Aflatoxin-producing Aspergillus species from Thailand.
Aflatoxin-producing Aspergillus species were isolated from soil samples from ten different regions within Thailand. Aspergillus flavus was present in all of the soil samples. Unlike previous studies, we found no A. parasiticus or A. flavus capable of both B- and G-type aflatoxin production in any of the samples. A. pseudotamarii, which had not been previously reported from Thailand, was found in four soil samples. In two of the samples A. nomius was determined to be the most abundant aflatoxin-producing species. Based on sequence alignments for three DNA regions (Taka-amylase A (taa), the rRNA internal transcribed spacer (ITS), and the intergenic region for the aflatoxin biosynthesis genes aflJ and aflR) the A. nomius isolates separated into three well-supported clades. Isolates from one of the A. nomius clades had morphological properties similar to those found for S-type isolates capable of B and G aflatoxin production and could easily be mistaken for these isolates. Our results suggest that such unusual A. nomius isolates could be a previously unrecognized agent for aflatoxin contamination in Thailand.
Ehrlich
Kenneth C
KC
Southern Regional Research Center\ARS\USDA, 1100 RE Lee Blvd., PO Box 19687, New Orleans LA 70124, USA. ehlich@srrc.ars.usda.gov
Kobbeman
Kerri
K
Montalbano
Beverly G
BG
Cotty
Peter J
PJ
D000348:Aflatoxins / Q000096:biosynthesis*; D001230:Aspergillus / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D015169:Colony Count, Microbial; D004271:DNA, Fungal / Q000737:chemistry* / Q000235:genetics; D015966:Gene Expression Regulation, Fungal; D010802:Phylogeny; D016415:Sequence Alignment; D012988:Soil Microbiology; D013045:Species Specificity; D013785:Thailand
D000348:Aflatoxins; D004271:DNA, Fungal