ARS | Publication request: ASPERGILLUS BOMBYCIS, A NEW AFLATOXIN PRODUCING SPECIES ASSOCIATED WITH SILKWORM REARING HOUSES IN JAPAN

Submitted to: American Society for Microbiology
Publication Type: Abstract Only
Publication Acceptance Date: June 3, 1999
Publication Date: N/A

Technical Abstract: A new aflatoxin producing species of Aspergillus, A. bombycis, was discovered during isolation of fungi from insect frass collected in silkworm rearing houses in central Japan. The new species bears a close resemblance to A. nomius. A. bombycis produces B and G aflatoxins, but is distinguished from A. nomius by different growth rates at both 37 and 42 degrees C, and by differences in the nucleotide sequences of the species in the ribosomal DNA. A. bombycis is known from four isolates, collected over a period of ten years at several silkworm rearing houses in Japan. Ribosomal DNA sequences were determined (ITS1&2, 5.8S rDNA, and 28S rDNA) and analyzed using maximum parsimony. In the most parsimonious tree, A. bombycis is related to A. nomius, and these two species form a clade. Other aflatoxigenic and non-aflatoxigenic species from Aspergillus section Flavi occur as a sister group that contains the common aflatoxin producing species A. flavus and A. parasiticus. Parsimony analysis suggests that the most recent common ancestor of species in section Flavi had aflatoxin producing ability and that the non-aflatoxin producing species have lost this biosynthetic capability.