@article{10272/28519,
year = {2026},
url = {https://hdl.handle.net/10272/28519},
abstract = {Lava tubes formed during the 2021 Tajogaite eruption on La Palma (Canary Islands, Spain) provide a rare opportunity to investigate the earliest stages of microbial colonization in a newly created subterranean volcanic environment. Although microbial communities in volcanic terrains have been widely studied, the first colonizers of newly formed lava tubes and their interactions with new mineral surfaces remain poorly understood. Here, we combined microscopy, mineralogy, stable isotope analysis, culture-dependent techniques, and 16S rRNA gene high-throughput sequencing to characterize mineral substrates, microenvironmental parameters and pioneer microbial communities 12–24 months after lava tube formation. Microbial assemblages were dominated by bacteria from the Actinomycetota, Bacillota, and Pseudomonadota phyla, together with archaea from the Methanobacteriota phylum. Organic debris from animals (notably seabirds and rodents) likely contributed to early microbial seeding and community development, as indicated by the detection of host-associated and opportunistic bacteria (e.g., Staphylococcus, Sphingomonas, Pseudomonas). Biofilm-like structures and extracellular polymeric substances were observed in association with sodium-rich sulfate and carbonate minerals, suggesting incipient microbe-mineral interactions during early mineral weathering. Archaeal-enriched communities adapted to highly saline and oligotrophic substrates (e.g., Halostagnicola, Halonotius, and Halorubrum) in some of these nascent tubes further support environmental filtering by microhabitat geochemistry and mineralogical context during early community assembly. Our findings indicate that early microbial colonization is initiated by stochastic seeding processes (via aerosols, animals, or atmospheric inputs), whereas environmental stressors related to volcanic degassing, ventilation, and extreme geochemical conditions act as strong deterministic filters that shape the final community structure in newly formed basaltic lava tubes, as reflected by the significant role of δ13C–CO2.},
organization = {Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. This work was supported by the Junta de Andalucía through the research project MICROLAVA (ref. PROYEXCEL_00185), and by the Spanish Ministry of Science, Innovation and Universities (MCIN/AEI/ https:/ /doi.or g/10.13 039/ 501100011033) under the HIRES-SOM project (ref. TED2021-130683B-723 C22), funded by the MCIN and the European Union “NextGenerationEU”/PRTR. This work was also supported by the HERMES R + D project (ref. PID2024-162087NB-C21) funded by MICIU/AEI/https://doi.org/10.13039/501100011033/, and by the ISSalus project (ref. 4000148673) funded by the European Space Agency. Additional support was provided by the Spanish National Research Council (CSIC) through the intramural project PIE_20214AT021. Part of this study was also supported by the Regional Government of the Canary Islands through the GEOPALMA research project. N.T.J.M. acknowledges funding from the Ramón y Cajal programme (RyC2021- 031253-I) of the MCIN and the European Union “NextGenerationEU”/PRTR. F.G. acknowledges support from the Ramón y Cajal contract (RYC2020- 029811-I) and the PPIT-UAL grant from the Junta de Andalucía-FEDER 2022–2026 programme (RyC-PPI2021-01). A.G-A. acknowledges funding from the MCIN and the European Union “NextGenerationEU”/PRTR under the JDC2022-049199-I contract, and from Junta de Andalucía under the DGP_POST_2024_01054 contract. A.C.P. acknowledges funding from the postdoctoral contract CEECIND/00835/2018 (doi.org/https://doi.org/10.54499/CEECIND/00835/2018/CP1580/CT0002) awarded by the Portuguese Foundation for Science and Technology (FCT) and the support by the project UID/50014/2023 (doi.org/https://doi.org/10.54499/UID/50014/2023).},
publisher = {BioMed Central},
title = {Stochastic seeding and environmental stressors as dual drivers of pioneer microbial colonization in newly formed basaltic lava tubes},
doi = {10.1186/s40793-026-00874-y},
author = {Miller, Ana Z. and Castillo Hernández, Julio Cesar and Vegas, Juana},
}