Fungal communities in a cave of the Brazilian savannah: diversity and functional profiles in the darkness

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Cave ecosystems impose strong environmental filters, such as permanent darkness and oligotrophy, which shape microbial communities. Although fungal diversity in Brazilian caves has been increasingly reported, integrative analyses of community composition and functional structure remain limited. In this study, culture-dependent isolation (air and sediment) and ITS2 metabarcoding were combined to characterise the fungal community of Penhasco Cave, located in the Brazilian savannah (Cerrado), and to contextualise its inferred functional profile using previously published cave records from other Brazilian biomes. Across datasets, the community was dominated by Ascomycota , followed by Basidiomycota and Mucoromycota , respectively. Within Ascomycota , Sordariomycetes and Eurotiomycetes were the most representative classes. Culturable richness was higher in sediment than in air, with only two taxa shared between substrates and marked spatial turnover among sampling points. Metabarcoding reinforced the dominance of Ascomycota and detected additional lineages not recovered by cultivation. FUNGuild-based functional assignments indicated a predominance of multitrophic categories, particularly Pathotroph–Saprotroph and Pathotroph–Saprotroph–Symbiotroph modes, suggesting diverse ecological strategies. Undefined Saprotrophs were the most frequent guild, while plant-associated groups such as Plant Pathogens and Endophytes were also well represented. This pattern is consistent with the influence of allochthonous inputs from surrounding vegetation and with surface–subsurface connectivity. However, because functional assignments are based on database annotations and literature-derived genus lists, they should be interpreted as putative associations rather than direct evidence of functional activity. Overall, integrating culture-dependent and metabarcoding approaches improves the understanding of fungal diversity and functional patterns, suggesting that tropical caves may serve as reservoirs of fungal functional potential.