Double-stranded RNA mycoviruses in species of Aspergillus sections Circumdati and Fumigati.

Isolates (178) belonging to Aspergillus sections Fumigati, Candidi, Clavati, and Circumdati were tested for the presence of double-stranded RNA (dsRNA) genomes. Altogether, 5.6% of the Aspergillus strains examined were infected with dsRNAs.

Carbon source utilization and isoenzyme analysis as taxonomic aids for toxigenic Neosartorya species and their relatives.

Collection strains representing species belonging to the genus Neosartorya and its relatives from section Fumigati of the genus Aspergillus were compared for some of their phenotypic features. The examination of both the carbon source utilization and isoenzyme patterns provided a useful tool for clustering these strains. Many species (e.

Ochratoxin production by Aspergillus species.

Ochratoxin production was tested in 172 strains representing species in sections Fumigati, Circumdati, Candidi, and Wentii of the genus Aspergillus by an immunochemical method using a monoclonal antibody preparation against ochratoxin A. Ochratoxin A was detected in Aspergillus ochraceus, A. alliaceus, A.

Immunochemical detection of ochratoxin A in black Aspergillus strains.

One hundred and fifty-seven strains belonging to Aspergillus section Nigri were tested for ochratoxin A production using three different methods: a relatively new immunochemical method based on an enzyme-linked immunosorbent assay (ELISA), thin-layer chromatography (TLC) and high-performance liquid chromatography (HPLC). The monoclonal antibody-based ELISA technique was successfully used to screen for low levels of ochratoxin A in the black Aspergilli without concentrating the culture filtrates. The results were confirmed by TLC and HPLC analysis and chemical derivatization.

Phenotypic and genotypic analysis of variability in Aspergillus fumigatus.

Sixty-one isolates and collection strains of Aspergillus fumigatus were compared for their phenotypic (morphological features and isoenzyme profiles) and genotypic (restriction enzyme-generated mitochondrial DNA and ribosomal DNA profiles and random amplified polymorphic DNA patterns) features. The examined strains exhibited highly variable colony morphologies and growth rates at different temperatures, but their micromorphologies and conidial diameters were characteristic of the species. Of the isoenzymes studied, the beta-arylesterase and phosphatase patterns were the most divergent, and the 61 strains could be classified into seven groups.