# Airborne Fungi in Show Caves from Southern Spain
## 4 Discussion
### Fungal Ecology
_Leptobacillusum symbioticum_ was predominant in winter in all the rooms of Gruta de las Maravillas, except in Sala de las Conchas, and appeared in a few rooms in summer (Sala de las Conchas) and Sala del Lago 2 in autumn. This fungus was also present in all the show rooms in Cueva del Tesoro. _Leptobacillusum leptobactrum_ was identified in Cueva de Ardales (Sala de las Estrellas), in spring and winter. In Gruta de las Maravillas (Sala del Volcan), both _L. symbioticum_ and _L. leptobactrum_ amounted 100% of the fungi isolated in winter. _Leptobacillusum leptobactrum_ was previously recorded as _Verticillium leptobactrum_, in the air of Lascaux, a cave densely populated by arthropods [2, 9, 27]. The abundance of the genus _Leptobacillium_ in winter may be due to the fact that their species are parasitic of mites [25] and leptodopteran larvae and pupae [26], coinciding with the fact that most troglobiles species enter a dormant state in the winter season. The entomopathogenic _Beauveria bassiana_ is found naturally in soils and on insects and mites, with the capacity to infect different species, which is why it is widely used for pest control [28]. This species was identified in the end of the stair in Cueva de Ardales in spring and summer samplings and in Cueva del Tesoro in winter (Sala de la Virgen). It has also been recorded in Lascaux Cave [2], and Domica Cave [21]. An additional and single record of entomopathogenic fungus was _Lecanicillium tenuipes_, majority in Cueva del Tesoro, Sala de Lagos, in summer. This species was isolated from different insects [29, 30]. _Schizophrenia commune_ was one of the most abundant fungus in Cueva del Tesoro, (Sala de la Virgen, Sala de Lagos) and outdoor in spring, and in Sala de Marco Craso in summer. This basidiomycete is a saprophytic fungus that grows on decaying plants or wood [31]. The presence of basidiomycetes is usually common in caves [11, 21] and could be associated with the presence of structures and/or wood fragments, common in caves, such as Altamira, Nerja, etc. Therefore, the presence of _S. commune_ in Sala de la Virgen, could be attributed to the wooden platform found in this room, although their transport from outdoor cannot be discarded due to the proximity of this room to the entrance. The genera _Aspergillus_ and _Penicillium_ were the most abundant in Cueva de Nerja [12]. This trend was also found in Cueva del Tesoro, located some 40 km from Nerja. Four _Aspergillus_ species, _A. versicolor_, _A. thesauricus_, _A. nidulans_ and _A. parasiticus_, were retrieved in this cave. _Aspergillus thesauricus_ was described from strains isolated for the first time in Cueva del Tesoro [32]. A few _Penicillium_, _P. citrenoirum_, _P. lanosum_, _P. consorbrium_, and _P. chrysogenum_ were found in Cueva del Tesoro, whereas _P. chrysogenum_, _P. minioluteum_, _P. flavigenum_, and _P. brevocompatum_ were isolated from Gruta de las Maravillas; where _P. chrysogenum_ reached an abundance of 82.7% in Sala de los Desnudos. Cueva de Nerja and Cueva del Tesoro, in addition to the short distance from one to another, have in common the presence of abundant phototrophic biofilms on the speleothems and walls due to the artificial lighting installed for facilitating the visits. The abundance of these two genera could be related with the cyanobacteria and algae biofilms populating the two caves. [PERSON] et al. [33] and [PERSON] et al. [34] found a close association between _Aspergillus_ and _Penicillium_ spp. and cyanobacterial biofilms. It should be noted the presence of yeasts of the genera _Cutaneousotrichosporon_, _Trichosporon_, _Cryptococcus_, _Naganishia_, _Cystobasidium_, _Microstroma_ and _Phragmotaneinum_ in Gruta de las Maravillas and their absence in the other two caves could be related to the high number of visitors. The presence of yeasts in the caves was related with the frequentation of people and animals [35]. _Cutaneousotrichosporon_, _Trichosporon_ and _Cryptococcus_ species have been isolated from bat guano in caves in Japan [36; 37].