The U.S. Patent Office has granted a patent (#7309505) to two scientists, Drs. Edward Mullaney and Abul Ullah, of the Commodity Utilization Research Unit of the Southern Regional Research Center on December 18, 2007. The patent is titled "Using mutations to improve Aspergillus phytases" and is shared with Prof. Xingen Lei of Cornell University. The ARS scientists have modified the fungal phytase through site-directed mutagenesis to improve the functionality of a fungal phytase. The Cornell team did the field studies with mutant phytases to show that the modified phytase performed better as expected than the native enzyme when ingested by pigs. The market for phytase is about $500 million and growing. The developed nations first used the fungal phytase since mid 1990s to combat phosphate pollution in the farmland. Now the emerging nations such as China and India are poised to use the enzyme to improve the nutritional value of soybeans and wheat and to protect the environment. Some nutrition experts believe that phytase when added to foodstuffs may relieve iron deficiency in humans. The primary usage is however in poultry and swine farms to reduce phosphate pollution. The ARS started the work on phytase in 1984-85 in New Orleans. The SRRC scientists are in the forefront of phytase research. They first purified, biochemically characterized, and cloned a fungal phytase that became the benchmark enzyme. Later, a Dutch enzyme producer (Gist-brocade) commercialized the phytase production in Europe. The European patent on phytase granted to Gist-brocade was revoked in 2000 because of the obviousness of cloning phytase based on information published by Dr. Ullah. The patent granted to the SRRC scientists is the first improved version of the native enzyme obtained via knowledge-based protein engineering.