Research Features

Aspergillus species are fungi found in virtually every part of the world and they affect our lives daily. Most species are saprophytes growing on dead plant or animal tissues. Few people in the public realise that many species of these beautiful fungi are exploited to produce enzymes, drugs, organic acids and are widely used in the fermentation of various foods. Aspergillus species are also seriously damaging pre- and post-harvest plant pathogens where they can produce mycotoxins (e.g. aflatoxins, ochratoxins, fumonisins etc.), causing huge economic losses for agriculture. For example, A. fumigatus, A. flavus and A. terreus cause serious human infections while many others cause less invasive diseases.

The genus Aspergillus was described in 1729 by the Florence-based botanist Pier Antonio Micheli. To date, 1165 Aspergillus species have been described and of these 447 are included in the accepted species list curated for the genus. South Africa is considered one of the world's biodiversity hotspots. However, many fungi including Aspergillus species, remain undescribed in this area. Even though Aspergillus is commonly encountered in South Africa, most strains have remained unidentified. Where identifications have been attempted, these have been plagued by misidentifications. As such, we know very little about the species of Aspergillus occurring in South Africa.

Professor Cobus Visagie is a researcher in the Applied Mycology group at FABI. One of the group’s research goals is to discover fungal diversity in South Africa, and Cobus’ research is strongly focussed on the economically important genera Aspergillus, Penicilliumand Talaromyces. As in the case of Apergillus, the latter genera are also important for industry and agriculture.

A resource often overlooked in the process of species discovery is the value of culture collections. These repositories contain strains isolated from a wide range of substrates and ecological regions, and ideally should capture local diversity. An NRF-FBIP funded project aims to re-examine and appropriately identify all Aspergillusstrains previously accessioned in the Plant Protection Research Institute (PPRI) and Medical Research Council (MRC) collections (both housed at the Agricultural Research Council (ARC) in Roodeplaat) using modern taxonomic approaches. The ±300 strains in these collections were identified and found to represent 63 species, of which seven represented new species. These were recently published in the highly cited journal Studies in Mycology (SIM). This publication was dedicated to the globally recognised Canadian mycologist Dr Keith A. Seifert on the occasion of his retirement from Agriculture and Agri-Food Canada. Apart from Dr Seifert’s valuable contributions to the international mycological community, he has been a role model, mentor, colleague and friend to the authors on the SIM paper. This publication provides important baseline knowledge to further explore local Aspergillus diversity and how these beautiful and intriguing fungi impact the everyday lives of South Africans.