Diagnostic tools to identify black aspergilli.

The present taxonomy of the black aspergilli reveals that there are 19 accepted taxa. However the identification of species of Aspergillus section Nigri is often problematic in spite of the existence of numerous methods proposed. An overview is provided of phenotypic and molecular methods to identify the accepted species of the black aspergilli. Colony morphology, conidial size and ornamentation of the ex type cultures is presented in a pictorial overview. The temperature range of all species is given and their growth characteristics on creatine agar and boscalid agar, a medium which was developed as a selective medium for the isolation of A. carbonarius are also shown. The extrolites produced by each species are listed while the response of the Ehrlich reaction is described. The literature on the various molecular methods to be used for species identification is reviewed and a critical evaluation of the usefulness of various techniques and genomic loci for species identification of black aspergilli is presented.