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Speleology in Kazakhstan

Shakalov on 04 Jul, 2018
Hello everyone!   I pleased to invite you to the official site of Central Asian Karstic-Speleological commission ("Kaspeko")   There, we regularly publish reports about our expeditions, articles and reports on speleotopics, lecture course for instructors, photos etc. ...

Speleology in Kazakhstan

Shakalov on 04 Jul, 2018
Hello everyone!   I pleased to invite you to the official site of Central Asian Karstic-Speleological commission ("Kaspeko")   There, we regularly publish reports about our expeditions, articles and reports on speleotopics, lecture course for instructors, photos etc. ...

Speleology in Kazakhstan

Shakalov on 11 Jul, 2012
Hello everyone!   I pleased to invite you to the official site of Central Asian Karstic-Speleological commission ("Kaspeko")   There, we regularly publish reports about our expeditions, articles and reports on speleotopics, lecture course for instructors, photos etc. ...

New publications on hypogene speleogenesis

Klimchouk on 26 Mar, 2012
Dear Colleagues, This is to draw your attention to several recent publications added to KarstBase, relevant to hypogenic karst/speleogenesis: Corrosion of limestone tablets in sulfidic ground-water: measurements and speleogenetic implications Galdenzi,

The deepest terrestrial animal

Klimchouk on 23 Feb, 2012
A recent publication of Spanish researchers describes the biology of Krubera Cave, including the deepest terrestrial animal ever found: Jordana, Rafael; Baquero, Enrique; Reboleira, Sofía and Sendra, Alberto. ...

Caves - landscapes without light

akop on 05 Feb, 2012
Exhibition dedicated to caves is taking place in the Vienna Natural History Museum   The exhibition at the Natural History Museum presents the surprising variety of caves and cave formations such as stalactites and various crystals. ...

Did you know?

That ammeter is a meter used to measure the flow of water in a stream channel. synonym: current meter [16].?

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Your search for microbial communities (Keyword) returned 30 results for the whole karstbase:
Showing 16 to 30 of 30
Balancing the conservation needs of sulphidic caves and karst with tourism, economic development, and scientific study, 2008, Porter, Megan L And Annette Summers Engel.
Over the last fifteen years, sulphidic karst has received increasing recognition as unique systems where new discoveries of both biological and geological features have captured the imagination of the public media and the academic community. The unique resources found within both active and relict sulphidic karst systems are globally important to karst conservation issues. In this paper we describe some of the unique geological and biological features of sulphidic caves and karst and present strategies for the conservation and protection of this exceptional habitat.

Geomicrobiology of biovermiculations from the Frasassi Cave System, Italy, 2008, D. S. Jones, E. H. Lyon, And J. L. Macalady

Sulfidic cave walls host abundant, rapidly-growing microbial communities that display a variety of morphologies previously described for vermiculations. Here we present molecular, microscopic, isotopic, and geochemical data describing the geomicrobiology of these biovermiculations from the Frasassi cave system, Italy. The biovermiculations are composed of densely packed prokaryotic and fungal cells in a mineral-organic matrix containing 5 to 25% organic carbon. The carbon and nitrogen isotope compositions of the biovermiculations (d13C 5 235 to 243%, and d15N 5 4 to 227%, respectively) indicate that within sulfidic zones, the organic matter originates from chemolithotrophic bacterial primary productivity. Based on 16S rRNA gene cloning (n567), the biovermiculation community is extremely diverse, including 48 representative phylotypes (.98% identity) from at least 15 major bacterial lineages. Important lineages include the Betaproteobacteria (19.5% of clones), Gammaproteobacteria (18%), Acidobacteria (10.5%), Nitrospirae (7.5%), and Planctomyces (7.5%). The most abundant phylotype, comprising over 10% of the 16S rRNA gene sequences, groups in an unnamed clade within the Gammaproteobacteria. Based on phylogenetic analysis, we have identified potential sulfur- and nitrite-oxidizing bacteria, as well as both auto- and heterotrophic members of the biovermiculation community. Additionally, many of the clones are representatives of deeply branching bacterial lineages with no cultivated representatives. The geochemistry and microbial composition of the biovermiculations suggest that they play a role in acid production and carbonate dissolution, thereby contributing to cave formation.


Productivity-Diversity Relationships from Chemolithoautotrophically Based Sulfidic Karst Systems, 2009, Porter M. L. , Summers Engel A. , Kane T. C. And Kinkle B. K.
Although ecosystems thriving in the absence of photosynthetic processes are no longer considered unique phenomena, we have yet to understand how these ecosystems are energetically sustained via chemosynthesis. Ecosystem energetics were measured in microbial mats from active sulfidic caves (Movile Cave, Romania; Frasassi Caves, Italy; Lower Kane Cave, Wyoming, USA; and Cesspool Cave, Virginia, USA) using radiotracer techniques. We also estimated bacterial diversity using 16S rRNA sequences to relate the productivity measurements to the composition of the microbial communities. All of the microbial communities investigated were dominated by chemolithoautotrophic productivity, with the highest rates from Movile Cave at 281 g C/m2/yr. Heterotrophic productivities were at least one order of magnitude less than autotrophy from all of the caves. We generated 414 new 16S rRNA gene sequences that represented 173 operational taxonomic units (OTUs) with 99% sequence similarity. Although 13% of these OTUs were found in more than one cave, the compositions of each community were significantly different from each other (P?0.001). Autotrophic productivity was positively correlated with overall species richness and with the number of bacterial OTUs affiliated with the Epsilonproteobacteria, a group known for sulfur cycling and chemolithoautotrophy. Higher rates of autotrophy were also strongly positively correlated to available metabolic energy sources, and specifically to dissolved sulfide concentrations. The relationship of autotrophic productivity and heterotrophic cycling rates to bacterial species richness can significantly impact the diversity of higher trophic levels in chemolithoautotrophically-based cave ecosystems, with the systems possessing the highest productivity supporting abundant and diverse macro-invertebrate communities.

Microbial Communities and Associated Mineral Fabrics in Altamira Cave, Spain., 2009, Cuezva S. , Sanchezmoral S. , Saizjimenez C. And Caaveras J. C.
Evidences of microbial colonizations were observed in Altamira Cave, Spain. These consisted of distinct small coloured colonies, both on walls and ceiling, mainly located in the area near the cave entrance, which progressed until reaching the Polychromes Hall. The colonizations were characterized by a high morphological and microstructural variability and related to biomineralization processes. Two main types of CaCO3 deposits were related to the colonies: rosette- or nest-like aggregates of rhombohedral calcite crystals, and spheroid to hemispheroid CaCO3 elements. Colonies distribution seems to be controlled by microenvironmental conditions inside the cavity. The areas of the cave showing higher temperature, relative humidity, and CO2 concentration fluctuations presented a minor biomineralization capability.

MICROORGANISMS AS SPELEOGENETIC AGENTS: GEOCHEMICAL DIVERSITY BUT GEOMICROBIAL UNITY, 2009, Boston P. , Spilde M. , Northup D. , Curry M. , Melim L. , Rosaleslagarde L.

Caves provide habitats for a variety of native microorganisms. Many may be simply living in the subsurface, utilizing various sources of detrital organic matter without exerting much impact on their surroundings. However, some speleologically signi?cant microbial communities appear to interact extensively with their rocky environments. These organisms can exert in?uence on the pace, extent, or nature of cave formation, contribute to precise forms that secondary cave decorations may take, potentially act as major agents of subsurface weathering, and sometimes produce a unique type of cave soil, speleosol. Sulfates and sul?des, iron and manganese, carbonates, copper minerals, or silica, may dominate the geochemistry and lithology of a site, but although the details of the chemistry and microbial diversity may differ, a suite of similar ecological themes with speleological consequences can be seen at work in each. These unifying geomicrobiological themes may be useful in assessing the potential biological interactions to be expected in new types of cave environments and may provide analytical tools in the future to help unravel the geochemistry, hydrology, and geology of such systems both on Earth and other Solar System bodies.


Productivity-Diversity Relationships from Chemolithoautotrophically Based Sulfidic Karst Systems, 2009, Porter M. L. , Summers Engel A. , Kane T. C. , Kinkle B. K.

Although ecosystems thriving in the absence of photosynthetic processes are no longer considered unique phenomena, we have yet to understand how these ecosystems are energetically sustained via chemosynthesis. Ecosystem energetics were measured in microbial mats from active sulfidic caves (Movile Cave, Romania; Frasassi Caves, Italy; Lower Kane Cave, Wyoming, USA; and Cesspool Cave, Virginia, USA) using radiotracer techniques. We also estimated bacterial diversity using 16S rRNA sequences to relate the productivity measurements to the composition of the microbial communities. All of the microbial communities investigated were dominated by chemolithoautotrophic productivity, with the highest rates from Movile Cave at 281 g C/m2/yr. Heterotrophic productivities were at least one order of magnitude less than autotrophy from all of the caves. We generated 414 new 16S rRNA gene sequences that represented 173 operational taxonomic units (OTUs) with 99% sequence similarity. Although 13% of these OTUs were found in more than one cave, the compositions of each community were significantly different from each other (P≤0.001). Autotrophic productivity was positively correlated with overall species richness and with the number of bacterial OTUs affiliated with the Epsilonproteobacteria, a group known for sulfur cycling and chemolithoautotrophy. Higher rates of autotrophy were also strongly positively correlated to available metabolic energy sources, and specifically to dissolved sulfide concentrations. The relationship of autotrophic productivity and heterotrophic cycling rates to bacterial species richness can significantly impact the diversity of higher trophic levels in chemolithoautotrophically-based cave ecosystems, with the systems possessing the highest productivity supporting abundant and diverse macro-invertebrate communities.


Microbial Communities and Associated Mineral Fabrics in Altamira Cave, Spain., 2009, Cuezva S. , Sanchezmoral S. , Saizjimenez C. , Caaveras J. C.

Evidences of microbial colonizations were observed in Altamira Cave, Spain. These consisted of distinct small coloured colonies, both on walls and ceiling, mainly located in the area near the cave entrance, which progressed until reaching the Polychromes Hall. The colonizations were characterized by a high morphological and microstructural variability and related to biomineralization processes. Two main types of CaCO3 deposits were related to the colonies: rosette- or nest-like aggregates of rhombohedral calcite crystals, and spheroid to hemispheroid CaCO3 elements. Colonies distribution seems to be controlled by microenvironmental conditions inside the cavity. The areas of the cave showing higher temperature, relative humidity, and CO2 concentration fluctuations presented a minor biomineralization capability.


Aqueous Geochemical Evidence of Volcanogenic Karstification: Sistema Zacaton, Mexico, 2011, Gary M. O. , Doctor D. H. , Sharp J. M.

The Sistema Zacatón karst area in northeastern Mexico (Tamaulipas state) is limited to a relatively focused area (20 km2) in a carbonate setting not prone to extensive karstification. The unique features found here are characteristic of hydrothermal karstification processes, represent some of the largest phreatic voids in the world, and are hypothesized to have formed from interaction of a local Pleistocene magmatic event with the regional groundwater system. Aqueous geochemical data collected from five cenotes of Sistema Zacatón between 2000 and 2009 include temperature (spatial, temporal, and depth profiles), geochemical depth profiles, major and trace ion geochemistry, stable and radiogenic isotopes, and dissolved gases. Interpretation of these data indicates four major discoveries: 1) rock-water interaction occurs between groundwater, the limestone matrix, and local volcanic rocks; 2) varying degrees of hydrogeological connection exist among cenotes in the system as observed from geochemical signatures; 3) microbially-mediated geochemical reactions control sulfur and carbon cycling and influence redox geochemistry; and 4) dissolved gases are indicative of a deep volcanic source. Dissolved 87Sr/86Sr isotope ratios (mean 0.70719) are lower than those of the surrounding Cretaceous limestone (0.70730-0.70745), providing evidence of groundwater interaction with volcanic rock, which has a 87Sr/86Sr isotope ratio of 0.7050. Discrete hydraulic barriers between cenotes formed in response to sinkhole formation, hydrothermal travertine precipitation, and shifts in the local water table, creating relatively isolated water bodies. The isolation of the cenotes is reflected in distinct water chemistries among them. This is observed most clearly in the cenote Verde where a water level 4-5 meters lower than the adjacent cenotes is maintained, seasonal water temperature variations occur, thermoclines and chemoclines exist, and the water is oxic at all depths. The surrounding cenotes of El Zacatón, Caracol, and La Pilita show constant water temperatures both in depth profile and in time, have similar water levels, and are almost entirely anoxic. A sulfur (H2S) isotope value of δ34S = -1.8 ‰ (CDT) in deep water of cenote Caracol, contrasted with two lower sulfur isotopic values of sulfide in the water near the surface of the cenote (δ34S = -7 ‰ and -8 ‰ CDT). These δ34S values are characteristic of complex biological sulfur cycling where sulfur oxidation in the photic zone results in oxidation of H2S to colloidal sulfur near the surface in diurnal cycles. This is hypothesized to result from changes in microbial community structure with depth as phototropic, sulfur-oxidizing bacteria become less abundant below 20 m. Unique microbial communities exist in the anoxic, hydrothermal cenotes that strongly mediate sulfur cycling and likely influence mineralization along the walls of these cenotes. Dissolved CO2 gas concentrations ranged from 61-173 mg/L and total dissolved inorganic carbon (DIC) δ13C values measured at cenote surfaces ranged from -10.9 ‰ to -11.8 ‰ (PDB), reflecting mixed sources of carbon from carbonate rock dissolution, biogenic CO2 and possibly dissolved CO2 from volcanic sources. Surface measurements of dissolved helium gas concentrations range from 50 nmol/kg to 213 nmol/kg. These elevated helium concentrations likely indicate existence of a subsurface volcanic source; however, helium isotope data are needed to test this hypothesis. The results of these data reflect a speleogenetic history that is inherently linked to volcanic activity, and support the hypothesis that the extreme karst development of Sistema Zacatón would likely not have progressed without groundwater interaction with the local igneous rocks 


Bacterial community survey of sediments at Naracoorte Caves, Australia, 2012, Adetutu E. M. , Thorpe K. , Shahsavari E. , Bourne S. , Cao X. , Fard R. M. N, Kirby G. , Ball A. S.

Bacterial diversity in sediments at UNESCO World Heritage listed Naracoorte Caves was surveyed as part of an investigation carried out in a larger study on assessing microbial communities in caves. Cave selection was based on tourist accessibility; Stick Tomato and Alexandra Cave (> 15000 annual visits) and Strawhaven Cave was used as control (no tourist access). Microbial analysis showed that Bacillus was the most commonly detected microbial genus by culture dependent and independent survey of tourist accessible and inaccessible areas of show (tourist accessible) and control caves. Other detected sediment bacterial groups were assigned to the Firmicutes, Actinobacteria and Proteobacteria. The survey also showed differences in bacterial diversity in caves with human access compared to the control cave with the control cave having unique microbial sequences (Acinetobacter, Agromyces, Micrococcus and Streptomyces). The show caves had higher bacterial counts, different 16S rDNA based DGGE cluster patterns and principal component groupings compared to Strawhaven. Different factors such as human access, cave use and configurations could have been responsible for the differences observed in the bacterial community cluster patterns (tourist accessible and inaccessible areas) of these caves. Cave sediments can therefore act as reservoirs of microorganisms. This might have some implications on cave conservation activities especially if these sediments harbor rock art degrading microorganisms in caves with rock art.


Microbiological Activities in Moonmilk Monitored Using Isothermal Microcalorimetry (Cave of Vers Chez Le Brandt, Neuchatel, Switzerland), 2012, Braissant O. , Binderschedler S. , Daniels A. U. , Verrecchia E. P. , Cailleau G.

 

Studies of the influence of microbial communities on calcium carbonate deposits mostly rely on classical or molecular microbiology, isotopic analyses, and microscopy. Using these techniques, it is difficult to infer microbial activities in such deposits. In this context, we used isothermal microcalorimetry, a sensitive and nondestructive tool, to measure microbial activities associated with moonmilk ex-situ. Upon the addition of diluted LB medium and other carbon sources to fresh moonmilk samples, we estimated the number of colony forming units per gram of moonmilk to be 4.8 3 105 6 0.2 3 105. This number was close to the classical plate counts, but one cannot assume that all active cells producing metabolic heat were culturable. Using a similar approach, we estimated the overall growth rate and generation time of the microbial community associated with the moonmilk upon addition of various carbon sources. The range of apparent growth rates of the chemoheterotrophic microbial community observed was between 0.025 and 0.067 h21 and generation times were between 10 and 27 hours. The highest growth rates were observed for citrate and diluted LB medium, while the highest carbon-source consumption rates were observed for low molecular weight organic acids (oxalate and acetate) and glycerol. Considering the rapid degradation of organic acids, glucose, and other carbon sources observed in the moonmilk, it is obvious that upon addition of nutrients during snow melting or rainfall these communities can have high overall activities comparable to those observed in some soils. Such communities can influence the physico-chemical conditions and participate directly or indirectly to the formation of moonmilk.


Insights into Cave Architecture and the Role of Bacterial Biofilm, 2013,

Caves offer a stable and protected environment from harsh and changing outside conditions. They lend living proof of the presence of minute life forms that delve deep within the earth’s crust where the possibility of life seems impossible. Devoid of all light sources and lacking the most common source of energy supplied through photosynthesis, the mysterious microbial kingdom in caves are consequently dependent upon alternative sources of energy derived from the surrounding atmosphere, minerals and rocks. There are a number of features that can be observed within a cave that may serve as evidence of microbial activity, for example, formation of biofilms comprised of multiple layers of microbial communities held together by protective gel-like polymers which form complex structures. Different bacterial biofilms can develop on the walls of the cave which can be visually distinguished by their colorations. Moreover, the pH generated by the metabolism of bacterial biofilm on the cave environment can lead to precipitation or dissolution of minerals in caves. Caves also offer an excellent scenario for studying biomineralization processes. The findings on the association of bacteria with secondary minerals as mentioned in this review will help to expand the existing knowledge in geomicrobiology and specifically on the influence of microorganisms in the formation of cave deposits. This paper reviews the current state of knowledge of biospeleology of caves and the associated bacterial biofilms. Recommendations for future research are mentioned to encourage a drift from qualitative studies to more experimental studies.


Microbial communities in a coastal cave: Cova des Pas de Vallgornera (Mallorca, Western Mediterranean), 2014, Busquets A. , Fornós J. J. , Zafra F. , Lalucat J. , Merino A.

As a part of an ongoing project on the role of microbes in the biogeochemistry of Majorcan caves, the species diversity of microbial communities present in cave pools of anchialine waters in the Cova des Pas de Vallgornera (Mallorca, western Mediterranean) is investigated by a culture-dependent method. Two-hundred and forty-eight strains isolated from this characteristic cave environment of the littoral karst are identified by whole-cell-MALDI-TOF mass spectrometry and phylogeneticaly by 16S rRNA gene sequences. Total cell counts and species diversity of the bacterial communities decreas with the distance to the entrance of the cave and to the sea. Strains are mainly identified as members of the Gammaproteobacteria and Actinobacteria. Around 20% of the isolates are able to precipitate carbonates. Calcite is the predominant phase, growing in all the precipitates, although struvite is also found in one Pseudomonas and in one Aspergillus cultures. Differences in crystal characteristics of external shape (habit) and growth are observed according to the bacterial species promoting the precipitates. Bacteria associated with multicolored ferromanganese deposits, present in several parts of the cave, are also studied and are identified as Pseudomonas benzenivorans and Nocardioides luteus. The preponderance of Pseudomonas species and the possible contribution of bacteria in calcite deposition are discussed.


Molecular analyses of microbial abundance and diversity in the water column of anchialine caves in Mallorca, Spain., 2014, Menning D. M. , Boop L. M. , Graham E. D. , Garey J. R.

Water column samples from the island of Mallorca, Spain were collected from one site in Cova des Pas de Vallgornera (Vallgornera) and three sites (Llac Martel, Llac Negre, and Llac de les Delícies) in Coves del Drac (Drac). Vallgornera is located on the southern coast of Mallorca approximately 57 km southwest of Coves del Drac. Drac is Europe's most visited tourist cave, whereas Vallgornera is closed to the public. Water samples were analyzed for water chemistry using spectrophotometric methods, by quantitative PCR for estimated total abundance of microbial communities, and by length heterogeneity PCR for species richness and relative species abundance of Archaea, Bacteria, and microbial eukaryotes. Estimated total abundance was multiplied by relative species abundance to determine the absolute species abundance. All sites were compared to determine spatial distributions of the microbial communities and to determine water column physical and chemical gradients. Water quality and community structure data indicate that both Drac Delícies and Drac Negre have distinct biogeochemical gradients. These sites have communities that are similar to Vallgornera but distinct from Drac Martel, only a few hundred meters away. Drac Martel is accessible to the general public and had the most dissimilar microbial community of all the sites. Similarities among communities at sites in Drac and Vallgornera suggest that these two spatially separated systems are operating under similar ecological constraints.


Bacterial migration through low-permeability fault zones in compartmentalised aquifer systems: a case study in Southern Italy., 2014, Bucci Antonio, Petrella Emma, Naclerio Gino, Gambatese Sabrina, Celico Fulvio

The aim of this study was to experimentally verify the significance of microbial transport through low-permeability fault zones in a compartmentalised carbonate aquifer system in Southern Italy.

The temporal variability of microbial communities in two springs fed by the same aquifer system, but discharging up- and down-gradient of two low-permeability fault zones, was analysed using a 16S rDNA polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE)-based approach. At both springs, a remarkable temporal variation in PCR-DGGE profiles was detected throughout the observation period. When comparing the PCR-DGGE profiles of the two springs, a synchronous evolution over time was observed. Moreover, the per cent of PCR-DGGE bands common to both springs progressively increased from early (23%) to late recharge (70%), only to decrease once more in late recession (33%). Considering the results of the hydrogeological and isotopic investigations and EC measurements, the results of biomolecular analyses demonstrate that, at the study site, compartments straddling the analysed fault zones have microbial interconnections, despite the existence of low-permeability fault cores.


Speleothem and biofilm formation in a granite/dolerite cave, Northern Sweden, 2014, Sallstedt Therese, Ivarsson Magnus, Lundberg Johannes, Sjöberg Rabbe, Vidal Romaní Juan Ramón.

Tjuv-Antes grotta (Tjuv-Ante's Cave) located in northern Sweden is a round-abraded sea cave ('tunnel cave'), about 30 m in length, formed by rock-water abrasion in a dolerite dyke in granite gneiss. Abundant speleothems are restricted to the inner, mafic parts of the cave and absent on granite parts. The speleothems are of two types: cylindrical (coralloid, popcorn-like), and flowstone (thin crusts). Coralloids correspond to terrestrial stromatolite speleothems in which layers of light calcite alternate with dark, silica-rich laminae. The dark laminae are also enriched in carbon and contain incorporated remains of microorganisms. Two types of microbial communities can be distinguished associated with the speleothems: an Actinobacteria-like biofilm and a fungal community. Actinobacteria seem to play an important role in the formation of speleothem while the fungal community acts as both a constructive and a destructive agent. A modern biofilm dominated by Actinobacteria is present in the speleothem-free parts of the dolerite and located in cave ceiling cracks. These biofilms may represent sites of early speleothem formation. Because of its unusual position in between two types of host rock, Tjuv-Ante's Cave represents a unique environment in which to study differences in microbe-rock interactions and speleothem genesis between the granite and dolerite host rock. Our study shows that the mafic rock is superior to the granite in hosting a microbial community and to support formation of speleothems.


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