Análisis geoambiental en medios hipogeos

8 páginas, 1 figura. Ed. Miguel Ángel Rogerio Candelera y Cesáreo Sáiz Jiménez. Primera Reunión de la Red de Ciencia y Tecnología para la Conservación del Patrimonio (Madrid, 28-29 de junio de 2011).Los coordinadores de los dos grupos de trabajo localizados actualmente en dos instituciones independientes (CSIC, Universidad de Alicante) se iniciaron científica y profesionalmente en el equipo de investigación de Geología - Geoquímica - Microclima aplicados a la Conservación del Patrimonio que se formó bajo la dirección de Manuel Hoyos Gómez a principios de la década de los 90. En el campo de la Conservación del Patrimonio, las investigaciones de ese grupo se centraron especialmente en la protección del arte rupestre y actualmente se enfocan al estudio integrado de ambientes subterráneos (cuevas, catacumbas,túneles, etc.) y de los procesos de deterioro del patrimonio que albergan. Los proyectos en los que los dos grupos trabajan abitualmente en estrecha relación incluyen datos de los parámetros climáticos y microclimáticos que caracterizan los sitios de estudio, de las características mineralógicas, geoquímicas y petrofísicas de los soportes y de las aguas de infiltración, y de los aspectos geomicrobiológicos de la interacción entre microoorganismos y los diferentes sustratos existentes (rocas, materiales de construcción, espeleotemas, etc.).Peer reviewe

New insights into the structure, microbial diversity and ecology of yellow biofilms in a Paleolithic rock art cave (Pindal Cave, Asturias, Spain)

In the absence of sunlight, caves harbor a great diversity of microbial colonies to extensive biofilms with different sizes and colors visible to the naked eye. One of the most widespread and visible types of biofilm are those with yellow hues that can constitute a serious problem for the conservation of cultural heritage in many caves, such as Pindal Cave (Asturias, Spain). This cave, declared a World Heritage Site by UNESCO for its Paleolithic parietal art, shows a high degree of development of yellow biofilms that represents a real threat to the conservation of painted and engraved figures. This study aims to: 1) identify the microbial structures and the most characteristic taxa composing the yellow biofilms, 2) seek the linked microbiome reservoir primarily contributing to their growth; 3) seed light on the driving vectors that contribute to their formation and determine the subsequent proliferation and spatial distribution. To achieve this goal, we used amplicon-based massive sequencing, in combination with other techniques such as microscopy, in situ hybridization and environmental monitoring, to compare the microbial communities of yellow biofilms with those of drip waters, cave sediments and exterior soil. The results revealed microbial structures related to the phylum Actinomycetota and the most characteristic bacteria in yellow biofilms, represented by the genera wb1-P19, Crossiella, Nitrospira, and Arenimonas. Our findings suggest that sediments serve as potential reservoirs and colonization sites for these bacteria that can develop into biofilms under favorable environmental and substrate conditions, with a particular affinity for speleothems and rugged-surfaced rocks found in condensation-prone areas. This study presents an exhaustive study of microbial communities of yellow biofilms in a cave, which could be used as a procedure for the identification of similar biofilms in other caves and to design effective conservation strategies in caves with valuable cultural heritage.This research was supported by the Spanish Ministry of Science and Innovation through project PID2019-110603RB-I00 and the collaboration of PID2020-114978GB-I00 project, MCIN/AEI/FEDER, UE/10.13039/501100011033. This is a contribution from CSIC Interdisciplinary Thematic Platform Open Heritage: Research and Society (PTI-PAIS)

Role of subterranean microbiota in the carbon cycle and greenhouse gas dynamics

Subterranean ecosystems play an active role in the global carbon cycle, yet only a few studies using indirect methods have focused on the role of the cave microbiota in this critical cycle. Here we present pioneering research based on in situ real-time monitoring of CO2 and CH4 diffusive fluxes and concurrent δ13C geochemical tracing in caves, combined with 16S microbiome analysis. Our findings show that cave sediments are promoting continuous CH4 consumption from cave atmosphere, resulting in a significant removal of 65% to 90%. This research reveals the most effective taxa and metabolic pathways in consumption and uptake of greenhouse gases. Methanotrophic bacteria were the most effective group involved in CH4 consumption, namely within the families Methylomonaceae, Methylomirabilaceae and Methylacidiphilaceae. In addition, Crossiella and Nitrosococcaceae wb1-P19 could be one of the main responsible of CO2 uptake, which occurs via the Calvin-Benson-Bassham cycle and reversible hydration of CO2. Thus, syntrophic relationships exist between Crossiella and nitrifying bacteria that capture CO2, consume inorganic N produced by heterotrophic ammonification in the surface of sediments, and induce moonmilk formation. Moonmilk is found as the most evolved phase of the microbial processes in cave sediments that fixes CO2 as calcite and intensifies CH4 oxidation. From an ecological perspective, cave sediments act qualitatively as soils, providing fundamental ecosystem services (e.g. nutrient cycling and carbon sequestration) with direct influence on greenhouse gas emissions.This work was supported by the Spanish Ministry of Science, Innovation through project PID2019-110603RB-I00, MCIN/AEI/FEDER, UE/10.13039/501100011033 and with collaboration of projects RTI2018-099052-B-I00 and PID2020-114978GB-I00. This research has also received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 844535 — MIFLUKE

Microbial Activity in Subterranean Ecosystems: Recent Advances

Of the several critical challenges present in environmental microbiology today, one is the assessment of the contribution of microorganisms in the carbon cycle in the Earth-climate system. Karstic subterranean ecosystems have been overlooked until recently. Covering up to 25% of the land surface and acting as a rapid CH4 sink and alternately as a CO2 source or sink, karstic subterranean ecosystems play a decisive role in the carbon cycle in terms of their contribution to the global balance of greenhouse gases. Recent data indicate that microbiota must play a significant ecological role in the biogeochemical processes that control the composition of the subterranean atmosphere, as well as in the availability of nutrients for the ecosystem. Nevertheless, there are still essential gaps in our knowledge concerning the budgets of greenhouse gases at the ecosystem scale and the possible feedback mechanisms between environmental-microclimatic conditions and the rates and type of activity of microbial communities in subterranean ecosystems. Another challenge is searching for bioactive compounds (antibiotics) used for treating human diseases. At present, there is a global health emergency and a strong need for novel biomolecules. In recent decades, great research efforts have been made to extract antibiotics from marine organisms. More recently, caves have been receiving considerable attention in search of novel antibiotics. Cave methanotrophic and heterotrophic bacteria are producers of bioactive compounds and may be potential sources of metabolites with antibacterial, antifungal or anticancer activities of interest in pharmacological and medical research, as well as enzymes with a further biotechnological use. Here we also show that bacteria isolated from mines, a still unexplored niche for scientists in search of novel compounds, can be a source of novel secondary metabolites.Financial support was obtained through project 0483_PROBIOMA_5_E, co-financed by the European Regional Development Fund within the framework of the Interreg V-A Spain-Portugal program (POCTEP) 2014–2020. This work was also supported by the Spanish Ministry of Economy and Competitiveness through projects CGL2016-75590-P and PID2019-110603RB-I00, AEI/FEDER, UE

Crossiella, a Rare Actinomycetota Genus, Abundant in the Environment

The genus Crossiella contains two species, C. equi, causing nocardioform placentitis in horses, and C. cryophila, an environmental bacterium. Apart from C. equi, which is not discussed here, environmental Crossiella is rarely reported in the literature; thus, it has not been included among “rare actinobacteria”, whose isolation frequency is very low. After C. cryophila, only five reports cover the isolation of Crossiella strains. However, the frequency of published papers on environmental Crossiella has increased significantly in recent years due to the extensive use of next-generation sequencing (NGS) and a huge cascade of data that has improved our understanding of how bacteria occur in the environment. In the last five years, Crossiella has been found in different environments (caves, soils, plant rhizospheres, building stones, etc.). The high abundance of Crossiella in cave moonmilk indicates that this genus may have an active role in moonmilk formation, as evidenced by the precipitation of calcite, witherite, and struvite in different culture media. This review provides an overview of environmental Crossiella, particularly in caves, and discusses its role in biomineralization processes and bioactive compound production.This research was funded by the projects PID2020-114978GB-I00 and PID2019-110603RB-I00. The Malaga City Council financed data from the archaeological basement of the Thyssen Museum of Malaga through a conservation contract for this Roman site

Adaptive response of prokaryotic communities to extreme pollution flooding in a Paleolithic rock art cave (Pindal Cave, northern Spain)

A flood event affecting Pindal Cave, a UNESCO World Heritage site, introduced a substantial amount of external sediments and waste into the cave. This event led to the burial of preexisting sediments, altering the biogeochemical characteristics of the cave ecosystem by introducing heightened levels of organic matter, nitrogen compounds, phosphorus, and heavy metals. The sediments included particulate matter and waste from a cattle farm located within the water catchment area of the cavity, along with diverse microorganisms, reshaping the cave microbial community. This study addresses the ongoing influence of a cattle farm on the cave ecosystem and aims to understand the adaptive responses of the underground microbial community to the sudden influx of waste allochthonous material. Here, we show that the flood event had an immediate and profound effect on the cave microbial community, marked by a significant increase in methanogenic archaea, denitrifying bacteria, and other microorganisms commonly associated with mammalian intestinal tracts. Furthermore, our findings reveal that one year after the flood, microorganisms related to the flood decreased, while the increase in inorganic forms of ammonium and nitrate suggests potential nitrification, aligning with increased abundances of corresponding functional genes involved in nitrogen cycling. The results reveal that the impact of pollution was neither recent nor isolated, and it was decisive in stopping livestock activity near the cave. The influence of the cattle farm has persisted since its establishment over the impluvium area, and this influence endures even a year after the flood. Our study emphasizes the dynamic interplay between natural events, anthropogenic activities, and microbial communities, offering insights into the resilience of cave ecosystems. Understanding microbial adaptation in response to environmental disturbances, as demonstrated in this cave ecosystem, has implications for broader ecological studies and underscores the importance of considering temporal dynamics in conservation efforts.This work was supported by the Spanish Ministry of Science and Innovation through project PID2019-110603RB-I00 and the collaboration of PID2020-114978GB-I00 project, MCIN/AEI/FEDER, UE/10.13039/501100011033. The microbiological analyses of the 2019 flood samples were financed by the “Consejería de Cultura, Política lingüística y Turismo del Principado de Asturias”

Micromorphological Study of Site Formation Processes at El Sidrón Cave (Asturias, Northern Spain): Encrustations over Neanderthal Bones

El Sidrón Cave is an archaeological and anthropological reference site of the Neanderthal world. It shows singular activity related to cannibalisation, and all existing processes are relevant to explain the specific behaviour of the concerned individuals. This paper presents geoarchaeological data, primarily based on mineralogical and petrographic techniques, from an investigation of the nature of the encrustations or hard coatings that affect a large part of the Neanderthal bone remains and their relationship with the depositional and post-depositional processes at the archaeological site. Crusts and patina were found to be numerous and diverse, mainly composed of calcite and siliciclastic grains, with different proportions and textures. The analysis indicated different origins and scenarios from their initial post-mortem accumulation to the final deposit recovered during the archaeological work. The presence of micromorphological features, such as clotted-peloidal micrite, needle-fibre calcite (NFC) aggregates, clay coatings, iron–manganese impregnation, and/or adhered aeolian dust may indicate that a significant proportion of the remains were affected by subaerial conditions in a relatively short period of time in a shelter, cave entrance, or shallower level of the karstic system, prior to their accumulation in the Ossuary Gallery.This work has been supported since 1999 through different research contracts between the Government of the Principality of Asturias, the University of Oviedo, the University of Alicante, the National Museum of Natural Sciences (CSIC, Madrid), and the University of Salamanca

Estudio de adsorbentes para eliminación de nitratos y bromatos en aguas con vista al desarrollo de un sistema continuo de eliminación de oxoaniones

Entre los compuestos que afectan al agua del periurbano bonaerense1 se encuentra el NO3 -. Éste es transformado a NO2 - en el organismo causando metahemoglobinemia, una deficiencia de oxígeno en la sangre. El BrO3 - se genera a partir de Br- por la ozonización del agua para potabilizarla y está clasificado como cancerígeno (IARC).Centro de Investigación y Desarrollo en Ciencias Aplicada

Geoarchaeological study of the Sidrón cave (Piloña, Asturias)

El relleno sedimentario que alberga el registro arqueológico y antropológico de la Galería del Osario (cueva de El Sidrón) presenta una alta complejidad, tanto en los tipos de sedimentos como en su distribución espacial en la cavidad. Los principales factores que rigen esta complejidad son la naturaleza episódica y altamente energética de gran parte de las unidades litoestratigráficas reconocidas y la irregular geometría del propio conducto, que compartimenta significativamente las áreas de deposición. A modo de resumen puede indicarse que en la Galería del Osario quedan representados todos los tipos de materiales detríticos típicos de depósitos alóctonos en ambiente kárstico; desde materiales bien seleccionados de granulometría fina representativos de facies de encharcamiento (arcillas de la unidad O) o de desbordamiento (Unidad IV), a depósitos groseros mal seleccionados correspondientes a coladas de barro y detritos en masa (Unidad II y base de unidad III), pasando por típicas facies fluvio-kársticas o de canal compuestas por materiales arenosos con laminaciones y estructuras de flujo (unidades I y II). Los restos óseos se concentran en la unidad III. El área fuente se sitúa en cotas superiores a la Galería del Osario, es decir, en los niveles intermedio o superior del sistema kárstico, y el depósito o entrada de material óseo a la Galería del Osario se activaría en episodios de alta energía relacionado con eventos de inundación y/o tormenta.The sedimentary infill bearing the archaeological and anthropological record of the Ossuary Gallery (the Sidrón cave) shows high complexity in both sediment types and their spatial distribution in the cavity. The main factors that govern this complexity are the episodic and highly energetic nature of the recorded sedimentary infill units and the irregular geometry of the gallery itself, which significantly compartmentalized areas of deposition. Briefly, all types of typical allochthonous detrital material deposits in karst environments are represented in the Ossuary Gallery; from well-sorted fine-grained sediment facies representative of backswamp (clays of the unit O) or slackwater (Unit IV), to poorly-sorted coarse-grained deposits corresponding to mudflows and debris flows (Unit II and Unit III base), and typical channel facies composed of laminated sands and silts (units I and II). The bone and lithic remains are concentrated in unit III. The source area is above the Ossuary Gallery, at the intermediate or higher karst levels. The input of archeological material to the Ossuary Gallery was triggered in high energy episodes in association to flood events and / or storms.Este trabajo se ha financiado desde 1999 mediante diferentes contratos de investigación realizados entre el Gobierno del Principado de Asturias, la Universidad de Oviedo, la Universidad de Alicante, el Museo Nacional de Ciencias Naturales (CSIC, Madrid) y la Universidad de Salamanca