SEAMEO BIOTROP featured Prof Robert A. Samson from Westerdijk Fungal Biodiversity Institute, Utrecht, the Netherlands, in its third Quarterly Public Seminar 2018 to present a lecture on ‘The Current Status of Taxonomy and Biodiversity of Toxigenic Fungi’. This seminar was held on 30 August 2018 at the Centre’s headquarter in Bogor, attended by 75 participants from various research and government institutions, universities and companies.
Prof Robert began his presentation with a note about the importance of proper fungal recognition and identification. Even though many species are beneficial for other living organisms, especially human, he said that the number of toxic fungi is also abundant. Several genera of phylum Ascomycota, namely Aspergillus, Penicillium, Fusarium and Talaromyces, are well-known to produce important mycotoxins such as aflatoxins, trichothecenes, ochratoxins, patulin and sterigmatocystin which affect the foods negatively. Fungal contamination on foods by these fungi through spoilage or presence of mycotoxins is still considered as a major problem causing extensive loss. Fortunately, he said, the fungal identification process is currently facilitated by a wealth of available data on the growth, distribution and possible production of toxic metabolites of the known food-borne species, thus, limiting any possible harm that may occur.
The taxonomy of the food-borne fungi has been based on phenotypic characters for many years, with the exception of yeasts, where physiological characters are frequently applied. Prof Robert stated that problems in species delimitation based on morphology occur in several known toxigenic species, where morphology and molecular data are not congruent. In this molecular era, the molecular tools are considered as the first DNA barcode for fungi. Identification which only uses this kind of tools is also not simple and often does not give a good species recognition since other loci for each genus have to be applied to reach the precise identification. Therefore, current fungal taxonomic research often uses a polyphasic approach combining phenotypic, genotypic and chemical characters to produce better identification results. Particularly in the last ten years, the taxonomic and phylogenetic studies have increased and demonstrated that many well-known species are in fact representing cryptic taxa.
Prof Robert also presented the new taxonomies in important fungal genera along with the significance of the species and its properties using the polyphasic species concept. For example, a new taxonomic scheme of section Circumdati (yellow Aspergilli) which produces ochratoxin shows that the number of species is now more than 27 and not 8 species anymore. Besides the robust phylogenetic analyses which elucidate species delimitation, the data show that each species has a specific metabolite profile.
As a conclusion, Prof Robert conveyed the increase of the food-borne mycobiota biodiversity due to new taxonomic insights which give a more refined species delimitation. He also suggested all food mycologists to follow the current taxonomic schemes because correct species identification is still essential in tackling the problems of contamination of food and the possible production of mycotoxins.
Prof Robert A. Samson is affiliated with the Dutch Species Register as a fungal specialist. He has been working at the Westerdijk Fungal Biodiversity Institute in Utrecht, the Netherlands, since 1970. In 1983 he became the Head of the Department of Services and Applied Research in the same institution and he formally retired on 01 April 2011. His expertise in food-borne fungi such as Penicillium and Aspergillus leads him to be still active as Emeritus Senior Researcher of Applied and Industrial Mycology research group. He has also been appointed as Adjunct Professor at the Kasetsart University in Bangkok, Thailand, since 2002 and at the Portuguese Open University in Lisbon, Portugal, since 2009. To date, he has published 43 books in which his first book, together with Garry Cole, is a classical mycological publication describing the conidial ontogeny of Hyphomycetes.
Prof Robert A. Samson is currently the Secretary General of the International Union of Microbiological Societies. In addition, he is also an Executive Editor of an international scientific journal, namely Studies in Mycology, and a member of various scientific organizations, including the British Mycological Society, the American Mycological Society, the World Federation of Culture Collections, and the International Union for Microbiological Societies.
Throughout his outstanding career in mycological research, Prof Robert A. Samson has received many honours, including recipient of the USFCC/J. Roger Porter award by the American Society of Microbiology, an honorary membership in the Hungarian Society for Microbiology and the Mycological Society of America, an honorary degree from the Swedish University of Agricultural Sciences, and the de Bary Medal from the International Mycological Association.