A new sterigmatocystin-producing Emericella variant from agricultural desert soils

An unusual, sterigmatocystin-producing taxon with characteristics of both E mericella nidulans (anamorph Aspergillus nidulans) and Emericella rugulosa (anamorph Aspergillus I rugulovalvus, formerly A. rugulosus) was isolated r epeatedly during a mycofloral survey of desert cotton field soils where afl atoxin is a chronic problem. Members of this taxon had ascospores with smoo th convex wails like E. nidulans but grew slowly like E. rugulosa; moreover , they were 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 w ild-type isolates of E, nidulans and E. rugulosa using traditional morpholo gical characters, secondary metabolite profiles of mycelial extracts, and S outhern blot analysis of genomic DNA. The desert isolates and "A. nidulans var. roseus" shared morphological, physiological and molecular characters w ith E. rugulosa. These isolates constitute a new non-rugulose variant of E. rugulosa.