Xingen Lei, Professor of Molecular Nutrition, Department of Animal Science, Cornell University
ABSTRACT
Our goal is to develop effective phytase for improving utilization of phytate-phosphorus in animal feed and
thus reducing phosphorus pollution from animal waste. Phytase is a phosphohydrolytic enzyme to initiate
the stepwise removal of phosphate from phytate, the major form of phosphorus in plant feeds. Foodproducing animals such as swine, poultry, and the pre-ruminant calves do not have this enzyme in their
gastrointestinal tracts, and cannot digest phytate-phosphorus. Consequently, the unutilized feed
phosphorus ends up in manure and cause environmental pollution in many parts of the world. Meanwhile,
inorganic phosphorus is supplemented in diets for these animals to meet their nutrient requirements for
phosphorus. This supplementation not only accounts for the third largest expense of feed, but also
accelerates depletion of easily-accessible phosphorus deposit on earth. With the strong support of
Cornell Biotechnology Program, we have developed a new generation of bacterial phytase that has
superior optimal pH, catalytic efficiency, and proteolysis-resistance. This novel enzyme has been
commercialized worldwide by a start-up company since 2005, and has shown 2-3 times efficacy higher
than the first generation of fungal phytases. Our success helps eliminate 90,000 ton of phosphorus
excretion from animal waste in the U.S. per annum, save the feed cost of inorganic phosphorus
supplement, and preserve this non-renewable mineral that can be used up by 2082 at the current
extraction rate.
BIOGRAPHY
Xingen Lei is a full professor of molecular nutrition at Cornell University. He received his B.S. and M.S. in
China, and Ph.D. from Michigan State University. Since joining the Cornell faculty, he has pioneered in
developing a new generation of bacterial phytases and applying gene-knockout models to study
nutritional genomics of selenium. He has been an active leader in the HarvestPlus Program applying new
agriculture technologies in the global fight against human nutritional deficiencies. Lei has over 300
publications and 42 patents, advised 90 graduate students and postdoctoral fellows, and served on
scientific panels for NIH, USDA, NRC, and CAST. He is an Associate Editor of Journal of Nutrition and on
Editorial Boards for 8 International journals.