Emericella venezuelensis, a new species with stellate ascospores producing sterigmatocystin and aflatoxin B-1

Emericella venezuelensis is a new species, differing from two other species with stellate ascospores, E. variecolor and E. pluriseminata, by triangular flaps on the convex sides of the ascospores, and further from E. variecolor by producing an Aspergillus anamorph only on unconventional growth media.

The three species also differ in their profiles of extrolites (secondary metabolites). Emericella venezuelensis produces aflatoxin B-1, sterigmatocystin, and terrein and compounds with chromophores of the shamixanthone, emerin and desertorin type of compounds. F. variecolor produces asteltoxin, shamixanthone, asperthecin, and terrein, in addition to metabolites unequivocally recorded in the literature or tentatively identified here as astellolide A & B, andibenin A, B, C, andilesin A, B, C, anditomin, astellatol, stellatic acid, stellatin, tajixanthone, radixanthone, najamxanthone, ajamxanthone, variecoxanthone A, B, C, isoemericellin, kojic acid, varitriol, varioxiran, dihydroterrein, 7-hydroxyemodin, avariquinone and stromemycin.

E. pluriseminata produces several unknown specific extrolites. E. venezuelensis is the first organism of marine origin reported to produce aflatoxin. Aflatoxin production by E. venezuelensis makes this species an attractive model organism for the study of the regulation of this important type of carcinogenic mycotoxins in combination with the knowledge on sterigmatocystin production by E. nidulans, soon to be whole genome sequenced.

The isolates were also analyzed cladistically using partial sequences of the beta-tubulin gene. Since three species of Emericella have stellate ascospores, and the type material of E. variecolor is equivocal, this species is epitypified with CBS 598.65. Emericella species normally do not appear to cause problems for food safety, as they are most often found in litter and soil.