Preliminary Study of Cave Sample Storage Conditions on Fungal Community Diversity

Abstract

We investigated the effect of varying storage time and storage temperature on fungal species’ isolation as part of a case study of Illinois cave sediment samples. A deeper understanding of cave fungal communities may influence eco-epidemiology studies of emerging or re-emerging cave fungal pathogens. Using culture-dependent techniques, we isolated geophilic fungi from homogeneous cave sediment samples from three Illinois caves. Each sample was stored under five different temperatures ranging from −80 °C to 22 °C. Cave sediment was periodically removed at five different time periods from 48 h to 1 year, serially diluted with distilled water, lawn plated onto two different media, and monitored for fungal colonies. We isolated colonies and confirmed identity through nrDNA sequence similarity. Our results suggest that storage time was more important than storage temperature for the isolation of a wide diversity of geophilic fungal taxa. Importantly, our results show that varying storage conditions will alter both the kind of taxa and abundance of those taxa, suggesting that comparative studies of fungal diversity across studies should employ similar storage conditions. Lastly, future investigations should utilize multiple genetic markers because the fungal barcode region lacked species-level resolution for many isolates within common Illinois geophilic fungal genera.