Fungi: friends or foes-an outreach science initiative for the collection of airborne fungal spores by high school students.

Fungi mostly reproduce through spores that are adapted for airborne dispersal; hence, fungal spores (and fungi) are found virtually everywhere. Fungi can be "friends or foes." Our friends include fungi used in the food and biotech industries, fungi that contribute to the cycling of carbon and nutrients, and those involved in the decontamination of polluted soils and/or water, to mention just a few examples. Many species, however, are foes-they are detrimental to plants, animals, and/or humans. Annually, >1.5 million people die due to invasive fungal infections. With the aim of enhancing microbiology literacy and the understanding of microbial concepts, we set up a project for the collection of airborne spores (the principal agent through which human airways are exposed to fungi). Students from five high schools in the Oeiras municipality partnered with us as citizen scientists; they carried out sampling by collecting fungal spores on adhesive stickers. The fungal spores collected by the students were subsequently processed in the schools and our research laboratory. Results obtained by the students themselves revealed a large variety of fungal species capable of growing in a rich medium at 30°C. In the research laboratory, using selective isolation conditions, 40 thermotolerant fungi were isolated, 32 of which were taxonomically identified as aspergilla, mostly from within the Aspergillus fumigatus taxa, yet exhibiting high genetic heterogeneity. The protocols and results were presented to the students, who were made aware of the local dispersal of airborne fungal spores, including some from potentially pathogenic fungi. Through carrying out scientific activities, the students developed both the interest and the self-confidence needed to implement future environmental investigations.