Bioactive potential of microbial isolates from Yoluja cave and Jepirramüin rock shelter, Cabo de la Vela (Colombia)

Authors

• Juan Sebastián López Caro, Universidad El Bosque, ColombiaFollow
• Virginia Patricia Roa Angulo, Universidad El Bosque, ColombiaFollow
• Alex Alberto González Vargas, Universidad de La Guajira, ColombiaFollow

Highlights

• First report of bioactive potential in Colombian cave microorganisms
• Yoluja and Jepirramüin differ in structure and microbial diversity
• Streptomyces isolates show broad antimicrobial activity against pathogens
• Paenibacillus extracts exhibit notable antioxidant capacity by DPPH assay
• Alta Guajira coastal caves are promising sources of bioactive compounds

Abstract

Subterranean environments harbor diverse microbial communities with significant potential for the production of bioactive compounds. This study evaluated the antimicrobial and antioxidant potential of microbial isolates obtained from Yoluja Cave and the Jepirramüin rock shelter, located in the coastal region of La Guajira, Colombia. Field sampling was conducted during three campaigns in July, September, and November 2025, including soil and surface samples collected along environmental gradients within each site. Microorganisms were isolated using selective culture media and identified through morphological and biochemical characterization. Selected strains were subjected to liquid fermentation and organic solvent extraction to obtain crude metabolites. Analysis of microbial diversity revealed greater richness and diversity in Yoluja (bacterial H′ = 1.512–1.730; S up to 14; fungal H′ = 1.190–2.002; S up to 14) compared with Jepirramüin (bacterial H′ = 0.682–1.282; S up to 9; fungal H′ = 0.983–1.882; S up to 9), suggesting that environmental complexity and nutrient availability may influence community structure. Six representative bacterial and fungal isolates, including Streptomyces, Paenibacillus, Cladosporium, and Rhizopus, were selected based on their abundance and biotechnological relevance. Antimicrobial activity was evaluated using agar diffusion assays against reference strains, with Streptomyces sp.2 exhibiting the broadest spectrum of inhibition, including activity against Staphylococcus aureus, Escherichia coli, and Candida albicans. Extracts from Paenibacillus sp.1 and Streptomyces sp.2 also demonstrated notable inhibitory effects. Antioxidant activity, evaluated using the DPPH assay, showed that all extracts exhibited free-radical scavenging capacity, with Paenibacillus sp.2 showing the highest inhibition percentage (53.47%), followed by Streptomyces spp. These findings highlight coastal cave ecosystems as reservoirs of microbial diversity with potential bioactive properties and support the exploration of understudied subterranean environments as promising sources for the bioprospecting of microorganisms with antimicrobial and antioxidant activities.

DOI

https://doi.org/10.5038/1827-806X.ijs2613

Creative Commons License

This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 4.0 License.

Recommended Citation

López-Caro, J.S., Roa Angulo, V.P., González-Vargas, A.A., 2026. Bioactive potential of microbial isolates from Yoluja Cave and Jepirramüin rock shelter, Cabo de la Vela (Colombia). International Journal of Speleology, 53(3), ijs2613. https://doi.org/10.5038/1827-806X.ijs2613