Submitted to: American Society for Microbiology Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: April 1, 2004
Publication Date: June 1, 2004
Citation: Ehrlich, K., Montalbano, B.G., Kobbeman, K., Cotty, P.J. 2004. Aflatoxin-producing Aspergillus species from Thailand. Proceedings of American Society for Microbiology Annual Meeting. O-015:463. Technical Abstract: Aflatoxin-producing Aspergillus species were isolated from soil samples from ten different regions within Thailand. A. flavus strain SB and L isolates were present in soil samples from all of the regions. A. pseudotamarii, which had not been previously reported from Thailand, was found in four soil samples. In soil samples from two of the regions, A. nomius isolates constituted 40% of the total isolates. These produced large amounts of both B and G aflatoxins, and based on DNA sequence alignments for genes for Taka-amylase, the rRNA internal transcribed spacer (ITS), and the intergenic region for two genes involved in regulation of aflatoxin biosynthesis, aflJ and aflR, the A. nomius isolates separated into three well-supported clades. The presence of slightly different transcription factor-binding elements within the aflJ-aflR intergenic region DNA from isolates of the different clades suggests that these A. nomius isolates are differentially regulated by developmental and nitrogen regulatory transcription factors. An examination of over 200 isolates failed to detect any A. flavus isolates capable of both B and G aflatoxin production. Our results suggest that A. nomius may be an important etiological agent for aflatoxin contamination of crops in Thailand.