Aspergillus flavus Group Fungi Isolated from Japanese Tea Fields

Abstract

Soil samples from the tea fields located from the central to southern parts of Japan were surveyed for Aspergillus fungi. Sixty three soil samples from 13 prefectures were examined using Aspergillus Flavus/Parasiticus Agar and Dichloran Rose-Bengal Chloramphenicol media that are selective for Aspergillus fungi. In 11 soil samples from 7 prefectures, Shizuoka, Mie, Siga, Kochi, Fukuoka, Nagasaki, and Miyazaki, 27 strains of A. Favus group fungi were isolat-ed. Among these, 4 isolates from 3 prefectures, Mie, Kochi and Miyazaki, produced aflatoxins. One of these isolates from Miyazaki prefecture produced more than 10 ppm of aflatoxin B₁ in a liquid medium. Twenty one isolates from 6 prefectures produced cyclopiazonic acid (CPA). Several of these isolates produced more than 5 ppm of CPA in a liquid medium.