In Japan, environmental pollution caused by excrement of birds is a problem that should be solved. For example, dieback of trees and spoiling the cityscape are major problems. Birds’ dropping consists mainly of uric acid and that is really insoluble. Uric acid can be degraded to soluble material, urea. So, our goal is to catalyze uric acid to urea and make it possible to wash away dropping by rainwater. We’d like to lead our project to the solution of the pollution.Considering purine metabolism pathway, three enzymes, urate oxidase, allantoinase, allantoicase, must be synthesized to degrade uric acid to urea.