TOPIC: Aeromycology: research progress and future challenges
Ioanna Pyrri is an academic mycologist at the National and Kapodistrian University of Athens, in Greece. Along with research activity, she teaches mycology in undergraduate and graduate students.She is also the Curator of micromycetes of the ATHUM Culture Collection of Fungi, included in the ATHUM Mycetotheca. She has a long-standing experience on the study of airborne fungi in outdoor and indoor air in diverse environments with culture-based and culture independent methods.
Her research focuses on the diversity, abundance and fluctuations of fungi in the air with classical methods and implementation of molecular tools. The 25-year study has resulted in the enrichment of the ATHUM Culture Collection of Fungi with several hundreds of fungal strains originating from the ambient and indoor air. Ioanna has received by the IAA in 2006 the Young Aerobiologists Award, for her contribution to aerobiology.
ABSTRACT:
The fungi are omnipresent, abundant constituents of virtually all ecosystems on Earth. They serve diverse functions exhibiting an unusually high degree of pleiomorphism and have evolved to utilize air as their key dispersal medium. The role of airborne fungi is of much concern for human affairs. The interest for their study was triggered by phytopathogenic and allergenic fungi and nowadays has been expanded to fungi in houses, working environments and schools for well-being of occupants, in hospitals for detecting infectious agents, in industries for safety of products, in libraries, museums and galleries for protection of cultural heritage, in ambient air for air quality and correlation to pollution, in natural processes for biometeorology, etc.
A systematic study of airborne fungi was launched in early 20th century, although their presence in the air has been documented much earlier. The gravitational method on glass slides or petri plates were originally used. It was the mycologist J. Hirst who recognized the need for a volumetric sampler with time resolution and engineered in 1952 the first spore-trap slit impactor that is widely used until today. The development of several samplers were based on trapping of fungal spores either on adhesive surfaces for direct identification or on nutrient media for recovering fungi. The two strategies are complementary, but each one has limitations that even their combination cannot eliminate. The advent of genetic analysis revolutionized aeromycological studies. Molecular tools were employed in order to contribute to accurate identification of common species in the air, in large genera like Aspergillus, Cladosporium, Penicillium or non-sporulating fungi. Furthermore, the high throughput sequencing enabled the direct analyses of environmental DNA originating from the air revealing a wealth of fungal diversity dominating the atmosphere and in much higher concentrations than anticipated. Metagenomics, metatrascriptomics and metabolomics are very promising for aeromycological studies. In addition, sampling devises have been developed which are able to detect, analyze and identify airborne fungal spores and pollen by light scattering, laser-induced fluorescence or holography, using signal or image processing in order to classify spores in real time or near real time.
A plethora of fungal species has been documented in the air worldwide, both outdoors and in diverse constructed habitats. Nonetheless, our knowledge of their occurrence in air is still incomplete, due to the difficulty in identification and to the dissimilarity of investigation methods. For monitoring and development of a world net on airborne fungi, there is an urgent need for standardization of methodology based on classical and modern methods. This can be achieved by collaboration of research groups moving toward complementary practices. An holistic approach incorporating additional evidence into existing knowledge will advance aeromycology in a new era.