Abstract: A method for the identification of agents which inhibit chitin synthesis, thus exhibiting potential fungicidal and insecticidal activity, involves the incubation of test samples in neutral Saccharomyces cerevisiae cultures containing calcofluor white, a fluorochrome that causes lethal chitin hyper-polymerization in the yeast. Cultures containing samples that inhibit chitin synthesis exhibit enhanced growth because the growing fungus is rescued from the adverse effects of calcofluor white. In the practice of the invention, the test sample is added to a S. cerevisiae culture or culture area containing calcofluor white and the culture is incubated with the test sample for such time under such conditions sufficient to observe yeast cell growth inhibition in a corresponding culture or culture area containing calcofluor but no test sample.

Abstract: The present invention is directed to a method for screening samples for the identification of agents exhibiting potential fungicidal and insecticidal activity for a wide variety of agricultural, medical and pharmaceutical uses. The method utilizes cells that comprise a plasmid-born CTS gene of Saccharomyces cerevisiae, which allows for over expression of chitinase.