Ticket to ride: fungi from bat ectoparasites in a tropical cave and the description of two new species

Unveiling the Subterranean Symphony: A Comprehensive Study of Cave Fungi Revealed Through National Center for Biotechnology Sequences

Caves can be regarded as extreme environments, and fungi are known as omnipresent and highly adaptable organisms that can easily colonize such environments. The primary objective of this study was to use the statistical analysis of sequences stored in the NCBI database, together with related metadata, to find and uncover statistically significant distribution patterns of fungi occupying different substrata inside the caves. The obtained list included a total of 1447 sequences corresponding to fungi isolated from various substrata within cave environments around the world, which corresponds to 445 fungal species, members of the 394 genera. Ascomycota was the most dominant phylum and Eurotiomycetes the dominant class of fungal dwellers in these environments. The highest species richness is detected for the genus Penicillium (57), followed by Aspergillus (51). On the other hand, the most frequently documented single species was Pseudogymnoascus destructans, isolated mostly from hibernating bats and guano, followed by Penicillium chrysogenum. Because caves have stable, nutrient-limited, low-competition microhabitats that support unusual or cryptic species, many new fungal taxa have been reported as well (such as Aspergillus, Apiotrichum, and Cephalotrichum species). Finally, cutting-edge molecular technologies and better sampling methods are revealing hitherto undiscovered fungal diversity in caves worldwide.

Subterranean marvels: microbial communities in caves and underground mines and their promise for natural product discovery

Covering: 2014 to 2024Since the dawn of human history, caves have played an intimate role in our existence. From our earliest ancestors seeking shelter from the elements to more recent generations harnessing cave substances for medicinal purposes, caves have served as essential resources and havens. The last 40 years of geomicrobiology research has replaced the outdated perception of subterranean environments as lifeless and unchanging with the realization that vibrant microbial communities have adapted to thrive in extreme conditions over millions of years. The ability of subterranean microbial communities to withstand nutrient deprivation and darkness creates a unique reservoir of untapped biosynthetic potential. These communities offer exciting prospects for medicine (e.g., antimicrobial and antitumor therapies) and biotechnology (e.g., redox chemical properties and biomineralization). This article highlights the significance of caves and mines as reservoirs of microbial diversity, the potential impact of their bioactive compounds on the fields of healthcare and biotechnology, and the significant challenges that must be overcome to access and harness the biotechnological potential of subterranean microbial communities. Additionally, it emphasizes the conservation efforts needed to protect these delicate ecosystems, ensuring the preservation of both ancient traditions and tomorrow's medicines.

A Review of the Biotechnological Potential of Cave Fungi: A Toolbox for the Future

The study of the intersection between biodiversity and biotechnology has revealed a rich source of innovations. Fungi, with their vast range of morphologies and lifestyles, thrive in various habitats, including caves. With impressive metabolic characteristics, they play a key role in producing essential biotechnological compounds for various economic sectors. This paper aims to consolidate evidence on the biotechnological potential of fungi isolated from caves, highlighting the urgency of conserving and exploring these ecosystems. For this purpose, we conducted a comprehensive literature search using scientific databases (SciELO, Medline Complete, Medline/PubMed, Web of Science, Scopus (Elsevier), and Google Scholar). We adopted an interdisciplinary approach by collecting information from 22 papers published between 2013 and 2024. Based on these data, our survey revealed broad potential, including antimicrobial compounds, antioxidants, antitumor agents, enzymes, and organic acids. We emphasize that accurately identifying and depositing fungal isolates in reference collections are crucial for reliable research and effective industrial applications, driving metabolic bioactivity and the production of substances with the potential to inhibit pathogens. Conserving and protecting the cave environment is imperative, considering its continuous potential for discovery and contribution to scientific advancement.

Aspergillus, Penicillium, and Talaromyces (Eurotiales) in Brazilian caves, with the description of four new species

The study of the Brazilian cave mycobiota has revealed a rich but highly diverse assemblage of fungi, with Aspergillus, Penicillium, and Talaromyces being the most frequently reported genera. The present study investigated the airborne fungi and fungi obtained from the bodies of bats, guano, and the soil/sediment from the caves Urubu (in the Atlantic Forest) and Furna Feia (in the Caatinga dryland forest) in the Northeast region of Brazil. Fungal strains were identified based on morphological features and multilocus phylogenetic analyses of ITS, beta-tubulin (BenA), calmodulin (CaM), and RNA polymerase II second largest subunit (RPB2) sequences. A total of 86 isolates were obtained, representing Aspergillus (34), Penicillium (20), Talaromyces (2), and 30 isolates belonging to other genera that will be reported on elsewhere. These isolates were identified as 18 Aspergillus, nine Penicillium, and one Talaromyces species. Eight of the species identified are reported for the first time from a cave environment. Four species showed unique morphological features and phylogenetic relationships, and are newly described. These include two new species of Aspergillus (A. alvaroi sp. nov. and A. guanovespertilionum sp. nov.), one of Penicillium (P. cecavii sp. nov.), and one of Talaromyces (T. potiguarorum sp. nov.). Our study increases the awareness and known richness of the Brazilian and global fungal diversity found in caves. Citation: Lima JMS, Barbosa RN, Bento DM, Barbier E, Bernard E, Bezerra JDP, Souza-Motta CM (2024). Aspergillus, Penicillium, and Talaromyces (Eurotiales) in Brazilian caves, with the description of four new species. Fungal Systematics and Evolution 14: 89-107. doi: 10.3114/fuse.2024.14.06.

Amphichorda monjolensis sp. nov., a new fungal species isolated from a Brazilian limestone cave, with an update on acremonium-like species in Bionectriaceae

Caves are unique environments characterized by spatial limitations, partial or total absence of direct light, and scarcity of organic carbon and nutrients. Caves are shelters for a variety of adapted animals and microorganisms such as fungi, many of which are still unknown. Amphichorda is a fungal genus belonging to the family Bionectriaceae, which includes cave-dwelling and entomopathogenic species with biotechnological applications. In this study, a new fungal species was identified using morphological and multi-locus phylogenetic analyses of the ITS, LSU, and TEF loci, in the Gruta Velha Nova limestone cave located in the Southern Espinhaço Range, Monjolos, Minas Gerais, Brazil. During the exposure of potato dextrose agar plates to the cave environment, an insect from the family Rhaphidophoridae passed by and fed on the culture medium, resulting in three fungal isolates. Phylogenetic analyses showed that these isolates formed a clade distinct from all known species, leading us to introduce a new species, Amphichorda monjolensis, which may be associated with this insect. Here, we also proposed two new combinations for species of acremonium-like fungi in the Bionectriaceae: Bulbithecium globosisporum (synonym: Acremonium globosisporum) and Hapsidospora curva (synonym: Acremonium curvum). The discovery of A. monjolensis highlights the potential of caves as shelters for new species with significant biotechnological importance.

Two new Cladosporium species from a quartzite cave in Brazil

Caves are underground and natural environments mainly found in rocky terrain. Caves have a very specific microclimate, which benefits the occurrence of specific fungi. In recent studies, researchers have observed that caves harbour a great diversity of fungi. However, studies on fungal diversity in Brazilian caves are still incipient. In September 2019, airborne spore and soil samples were collected from the Monte Cristo cave, in the Southern Espinhaço Range, Diamantina, Minas Gerais state, Brazil. Two Cladosporium single-spore isolates, among other genera, were obtained from these samples. This study aimed to characterise these two fungal isolates based on their DNA sequence data and morphology. Phylogenetic analyses of the rDNA-ITS, ACT and TEF1-α loci revealed that the isolates belonged to the Cladosporium cladosporioides species complex. Both isolates did not cluster with any known species and were formally described and named herein as C. diamantinense and C. speluncae. This study presents taxonomic novelties and contributes to the knowledge about the fungal diversity in Brazilian caves.

Eight novel cave fungi in Thailand's Satun Geopark

Karst caves are unique oligotrophic ecosystems characterised by the scarcity of organic litter, darkness, low to moderate temperatures, and high humidity, supporting diverse fungal communities. Despite their importance, little is known about the fungi in karst caves in Thailand. In 2019, we explored the culturable mycobiota associated with three selected types of substrates (air, soil/sediment and organic litter samples) from two karst caves, the Le Stegodon and Phu Pha Phet Caves, in the Satun UNESCO Global Geopark in southern Thailand. Based on morphological characters and multilocus phylogenetic analyses, eight new species (Actinomortierella caverna, Hypoxylon phuphaphetense, Leptobacillium latisporum, Malbranchea phuphaphetensis, Scedosporium satunense, Sesquicillium cavernum, Thelonectria satunensis and Umbelopsis satunensis) were described, illustrated, and compared to closely related species. These new fungal taxa form independent lineages distinct from other previously described species and classified into eight different families across six orders and two phyla (Ascomycota and Mucoromycota). This paper provides additional evidence that the karst caves located within the Satun UNESCO Global Geopark, situated in the southern region of Thailand, harbour a diverse range of newly discovered species. Citation: Preedanon S, Suetrong S, Srihom C, Somrithipol S, Kobmoo N, Saengkaewsuk S, Srikitikulchai P, Klaysuban A, Nuankaew S, Chuaseeharonnachai C, Chainuwong B, Muangsong C, Zhang ZF, Cai L, Boonyuen N (2023). Eight novel cave fungi in Thailand's Satun Geopark. Fungal Systematics and Evolution 12: 1-30. doi: 10.3114/fuse.2023.12.01.

Assessing the threat of bat-associated fungal pathogens

Fungal pathogens have become an increasingly important topic in recent decades. Yet whilst various cankers and blights have gained attention in temperate woodlands and crops, the scope for fungal pathogens of animals and their potential threat has received far less attention. With a shifting climate, the threat from fungal pathogens is predicted to increase in the future, thus understanding the spread of fungi over landscapes as well as taxa that may be at risk is of particular importance. Cave ecosystems provide potential refugia for various fungi, and roosts for bats. With their well vascularized wings and wide-ranging distributions, bats present potential fungal vectors. Furthermore, whilst bat immune systems are generally robust to bacterial and viral pathogens, they can be susceptible to fungal pathogens, particularly during periods of stress such as hibernation. Here we explore why bats are important and interesting vectors for fungi across landscapes and discuss knowledge gaps that require further research.

Unravelling the fungal darkness in a tropical cave: richness and the description of one new genus and six new species

Caves are special environments that harbour an incredible diversity of life, including fungal species. Brazilian caves have been demonstrated to be biodiversity hotspots for known and unknown fungal species. We investigated the richness of culturable fungi in a tropical cave in Brazil by isolating these microorganisms from the sediment and air. The fungal abundance of colony-forming units (CFUs) was 3 178 in sediment and 526 in air. We used morphological features and phylogenetic analyses of actin (actA), calmodulin (cmdA), internal transcribed spacer regions and intervening 5.8S rRNA (ITS), large subunit (LSU) rDNA, RNA polymerase II second largest subunit (rpb2), translation elongation factor 1-alpha (tef1), and β-tubulin (tub2) genes to identify these isolates. Forty-one species belonging to 17 genera of Ascomycota and two of Basidiomycota were identified, and the genus Aspergillus was most commonly observed in the cave (13 taxa). Twenty-four species were found in sediment (16 exclusives) and 25 species were found in air (17 exclusives). In this study, we introduced a new genus (Pseudolecanicillium gen. nov.) in the family Cordycipitaceae and six new species (14 % of the total taxa identified) of fungal isolates obtained from sediment and air: Aspergillus lebretii sp. nov., Malbranchea cavernosa sp. nov., Pseudohumicola cecavii sp. nov., Pseudolecanicillium caatingaense sp. nov., Talaromyces cavernicola sp. nov., and Tritirachium brasiliense sp. nov. In addition, we built a checklist of the fungal taxa reported from Brazilian caves. Our results highlight the contribution of Brazilian caves to the estimation of national and global fungal diversity. Citation: Alves VCS, Lira RA, Lima JMS, Barbosa RN, Bento DM, Barbier E, Bernard E, Souza-Motta CM, Bezerra JDP (2022). Unravelling the fungal darkness in a tropical cave: richness and the description of one new genus and six new species. Fungal Systematics and Evolution 10: 139-167. doi: 10.3114/fuse.2022.10.06.