Background: Microorganisms are present throughout the environment and play a very important role in different ecosystems, including soil functions and composition. The presence of fungi in sludge raises concerns about potential skin infections or allergies if they come into contact with the skin. This is a mud-filled volcanic cone located in the rural area of the municipality of Santa Catalina in the Caribbean Region of Colombia, at coordinates (10°44´40´´ N and 75°14´29´´ W). The objective of this study was to identify filamentous fungi present in liquid and dry sludge from El Totumo volcano.
Methods: Plates were prepared with SDA, RBA, and Mycosel culture media. For sample analysis, one gram of each sample was weighed in triplicate and spread onto each plate. The plates were incubated for 7 to 14 days at 25°C. The species were then transferred to tubes containing the same culture medium and incubated for 7 days at the same temperature. Species were identified by their microscopic and macroscopic characteristics. Colonies (CFU) were counted, and the average was obtained for each medium. For the microscopic sample, they were transferred to a slide containing lactophenol and observed under a microscope. Taxonomic keys were used.
Results: The average number of colonies in the sludge was 25 CFU in the dry sludge and 44 CFU in the liquid sludge. Six genus were identified in the taxonomic analysis: Aspergillus, Penicillium, Trichoderma, Fusarium, Culvularia, and Rhizopus. Six fungal species were isolated from the liquid sludge: Rhizopus, Aspergillus fumigatus, Aspergillus glaucus, Aspergillus flavus, Penicillium sp., and Aspergillus terreus. Seven fungal species were isolated from the dry sludge: Aspergillus niger, Culvularia, Fusarium, Aspergillus flavus, Trichoderma, Penicillium sp. and Aspergillus terreus. The fungal genus with the most species identified was Aspergillus.
Conclusion: More colony and species growth were found in the liquid mud than in the dry mud. Most of the isolated fungi represent skin and respiratory diseases that can affect humans. Understanding these findings is critical to preventing potential illnesses in visitors to this site.
mud, filamentous fungi, volcano, microorganisms
Ameen, M. (2010). Epidemiology of superficial fungal infections. Clinics in dermatology, 28(2), 197-201. https://doi.org/10.1016/j.clindermatol.2009.12.005.
Arastehfar, A., Carvalho, A., Houbraken, J., Lombardi, L., García Rubio, R., Jenks, J. D., Hoenigl, M. (2021). Aspergillus fumigatus and aspergillosis: From basics to clinics. Studies in Mycology, 100, Article 100115. https://doi.org/10.1016/j.simyco.2021.100115.
Berger, S. (2015). Infectious diseases of Puerto Rico. GIDEON e-book series. ISBN 978-1-4988-0599-5.
Brandão, J., Rosado, C., Silva, C., Alves, C., Almeida, C., Carrola, C., ... & Rosado, L. (2007). Monitorização da qualidade das areias em zonas balneares: relatório. https://repositorio.insa.pt/entities/publication/35381d2a-3959-4b53-966d-d17a00b7abb3.
Brandão, J., Wergikosky, B., Rosado, C., Noronha, G., Rosado, L., Veríssimo, C., ... & Rebelo, H. (2002). Qualidade Microbiológica de Areias de Praias Litorais: relatório final. https://core.ac.uk/outputs/70638653/?source=oai.
CNN en Español. (2024). ¿Qué son los volcanes de lodo y qué riesgos presentan?
de Mesquita, C. P. B., Vimercati, L., Wu, D., Childress, M. K., Danz, A., Grupe, A. C., ... & Quandt, C. A. (2024). Fungal diversity and function in metagenomes sequenced from extreme environments. Fungal Ecology, 72, 101383. https://www.sciencedirect.com/science/article/pii/S1754504824000540?via%3Dihub.
Dill, H. G., & Kaufhold, S. (2018). The Totumo mud volcano and its near-shore marine sedimentological setting (North Colombia)—From sedimentary volcanism to epithermal mineralization. Sedimentary Geology, 366, 14-31. https://doi.org/10.1016/j.sedgeo.2018.01.007.
Dishliyska, V., Miteva-Staleva, J., Gocheva, Y., Stoyancheva, G., Yovchevska, L., Abrashev, R., ... & Krumova, E. (2025). Biological Potential of Extremophilic Filamentous Fungi for the Production of New Compounds with Antimicrobial Effect. Fermentation, 11(6), 347. https://doi.org/10.3390/fermentation11060347.
Echevarría, L. (2019). Preliminary study to identify filamentous fungi in sands of three beaches of the Caribbean. PSM Microbiology, 4(1), 1-6. https://psmjournals.org/index.php/microbiol/article/view/278.
Echevarría, L. (2022). Inventory of filamentous fungi and yeasts found in the sea water and sand of the beach of pier in Arecibo Puerto Rico. PSM Microbiology, 7(1), 4-11. https://psmjournals.org/index.php/microbiol/article/view/602.
Echevarría, L., & Bello, F. (2025). Variety of Filamentous Fungi and Yeast Species Found on the White Sands of Crystal Beach in the Bahamas: Swimming with the Pigs. PSM Microbiology, 10(1), 1-10. https://psmjournals.org/index.php/microbiol/article/view/785.
EFE:Verde. (2015). El volcán del Totumo, salud y ecoturismo en el norte de Colombia.
Flores-Amaro, O. A., Ramos-Gómez, M. S., Guerrero-Barrera, A. L., Yamamoto-Flores, L., Romo-Rodríguez, P., Mitchell, K., & Avelar-Gonzalez, F. J. (2024). Characterization and evaluation of the bioremediation potential of Rhizopus microsporus Os4 isolated from arsenic-contaminated soil. Water, Air, & Soil Pollution, 235(8), 529. https://doi.org/10.1007/s11270-024-07232-z.
Goel, S., & Bhardawaj, A. (2014). A study of environmental and health benefits of mud and clay. Nature & Environment, 19(2), 202–206.
González, J., & Guzmán, D. (2019). Estudio paleopalinológico y reconstrucción de la vegetación en áreas de depósito de lodos volcánicos en Armero‑Tolima.
Gostinčar, C., & Turk, M. (2012). Extremotolerant fungi as genetic resources for biotechnology. Bioengineered, 3(5), 293-297. https://www.tandfonline.com/doi/full/10.4161/bioe.20713.
Harman, G. E. (2006). Overview of Mechanisms and Uses of Trichoderma spp. Phytopathology, 96(2), 190-194. https://apsjournals.apsnet.org/doi/10.1094/PHYTO-96-0190.
Hmad, I. B., & Gargouri, A. (2024). Halophilic filamentous fungi and their enzymes: potential biotechnological applications. Journal of Biotechnology, 381, 11-18. https://doi.org/10.1016/j.jbiotec.2023.12.008.
Isola, D., & Prenafeta-Boldú, F. X. (2025). Diversity and Ecology of Fungi from Underexplored and Extreme Environments. Journal of Fungi, 11(5), 343. https://doi.org/10.3390/jof11050343.
Latgé, J. P., & Chamilos, G. (2019). Aspergillus fumigatus and Aspergillosis in 2019. Clinical microbiology reviews, 33(1), 10-1128. https://doi.org/10.1128/CMR.00140-18.
Robledo-Mahón, T., Calvo, C., & Aranda, E. (2020). Enzymatic potential of bacteria and fungi isolates from the sewage sludge composting process. Applied Sciences. 10(21), 7763. https://doi.org/10.3390/app10217763.
Stępień, Ł. (2020). Fusarium: Mycotoxins, taxonomy, pathogenicity. Microorganisms, 8(9), 1404. https://doi.org/10.3390/microorganisms8091404.
Stępień, Ł. (2023). Plant-pathogenic fusarium species. Journal of Fungi, 9(1), 13. https://doi.org/10.3390/jof9010013.
Wang, X, Pecoraro L. (2021)b. Diversity and Co-Occurrence Patterns of Fungal and Bacterial Communities from Alkaline Sediments and Water of Julong High-Altitude Hot Springs at Tianchi Volcano, Northeast China. Biology, 10(9),894. https://doi.org/10.3390/biology10090894.
Wang, X., & Pecoraro, L. (2021)a. Analysis of Soil Fungal and Bacterial Communities in Tianchi Volcano Crater, Northeast China. Life, 11(4), 280. https://doi.org/10.3390/life11040280.
Warnock, D. W., Hajjeh, R. A., & Lasker, B. A. (2001). Epidemiology and prevention of invasive aspergillosis. Current Infectious Disease Reports, 3(6), 507-516. https://doi.org/10.1007/s11908-001-0087-3.
