Useful key characters separating three Aspergillus taxa: A. sojae, A. parasiticus, and A. toxicarius.

Abstract

The presence or absence of metulae, the color of conidial heads, and the pink coloring of the conidia on Czapek agar slant cultures containing 0.05 % anisaldehyde can be possibly regarded as criteria and key characters by which to distinguish three taxa, i.e., Aspergillus sojae Sakaguchi et Yamada ex Murakami, A. parasiticus Speare, and A. toxicarius Murakami. One (strain RIB 4018) of the A. toxicarius strains, producing no pink conidia, is now placed in A. parasiticus on the basis of the dark green color of conidial heads in age. A revised synoptic key is provided for the identification of the yellow-green Aspergilli which produce roughened to echinulate conidia.

Evolutionary relationships within Aspergillus section Flavi based on sequences of the intergenic transcribed spacer regions and the 5.8S rRNA gene.

“…A. toxicarius was suggested to be conspecific with A. parasiticus by Kozakiewicz (1989), which view is supported by the sequence data. Although both morphological and molecular techniques have been successfully used to distinguish A. parasiticus and A. sojae isolates (Gomi et al, 1989;Murakami et al, 1982;Yuan et al, 1995), these form a monophyletic clade together with A. toxicarius (Figs. 2 and 3).…”

Two novel aflatoxin-producing Aspergillus species from Argentinean peanuts

“…Four compounds are commonly produced in foods, aflatoxins B 1 , B 2, G 1 and G 2 , but other bio-transformed aflatoxins may occur, for example in milk, such as aflatoxins M 1 and M 2 (Cole & Cox, 1981). These mycotoxins have been shown to be produced by Aspergillus flavus, A. parasiticus (Codner et al, 1963;Schroeder, 1966), A. nomius (Kurtzman et al, 1987), A. pseudotamarii , A. bombycis , A. toxicarius (Murakami, 1971;Murakami et al, 1982;Frisvad et al, 2004) and A. parvisclerotigenus (Saito & Tsurota, 1993 in Aspergillus section Flavi, by A. ochraceoroseus (Frisvad et al, 1999, Klich et al, 2000 and A. rambellii (Frisvad et al, 2005) in Aspergillus section Ochraceorosei and in Aspergillus section Nidulantes or the ascomycete genus Emericella by Emericella astellata and E. venezuelensis (Frisvad & Samson, 2004a).…”

Comparison of the aflR gene sequences of strains in Aspergillus section Flavi

“…In particular, A. flavus and A. parasiticus have numerous phenotypic similarities to A. oryzae and A. sojae, respectively (Kurtzman et al, 1986;Klich & Pitt, 1988). The primary procedure employed to identify isolates of Aspergillus section Flavi depends on their morphologies (Murakami et al, 1982); various molecular-based methods Kumeda & Asao, 1996;Geiser et al, 1998;Lee et al, 2004) have also been used to differentiate closely related Aspergillus section Flavi strains. However, it is still difficult to identify these species.…”