Unveiling the menace of lampenflora to underground tourist environments

13 páginas.- 6 figuras.- 3 tablas.- 59 referencias

Permanent artificial lighting systems in tourist underground environments promote the proliferation of photoautotrophic biofilms, commonly referred to as lampenflora, on damp rock and sediment surfaces. These green-colored biofilms play a key role in the alteration of native community biodiversity and the irreversible deterioration of colonized substrates. Comprehensive chemical or physical treatments to sustainably remove and control lampenflora are still lacking. This study employs an integrated approach to explore the biodiversity, eco-physiology and molecular composition of lampenflora from the Pertosa-Auletta Cave, in Italy. Reflectance analysis showed that photoautotrophic biofilms are able to absorb the totality of the visible spectrum, reflecting only the near-infrared light. This phenomenon results from the production of secondary pigments and the adaptability of these organisms to different metabolic regimes. The biofilm structure mainly comprises filamentous organisms intertwined with the underlying mineral layer, which promote structural alterations of the rock layer due to the biochemical attack of both prokaryotes (mostly represented by Brasilonema angustatum) and eukaryotes (Ephemerum spinulosum and Pseudostichococcus monallantoides), composing the community. Regardless of the corrosion processes, secondary CaCO3 minerals are also found in the biological matrix, which are probably biologically mediated. These findings provide valuable information for the sustainable control of lampenflora.

This work received support from the Spanish Ministry of Science and Innovation (MCIN) under the research project TUBOLAN PID2019-108672RJ-I00 funded by MCIN/AEI/https://doi.org/10.13039/501100011033. The financial support from the Portuguese Foundation for Science and Technology (FCT) under the MICROCENO project (https://doi.org/10.54499/PTDC/CTA-AMB/0608/2020) is also acknowledged. This work was partly funded by University of Salerno (Italy) within the ORSA197159 and ORSA205530 projects. The support from the intramural project PIE_20214AT021 funded by the Spanish National Research Council (CSIC) is also acknowledged. A.Z.M. was supported by a Scientific Employment Stimulus (CEEC) contract (CEECIND/01147/2017) awarded by FCT and then a Ramón y Cajal contract (RYC2019-026885-I) from the MCIN. The authors are grateful to MIdA Foundation, manager of the Pertosa-Auletta Cave, and to the speleo-guide Vincenzo Manisera for the support.

Peer reviewed