Isolation of minor aflatoxigenic fungi using dichlorvos-ammonia (DV-AM) method

Abstract

  Dichlorvos-ammonia (DV-AM) method is a sensitive detection method for aflatoxigenic fungi by distinguishing white (negative) colony and red (positive) colony. In this study, DV-AM method was applied for the isolation of aflatoxigenic fungi from soil samples from sugarcane field in Okinawa, Japan. At first screening, we isolated six positive colonies from one sample of the collected 25 independent samples. Chemical analyses demonstrated that these positive isolates could produce both B-type and G-type aflatoxins. Morphological and phylogenic analyses of two isolates (OKI-12, OKI-16) indicated that they were Aspergillus pseudonomius located in Aspergillus nomius clade. These results demonstrated that the DV-AM method is practically useful for the isolation of minor species of aflatoxigenic Aspergilli.