New automated system for evaluating urease inhibitors

Urease enzymes occur widely in nature, such as in soil and in some pathogenic microorganisms, being responsible for accelerating the rate of urea hydrolysis by a hundred trillion times. Thus, the development of new urease inhibitors (UI) is essential for medicine and agriculture1. In this work we developed a system for screening new UIs using the closed continuous airflow method2. A device coupled to the volatilization system provides a trend graph that demonstrates how long an inhibitor can delay ammonia volatilization, with reference to N-(n-butyl)thiophosphoric triamide (NBPT), the most commonly used UI in agriculture3. By defining a metric based on light intensity and assessment time, we established the endpoints for urea (6:01:29 ± 0:35:27 h); for the NBPT (2:07:30 ± 4:44:33 h); and for 3 unpublished UIs (5D9, 2B10, 5D10), which were, respectively, 9:07:43 ± 0:16:51 h; 11:36:34 ± 2:18:51 h and 9:27:31 ± 0:39:57 h.