Skip to main content
ARS Home » Southeast Area » New Orleans, Louisiana » Southern Regional Research Center » Food and Feed Safety Research » Research » Publications at this Location » Publication #112582
Title: A NEW STERIGMATOCYSTIN-PRODUCING EMERICELLA TAXON FROM AGRICULTURAL DESERT SOILS

Author
item Klich, Maren
item MENDOZA, C - TULANE UNIVERSITY, NOLA
item Mullaney, Edward
item KELLER, N - TEXAS A&M UNIVERSITY
item BENNETT, J - TULANE UNIVERSITY, NOLA

Submitted to: Systematic and Applied Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/10/2001
Publication Date: N/A
Citation: N/A

Interpretive Summary: Proper identification of toxigenic fungi is crucial because precise identification allows researchers to predict when and if a fungus will produce a toxin harmful to man or animals. We found a fungus that did not fit the description of any know species, which consistently produced abundant amounts of the toxin sterigmatoxystin. A number of isolates of this new fungus were compared to known fungi using microscopic characters, macroscopic characters, biochemistry, and molecular analysis of the sterigmatocystin genes. We concluded that this fungus is a new variety of the fungus Emericella rugulosa, which we call variety glabra. The description of this new variety will allow researchers greater precision in identifying members of this group of species.

Technical Abstract: An unusual, sterigmatocystin-producing taxon with characteristics of both Emericella nidulans (anamorph Aspergillus nidulans) and Emericella rugulosa (anamorph Aspergillus rugulovalvus) was isolated repeatedly during a mycofloral survey of desert cotton field soils where aflatoxin is a chronic problem. Members of this taxon has ascospores with smooth convex walls like E. nidulans but grew slowly like E. rugulosa; moreover, they weere similar to an industrial echinocandin B-producing strain which had been classified as Aspergillus nidulans var. roseus. These new desert isolates were compared with A. nidulans var. roseus and representative wild-type isolates of E. nidulans and E. rugulosa using traditional morphological characters, secondary metabolite profiles of mycelial extracts, and Southern blot analysis of genomic DNA. The desert isolates and A. nidulans var. roseus shared morphological, physiological and molecular characters with E. rugulosa. These isolates constitute a new non-rugulose variant of E. rugulosa.