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Full-Text Articles in Microbiology

Antimicrobial Resistance Of Cultivable Bacteria Isolated From Sorcerer’S Cave In Texas, Jennifer R. Huddleston, David E. Sanderson, Braden J. Smith, Joshua M. Brokaw, Evan M. Babb, Jeffrey T. Wooliscroft Jan 2026

Antimicrobial Resistance Of Cultivable Bacteria Isolated From Sorcerer’S Cave In Texas, Jennifer R. Huddleston, David E. Sanderson, Braden J. Smith, Joshua M. Brokaw, Evan M. Babb, Jeffrey T. Wooliscroft

International Journal of Speleology

Studying caves with minimal human contact offers insights into antimicrobial resistance before human influence. In this study, we isolated 315 bacterial strains from Sorcerer’s Cave in Texas and evaluated their resistance to seven common antimicrobials. Under half (41.4%) of the Gram-positive isolates and 68.4% of the Gram-negative isolates were resistant to three or more antimicrobials. The two most common genera identified were Pseudomonas and Bacillus. Compared to bacteria isolated in previous cave studies, Sorcerer’s Cave bacteria exhibited more extensive antimicrobial resistance. This study underscores the importance of minimally disturbed cave environments in advancing our knowledge of antimicrobial resistance present …


First Report Of A Bat Guano Fire From A Cave In Southeast Asia, Sopark Jantarit, Martin Ellis, Pruet Kalasuwan, Neeranuch Phusunti, Pimonsri Mittraparp-Arthorn, Jiranan Pattano, Arnon Chukamnerd, Turdtun Tong-In, Natthawut Khrueaaunruean Nov 2025

First Report Of A Bat Guano Fire From A Cave In Southeast Asia, Sopark Jantarit, Martin Ellis, Pruet Kalasuwan, Neeranuch Phusunti, Pimonsri Mittraparp-Arthorn, Jiranan Pattano, Arnon Chukamnerd, Turdtun Tong-In, Natthawut Khrueaaunruean

International Journal of Speleology

Fires occurring in cave guano are a rare and unusual phenomenon and the occurrence of such events in Southeast Asia is particularly novel. In this study, we document the first recorded instance of a bat guano fire in a tropical cave at Tham Chao Ram in Sukhothai province, northern Thailand. A bacteriological analysis was made of the guano at the fire site and from a control site within the cave. We give a comprehensive review of global reports on bat guano fires in caves, conduct an initial investigation of the physical factors at the fire site and discuss the potential …


First Insight On The Genesis Of Iron Oxide-Hydroxide Biospeleothems In Rancho Chico Lava Tube, Mexico, Rafael López-Martínez, Elizabeth Solleiro-Rebolledo, Rocio Alcántara-Hernández, Teresa Pi Puig, Sergey Sedov, Daisy Valera Fernández, M. Nayeli Luis-Vargas, Yasmany Lima Vera, Jesús Solé, Ramon Espinasa-Pereña Jun 2025

First Insight On The Genesis Of Iron Oxide-Hydroxide Biospeleothems In Rancho Chico Lava Tube, Mexico, Rafael López-Martínez, Elizabeth Solleiro-Rebolledo, Rocio Alcántara-Hernández, Teresa Pi Puig, Sergey Sedov, Daisy Valera Fernández, M. Nayeli Luis-Vargas, Yasmany Lima Vera, Jesús Solé, Ramon Espinasa-Pereña

International Journal of Speleology

Iron is a common element in lava tube systems, typically observed as thin crusts or inferred from the reddish coloration of secondary mineral deposits. In this study, we describe iron oxide-hydroxide biospeleothems discovered in the Rancho Chico Lava Tube, located within the Xalapa Monogenetic Volcanic Field in Mexico. We adopt an integrative approach combining petrography, soil micromorphology, scanning electron microscopy, mineralogy, and 16S rRNA gene metabarcoding. DNA sequencing reveals the presence of microorganisms such as Acidithiobacillus, Gallionella, and members of the Leptospirillaceae family, which may be involved in the oxidation of Fe²⁺ within the lava tube. The source …


Cyanobacteria And Algae From Chýnov And Koněprusy Caves (Czech Republic), Michaela Wipplingerová, Jan Pokorný, Jan Kaštovský Mar 2025

Cyanobacteria And Algae From Chýnov And Koněprusy Caves (Czech Republic), Michaela Wipplingerová, Jan Pokorný, Jan Kaštovský

International Journal of Speleology

Algae and cyanobacteria have been studied in two so far phycologically unexplored show caves (Chýnov and Koněprusy) in the Czech Republic. Taxa were identified morphologically using cultivation and subsequent light microscopy, while problematic cyanobacterial species were verified by sequencing the genes for 16S rRNA and 16S–23S internal transcribed spacer. A total of 13 cyanobacterial taxa were found, two Bacillariophyceae, three Xanthophyceae, four Chlorophyceae, six Trebouxiophyceae, 11 Streptophyta, and three Euglenida; many of these species were found for the first time in the caves. The darker parts of the caves were dominated by cyanobacteria, and green algae were found predominantly right …


Degradation Of Cyanobacteria And Microalgae Using Ultraviolet Radiation At 222 Nm And Its Application In The Bleaching Of Lampenflora On Cave Rock Surfaces, Keisuke Naito, Shuji Watanabe, Masuo Komukai, Takehiro Kazama, Masayuki Itoh, Masahiro Kawasaki Dec 2024

Degradation Of Cyanobacteria And Microalgae Using Ultraviolet Radiation At 222 Nm And Its Application In The Bleaching Of Lampenflora On Cave Rock Surfaces, Keisuke Naito, Shuji Watanabe, Masuo Komukai, Takehiro Kazama, Masayuki Itoh, Masahiro Kawasaki

International Journal of Speleology

Cyanobacterial and microalgae blooms negatively affect ecological environments. One of the emerging problems of these blooms occurs in calcareous caves, where visible lighting systems in tourist caves induce the formation of photosynthetic biofilms known as lampenflora on rock surfaces. In this study, we evaluated the inactivation effect of ultraviolet (UV) light irradiation at 222 nm (rare gas halide lamp) and 254 nm (mercury lamp) on cyanobacteria and microalgae in a laboratory and on lampenflora in Ryusenshindo Cave in Japan. Based on the laboratory experiments, irradiation at 222-nm was more effective than that at 254-nm for degrading plants. The photosensitivity of …


Time-Transgressive Microbial Diversity In A Tropical Bat Guano Accumulation, Deer Cave, Mulu, Borneo, Joyce Lundberg, Donald A. Mcfarlane Aug 2024

Time-Transgressive Microbial Diversity In A Tropical Bat Guano Accumulation, Deer Cave, Mulu, Borneo, Joyce Lundberg, Donald A. Mcfarlane

International Journal of Speleology

Bat guano accumulations in caves can constitute large deposits of organic material, particularly chitin and its degradation products, that host a diverse microbiome. Previous microbiological studies have not addressed the stratified nature of these deposits in the context of the timeframe of the decomposition process. We present such data (temperature, pH, DNA sampling of eight carbon-dated strata) for a 75 cm-deep tropical guano accumulation that undergoes complete decomposition over a timescale of ~120 years. The aerobic, surface layer of freshly-fallen guano has the greatest diversity of taxa, with Bacteroidota co-dominant with Pseudomonadota, and includes many taxa unique to this …


Algae And Cyanobacteria In The Aphotic Habitats Of Veternica Cave (Medvednica Mt., Croatia) And Selected Caves Of The Dinaric Karst (South-Eastern Europe), Najla Baković, Tanja Pipan, Robert Baković, Roman Ozimec, Josip Rubinić, Renata Matoničkin Kepčija Nov 2022

Algae And Cyanobacteria In The Aphotic Habitats Of Veternica Cave (Medvednica Mt., Croatia) And Selected Caves Of The Dinaric Karst (South-Eastern Europe), Najla Baković, Tanja Pipan, Robert Baković, Roman Ozimec, Josip Rubinić, Renata Matoničkin Kepčija

International Journal of Speleology

Microphototrophs (algae and cyanobacteria) in karst environments have been intensively studied in aquatic epigean habitats. In recent decades knowledge about the communities inhabiting cave entrances and lampenflora has grown substantially, but the data about the communities in aphotic cave zone are scarce. This study aimed to investigate spatio-temporal presence of microphototrophs in the aphotic zone of Veternica Cave (Mt. Medvednica karst) and to present additional preliminary data from 22 caves of the Dinaric karst. The data were collected over ten years, in parallel with research on cave phagotrophic protists. In addition to the remains of microphototrophs, living algae and cyanobacteria …


Monitoring Photosynthetic Activity Using In Vivo Chlorophyll A Fluorescence In Microalgae And Cyanobacteria Biofilms In The Nerja Cave (Malaga, Spain), Yolanda Del Rosal, Juan Muñoz-Fernández, Paula S.M. Celis-Plá, Mariona Hernández-Mariné, Félix Álvarez-Gómez, Salvador Merino, Félix L. Figueroa Dec 2021

Monitoring Photosynthetic Activity Using In Vivo Chlorophyll A Fluorescence In Microalgae And Cyanobacteria Biofilms In The Nerja Cave (Malaga, Spain), Yolanda Del Rosal, Juan Muñoz-Fernández, Paula S.M. Celis-Plá, Mariona Hernández-Mariné, Félix Álvarez-Gómez, Salvador Merino, Félix L. Figueroa

International Journal of Speleology

The characterization of the most common photosynthetic biofilms in the Nerja Cave by the continuous monitoring of the in vivo chlorophyll a (Chl a) fluorescence and the incorporation of the irradiance as a new environmental variable related to previous studies in the cave, have allowed us to improve our knowledge about the photosynthetic pattern of the biofilms of the cave. Effective quantum yield (ΔF/Fm) and relative electron transport rate (rETR) were determined during periods of the light, whereas the maximal quantum yield (Fv /Fm) was determined during dark periods. Increases in …


Microbially-Mediated Carbonate Dissolution And Precipitation; Towards A Protocol For Ex-Situ, Cave-Analogue Cultivation Experiments, Vanessa E. Johnston, Andrea Martín-Pérez, Sara Skok, Janez Mulec Apr 2021

Microbially-Mediated Carbonate Dissolution And Precipitation; Towards A Protocol For Ex-Situ, Cave-Analogue Cultivation Experiments, Vanessa E. Johnston, Andrea Martín-Pérez, Sara Skok, Janez Mulec

International Journal of Speleology

Subterranean calcite dissolution and precipitation are often considered as strictly geochemical processes. The active involvement of microbes in these processes is commonly underestimated in the literature due to general oligotrophic conditions in caves, except in particular cave conditions, such as sulfidic caves and moonmilk deposits, where the presence of microbes likely plays a key role in mineral deposition. Here, we study the possible involvement of microbes from Postojna Cave, Slovenia, in carbonate dissolution (litholysis) and precipitation (lithogenesis). Microbes were sampled from small pools below hydrologically diverse drip sites and incubated on polished limestone tablets at 10 and 20°C for 2 …


Microbiological Study In A Gneissic Cave From Sri Lanka, With Special Focus On Potential Antimicrobial Activities, Ethige Isuru P. Silva, Pathmakumara Jayasingha, Saman Senanayake, Anura Dandeniya, Dona Helani Munasinghe Mar 2021

Microbiological Study In A Gneissic Cave From Sri Lanka, With Special Focus On Potential Antimicrobial Activities, Ethige Isuru P. Silva, Pathmakumara Jayasingha, Saman Senanayake, Anura Dandeniya, Dona Helani Munasinghe

International Journal of Speleology

The emergence of antibiotic resistance is a global health crisis, thus the search for novel antimicrobial compounds has become a continuous necessity. Underexplored and extreme environments, such as cave ecosystems, have been identified as a promising potential source for the discovery of novel microorganisms with novel antimicrobial compounds (AMC). This study presents the first cave microbiological investigation in Sri Lanka, with a special preference for bioprospecting of novel AMC. The cave sediment characterization demonstrated the presence of close to strong acidic conditions (pH 3.1 – 3.3) and thus indicates the possibility of isolating acidophilic microorganisms. Eight cave wall/ceiling fungal strains …


The Impact Of Sample Processing And Media Chemistry On The Culturable Diversity Of Bacteria Isolated From A Cave, Katey E. Bender, Katelyn Glover, Alexander Archey, Hazel A. Barton Oct 2020

The Impact Of Sample Processing And Media Chemistry On The Culturable Diversity Of Bacteria Isolated From A Cave, Katey E. Bender, Katelyn Glover, Alexander Archey, Hazel A. Barton

International Journal of Speleology

Although molecular approaches can identify members of microbial communities in the environment, genomic information does not necessarily correlate with environmental phenotype. Understanding functional roles can be done by cultivating representative species, yet the culturablility of bacteria from caves remains low, at 0.02%, limiting our understanding of microbial community interactions and processes. We have investigated several factors influencing culturability of bacteria from a single sample location in Maxwelton Sink Cave, WV, USA. Extended incubation of inoculated plates showed a significant increase in colony counts from two to four weeks, indicating that extended incubations increase culturability. There were no significant differences in …


Did You Wash Your Caving Suit? Cavers’ Role In The Potential Spread Of Pseudogymnoascus Destructans, The Causative Agent Of White-Nose Disease, Violeta Zhelyazkova, Antonia Hubancheva, Georgi Radoslavov, Nia Toshkova, Sebastien J. Puechmaille Sep 2020

Did You Wash Your Caving Suit? Cavers’ Role In The Potential Spread Of Pseudogymnoascus Destructans, The Causative Agent Of White-Nose Disease, Violeta Zhelyazkova, Antonia Hubancheva, Georgi Radoslavov, Nia Toshkova, Sebastien J. Puechmaille

International Journal of Speleology

White-Nose Disease (WND) has killed millions of hibernating bats in the US and Canada. Its causative agent, the fungus Pseudogymnoascus destructans was introduced to North America, but is native to Europe and Asia, where it is not associated with mass mortality. Although it is nearly impossible to eradicate an emerging wildlife disease, research on P. destructans spread mechanisms can aid in prevention of new introductions and development of better environmental management strategies. It is of particular importance to quantify the potential role of people visiting caves (cavers, tourists, bat researchers, etc.) whom inadvertently move P. destructans spores between sites, and …


Active Growth Of Non-Hydrothermal Subaqueous And Subaerial Barite (Baso4) Speleothems In Lechuguilla Cave (New Mexico, Usa), Max Wisshak, Hazel A. Barton, Katey E. Bender, Harvey R. Duchene Jan 2020

Active Growth Of Non-Hydrothermal Subaqueous And Subaerial Barite (Baso4) Speleothems In Lechuguilla Cave (New Mexico, Usa), Max Wisshak, Hazel A. Barton, Katey E. Bender, Harvey R. Duchene

International Journal of Speleology

Barite (BaSO4) speleothems have been reported from caves around the globe and interpreted to have chiefly formed in phreatic, hypogene, hydrothermal settings. Here we report two contrasting types of barite speleothems (bluish tabular crystals in a shallow pool and actively dripping greenish stalactites), which today form at lower temperatures in the non-hydrothermal and vadose environment of Lechuguilla Cave, New Mexico, USA. Scanning electron microscopy analysis, along with energy- and wavelength-dispersive X-ray spectroscopy (EDS, WDS), as well as X-ray diffraction (XRD), characterize the habit and chemical composition as barite. Fractionation of the minor element calcium is related to growth …


Survey Of Histoplasma Capsulatum In Bat Guano And Status Of Histoplasmosis In Slovenia, Central Europe, Janez Mulec, Saša Simčič, Tadeja Kotar, Romina Kofol, Sanja Stopinšek Jan 2020

Survey Of Histoplasma Capsulatum In Bat Guano And Status Of Histoplasmosis In Slovenia, Central Europe, Janez Mulec, Saša Simčič, Tadeja Kotar, Romina Kofol, Sanja Stopinšek

International Journal of Speleology

There have been increasing reports on the presence of Histoplasma capsulatum in some European countries. The study investigated the presence of Histoplasma in bat guanos, speleologists with records of visiting Histoplasma-endemic regions and patients with histoplasmosis. A commercial ALPHA Histoplasma Antigen enzyme immunoassay was tested as an alternative methodology to detect Histoplasma in environment and compared with polymerase chain reaction (PCR) assays. The presence of Histoplasma antigen in bat guanos was not confirmed by PCR. Among 14 healthy speleologists, two were indicated as having the Histoplasma antigen in urine, but expressed negative PCR-specific results for the Histoplasma antigen. Five …


Screening The Cultivable Cave Microbial Mats For The Production Of Antimicrobial Compounds And Antibiotic Resistance, Jerneja Ambrožič Avguštin, Patricia Petrič, Lejla Pašić Dec 2019

Screening The Cultivable Cave Microbial Mats For The Production Of Antimicrobial Compounds And Antibiotic Resistance, Jerneja Ambrožič Avguštin, Patricia Petrič, Lejla Pašić

International Journal of Speleology

The current work extends the phenotypic characterization of a bacterial culture collection obtained from white, yellow, grey or pink microbial cave wall colonies that are common in the caves of Slovenian Karst. We have determined antibiotic resistance to 22 natural and synthetic antibiotics in 69 isolates from the microbial mats. Thirty-eight isolates (52%) were resistant to 1-5 antibiotics; another 27 isolates (37%) were resistant to 6-10 antibiotics; and 7 isolates (0.1%) were resistant to 11-17 antibiotics. We screened for production of antimicrobial compounds by growing cave isolates on five different media and overlaying individual cultures with ten Gram-positive and Gram …


Are Microclimate Conditions In El Malpais National Monument Caves In New Mexico, Usa Suitable For Pseudogymnoascus Growth?, Terry J. Torres-Cruz, Andrea Porras-Alfaro, Nicole A. Caimi, Ogochukwu Nwabologu, Edward W. Strach, Kaitlyn J.H. Read, Jesse M. Young, Debbie C. Buecher, Diana E. Northup Aug 2019

Are Microclimate Conditions In El Malpais National Monument Caves In New Mexico, Usa Suitable For Pseudogymnoascus Growth?, Terry J. Torres-Cruz, Andrea Porras-Alfaro, Nicole A. Caimi, Ogochukwu Nwabologu, Edward W. Strach, Kaitlyn J.H. Read, Jesse M. Young, Debbie C. Buecher, Diana E. Northup

International Journal of Speleology

White-nose syndrome (WNS) is a bat disease caused by the fungal pathogen Pseudogymnoascus destructans, which thrives in cold and very humid environments where bats frequently hibernate. Conidia of Pseudogymnoascus species are often documented on bats prior to the onset of WNS, but characterization of high-risk areas defined by microclimate cave conditions have been lacking. Investigating the occurrence of this fungal genus and appropriate environmental conditions to support P. destructans in southwestern U.S. caves is key to understanding the sites most likely to be impacted by WNS. Microclimate conditions in ten caves at El Malpais (ELMA) National Monument in New …


Culture-Based Analysis Of ‘Cave Silver’ Biofilms On Rocks In The Former Homestake Mine In South Dakota, Usa, Amanpreet K. Brar, David Bergmann Jun 2019

Culture-Based Analysis Of ‘Cave Silver’ Biofilms On Rocks In The Former Homestake Mine In South Dakota, Usa, Amanpreet K. Brar, David Bergmann

International Journal of Speleology

Tunnels in a warm, humid area of the 1478 m level of the Sanford Underground Research Facility (SURF), located in a former gold mine in South Dakota, USA, host irregular, thin whitish, iridescent biofilms, which appear superficially similar to ‘cave silver’ biofilms described from limestone and lava tube caves, despite the higher rock temperature (32°C) and differing rock surface (phyllite) present at SURF. In this study, we investigated the diversity of cultivable bacteria constituting the cave silver by using several media: CN agar, CN gellan gum and 0.1X R2A agar. The highest colony count (CFU/g of sample) was observed on …


Cyanobacterial And Algal Abundance And Biomass In Cave Biofilms And Relation To Environmental And Biofilm Parameters, Slađana Popović, Nataša Nikolić, Jelena Jovanović, Dragana Predojević, Ivana Trbojević, Ljiljana Manić, Gordana Subakov Simić Feb 2019

Cyanobacterial And Algal Abundance And Biomass In Cave Biofilms And Relation To Environmental And Biofilm Parameters, Slađana Popović, Nataša Nikolić, Jelena Jovanović, Dragana Predojević, Ivana Trbojević, Ljiljana Manić, Gordana Subakov Simić

International Journal of Speleology

Due to life in extreme environments, cyanobacteria and algae from cave biofilms that form at the entrances or deep inside the cave around artificial lights are of increasing interest to many scientists. It is well-known that many phototrophic microorganisms are first to colonize exposed substrata and produce the organic matter on which other biofilm constituents relly. Many studies dealing with phototrophic microorganisms from biofilms focus on the diversity and community composition of cyanobacteria and algae, while quantitative assessments are rarely implemented. Biofilm sampling was conducted in Degurić and Vernjikica Cave located in Western and Eastern Serbia, respectively. Ecological parameters (temperature, …


Bacterial Diversity Associated With Mineral Substrates And Hot Springs From Caves And Tunnels Of The Naica Underground System (Chihuahua, Mexico), Adriana Espino Del Castillo, Hugo Beraldi-Campesi, Patricia Amador-Lemus, Hiram Isaac Beltrán, Sylvie Le Borgne Jun 2018

Bacterial Diversity Associated With Mineral Substrates And Hot Springs From Caves And Tunnels Of The Naica Underground System (Chihuahua, Mexico), Adriana Espino Del Castillo, Hugo Beraldi-Campesi, Patricia Amador-Lemus, Hiram Isaac Beltrán, Sylvie Le Borgne

International Journal of Speleology

The Naica Underground System (NUS) in Northern Mexico comprises a lead, zinc, and silver producing mine and displays the largest gypsum crystals ever found in natural caves. The caves are now closed to the public and mining activities have been suspended for an undefined period since October 2015. Besides its geological, economical, and tourist importance, the bacterial diversity in the NUS has not been fully explored yet. This study surveyed for bacteria present on different mineral substrates (gypsum crystals, iron oxide crusts) and hot spring samples collected before the NUS was inaccessible, using culture-dependent and culture–independent (PCR-DGGE) methods. This study …


Antimicrobial Activities Of Culturable Microorganisms (Actinomycetes And Fungi) Isolated From Chaabe Cave, Algeria, Larbi Belyagoubi, Nabila Belyagoubi-Benhammou, Valme Jurado, Joëlle Dupont, Sandrine Lacoste, Fatima Djebbah, Fatima Z. Ounadjela, Souad Benaissa, Salim Habi, Djamel E. Abdelouahid, Cesareo Saiz-Jimenez Jun 2018

Antimicrobial Activities Of Culturable Microorganisms (Actinomycetes And Fungi) Isolated From Chaabe Cave, Algeria, Larbi Belyagoubi, Nabila Belyagoubi-Benhammou, Valme Jurado, Joëlle Dupont, Sandrine Lacoste, Fatima Djebbah, Fatima Z. Ounadjela, Souad Benaissa, Salim Habi, Djamel E. Abdelouahid, Cesareo Saiz-Jimenez

International Journal of Speleology

The discovery of new antibiotics and other bioactive microbial metabolites is a priority given the frequency of the emerging multi-drug resistant pathogenic microorganisms. Thus, scientists are searching for new antibiotics in microorganisms isolated from extreme habitats such as caves. In the present study, we aimed to perform the first analysis on culturable microorganisms in the Chaabe Cave (Algeria), and to test the antimicrobial activities of the isolates (Streptomyces spp. and Penicillium spp.). The potential for antimicrobial activity of 47 strains of actinomycetes and 23 strains of fungi were tested on Candida albicans, Staphylococcus aureus, Micrococcus luteus, Listeria monocytogenes, …


Sulfur Cave (Romania), An Extreme Environment With Microbial Mats In A Co2-H2S/O2 Gas Chemocline Dominated By Mycobacteria, Serban M. Sarbu, Joost W. Aerts, Jean-François Flot, Rob J.M. Van Spanning, Calin Baciu, Artur Ionescu, Boglárka M. Kis, Reka Incze, Sándor Sikó-Barabási, Zoltan Para, Botond Hegyeli, Nicu-Viorel Atudorei, Casey Barr, Kenneth Nealson, Ferenc L. Forray, Cristian Lascu, Emily J. Fleming, Wilbert Bitter, Radu Popa May 2018

Sulfur Cave (Romania), An Extreme Environment With Microbial Mats In A Co2-H2S/O2 Gas Chemocline Dominated By Mycobacteria, Serban M. Sarbu, Joost W. Aerts, Jean-François Flot, Rob J.M. Van Spanning, Calin Baciu, Artur Ionescu, Boglárka M. Kis, Reka Incze, Sándor Sikó-Barabási, Zoltan Para, Botond Hegyeli, Nicu-Viorel Atudorei, Casey Barr, Kenneth Nealson, Ferenc L. Forray, Cristian Lascu, Emily J. Fleming, Wilbert Bitter, Radu Popa

International Journal of Speleology

Sulfur Cave (Puturosu Mountain, Romania) is an extreme environment, unique for displaying life in a gas chemocline. The lower part of the cave is filled with CO2, CH4, and H2S of mofettic origin, while the upper part contains air that floats above the heavier volcanic gasses. S° and H2SO4 (from sulfur-oxidation) cover the cave wall at and below the CO2-H2S:O2 gas/gas interface. On the cave wall, near the interface the pH is < 1 and unusual microbial biofilms occur on the rock’s surface. We provide context information on the geology, mineralogy, chemistry and biology to better understand this unique environment. We have used X-ray diffraction, optical microscopy, scanning electron microscopy with EDAX capabilities, stable isotope analysis and 16S and 18S rDNA amplicon sequencing. The most common taxa in the microbial biofilms are Mycobacteria, Acidithiobacillus and Ferroplasmaceae. Liquid water in this system originates solely from condensation of water …


Screening Of Antifungal Susceptibility In Cave-Dwelling Aspergilli And Report Of An Amphotericin B-Resistant Aspergillus Flavus, Erika L.S. Taylor, Gabriella F. Ferreira, Gustavo J.C. Freitas, Rodrigo L. Ferreira, Daniel De Assis Santos, Maria A. De Resende-Stoianoff Aug 2017

Screening Of Antifungal Susceptibility In Cave-Dwelling Aspergilli And Report Of An Amphotericin B-Resistant Aspergillus Flavus, Erika L.S. Taylor, Gabriella F. Ferreira, Gustavo J.C. Freitas, Rodrigo L. Ferreira, Daniel De Assis Santos, Maria A. De Resende-Stoianoff

International Journal of Speleology

Caves are stable environments that favour the development of several microorganisms. The aspergilli represent a large number of species isolated from caves including strains capable of causing serious invasive opportunistic infections in humans. Considering that caves may harbour resistant strains to many antibiotics, investigation on the response of opportunistic aspergilli, isolated from pristine and tourist caves to antifungal agents and the mechanisms involved in resistance might be clinically relevant. A total of 32 strains of the species Aspergillus candidus, A. flavus, A. fumigatus, A. niger, A. tamarii, and A. terreus were isolated from caves in …


Diversity And Biocide Susceptibility Of Fungal Assemblages Dwelling In The Art Gallery Of Magura Cave, Bulgaria, Milena M. Mitova, Mihail Iliev, Alena Nováková, Anna A. Gorbushina, Veneta I. Groudeva, Pedro M. Martin-Sanchez Feb 2017

Diversity And Biocide Susceptibility Of Fungal Assemblages Dwelling In The Art Gallery Of Magura Cave, Bulgaria, Milena M. Mitova, Mihail Iliev, Alena Nováková, Anna A. Gorbushina, Veneta I. Groudeva, Pedro M. Martin-Sanchez

International Journal of Speleology

Magura Cave, north-western Bulgaria, possesses valuable rock-art paintings made with bat guano and dated from the period between the Eneolithic and Bronze Ages. Since 2008, the Art Gallery is closed to the general public in order to protect the paintings from vandalism, microclimatic changes caused by visitors and artificial illumination, and the consequent growth of fungi and phototrophs. Nevertheless, some tourist visits are allowed under the supervision of cave managers. This study provides the first scientific report on cultivable fungal assemblages dwelling different substrata in the Art Gallery. A total of 78 strains, belonging to 37 OTUs (Ascomycota 81%, Zygomycota …


Characterization Of Antimicrobial Activity Of Culturable Bacteria Isolated From Krubera-Voronja Cave, Aiste Klusaite, Vida Vickackaite, Birute Vaitkeviciene, Rasa Karnickaite, Dominykas Bukelskis, Ieva Kieraite-Aleksandrova, Nomeda Kuisiene Oct 2016

Characterization Of Antimicrobial Activity Of Culturable Bacteria Isolated From Krubera-Voronja Cave, Aiste Klusaite, Vida Vickackaite, Birute Vaitkeviciene, Rasa Karnickaite, Dominykas Bukelskis, Ieva Kieraite-Aleksandrova, Nomeda Kuisiene

International Journal of Speleology

In the present study we aimed to perform the first analysis of antimicrobial activity of bacteria isolated from Krubera-Voronja Cave, with the main focus on their activity against Grampositive bacteria, including Gram-positive pathogens. Using five different media, in total 874 heterotrophic cultures were isolated from water and sediment samples collected in Krubera-Voronja Cave at a depth from 220 m to 1640 m. 14.0% of all isolates demonstrated antibacterial activity against Gram-positive and Gram-negative test microorganisms. Our results show that this percentage was not uniform; it increased with the sampling depth and was the highest in the lower part of the …


Atp Luminescence Assay As A Bioburden Estimator Of Biomass Accumulation In Caves, Janez Mulec, Andreea Oarga-Mulec Aug 2016

Atp Luminescence Assay As A Bioburden Estimator Of Biomass Accumulation In Caves, Janez Mulec, Andreea Oarga-Mulec

International Journal of Speleology

A commercially available adenosine triphosphate (ATP) detection system (Hygiena, USA), supported by cultivable microbial indicators, was used to estimate bioburden in different habitats in and outside show caves: air, water and solid surfaces. A strong positive correlation between ATP concentration expressed as Relative Light Units (RLU) and Colony-Forming-Units (CFU) was observed for swab samples from cave surfaces. In terms of ATP units, surfaces in a single cave system (Postojna Cave) varied considerably (240-1,258,800 RLU/ 20 cm2) and commonly exceeded the bioburden level of analogues on the surface (0-114,390 RLU/ 20 cm2). Cave sub-habitats were colonized by …


Diversity Of Cultured Bacteria From The Perennial Ice Block Of Scarisoara Ice Cave, Romania, Corina Iţcuş, Mădălina-Denisa Pascu, Traian Brad, Aurel Perşoiu, Cristina Purcarea Jan 2016

Diversity Of Cultured Bacteria From The Perennial Ice Block Of Scarisoara Ice Cave, Romania, Corina Iţcuş, Mădălina-Denisa Pascu, Traian Brad, Aurel Perşoiu, Cristina Purcarea

International Journal of Speleology

Cave ice ecosystems represent a poorly investigated glacial environment. Diversity of cave ice bacteria and their distribution in perennial ice deposits of this underground glacial habitat could constitute a proxy for microbial response to climatic and environmental changes. Scarisoara Ice Cave (Romania) hosts one of the oldest and largest cave ice blocks worldwide. Here we report on cultured microbial diversity of recent, 400, and 900 years-old perennial ice from this cave, representing the first characterization of a chronological distribution of cave-ice bacteria. Total cell density measured by SYBR Green I epifluorescence microscopy varied in the 2.4 x 104 – …


Fungi On White-Nose Infected Bats (Myotis Spp.) In Eastern Canada Show No Decline In Diversity Associated With Pseudogymnoascus Destructans (Ascomycota: Pseudeurotiaceae), Karen J. Vanderwolf, David Malloch, Donald F. Mcalpine Dec 2015

Fungi On White-Nose Infected Bats (Myotis Spp.) In Eastern Canada Show No Decline In Diversity Associated With Pseudogymnoascus Destructans (Ascomycota: Pseudeurotiaceae), Karen J. Vanderwolf, David Malloch, Donald F. Mcalpine

International Journal of Speleology

The introduction of the fungal pathogen Pseudogymnoascus destructans (Pd) to North America has stimulated research on the poorly known mycology of caves. It is possible that the introduction of Pd reduces the diversity of fungi associated with bats hibernating in caves. To test this hypothesis we examined the fungal assemblages associated with hibernating bats (Myotis spp.) pre- and post- white-nose syndrome (WNS) infection in eastern Canada using culture-dependent methods. We found the mean number of fungal taxa isolated from bats/hibernaculum was not significantly different between pre-infection (29.6 ± 6.1SD) and post-infection with WNS (32.4 ± 4.3). Although …


Cave Cyanobacteria Showing Antibacterial Activity, Vasiliki Lamprinou, Kyriaki Tryfinopoulou, Emmanuel N. Velonakis, Alkiviadis Vatopoulos, Smaragdi Antonopoulou, Elizabeth Fragopoulou, Adriani Pantazidou, Athena Economou-Amilli May 2015

Cave Cyanobacteria Showing Antibacterial Activity, Vasiliki Lamprinou, Kyriaki Tryfinopoulou, Emmanuel N. Velonakis, Alkiviadis Vatopoulos, Smaragdi Antonopoulou, Elizabeth Fragopoulou, Adriani Pantazidou, Athena Economou-Amilli

International Journal of Speleology

Cave Cyanobacteria - thriving in an ‘extreme’ environment with interesting species biodiversity - are supposed to be a potential source of bioactive compounds. Lipid extracts from pure cultures of two recently established Cyanobacteria from Greek caves, Toxopsis calypsus and Phormidium melanochroun, were used for antibacterial screening against human pathogenic bacteria (reference and clinical isolates). Antimicrobial Susceptibility testing for both taxa was carried out using the disc-diffusion (Kirby Bauer) method, while preliminary data applying the standard broth microdilution method for the determination of the Minimal Inhibitory Concentration (MIC) are given only for T. calypsus. Antibacterial activity was demonstrated against the …


Characterization And Fluorescence Of Yellow Biofilms In Karst Caves, Southwest Slovenia, Janez Mulec, Andreea Oarga-Mulec, Rok Tomazin, Tadeja Matos May 2015

Characterization And Fluorescence Of Yellow Biofilms In Karst Caves, Southwest Slovenia, Janez Mulec, Andreea Oarga-Mulec, Rok Tomazin, Tadeja Matos

International Journal of Speleology

Biofilms of different colours that colonize surfaces within karst caves represent a source of nutrients. They occur commonly and abundantly at sites with sediments, and close to seepages or underground rivers. Golden-yellow subaerial biofilms are particularly well observed because of their contrast with their surroundings, the characteristics of the pigment and recently, even more, due to the characteristics of light-emitting diode (LED) illumination. Yellow microbial biofilms were sampled from three caves in southwestern Slovenia, Dimnice, Križna jama and Sveta jama. The highest concentration of cultivable microbes (2.33×108 CFU/g) and the biggest number of identified bacteria (66.0%) were retrieved from …


Cyanobacteria, Algae And Microfungi Present In Biofilm From Božana Cave (Serbia), Slađana Popović, Gordana Subakov Simić, Miloš Stupar, Nikola Unković, Dragana Predojević, Jelena Jovanović, Milica Ljaljević Grbić Feb 2015

Cyanobacteria, Algae And Microfungi Present In Biofilm From Božana Cave (Serbia), Slađana Popović, Gordana Subakov Simić, Miloš Stupar, Nikola Unković, Dragana Predojević, Jelena Jovanović, Milica Ljaljević Grbić

International Journal of Speleology

Phototrophic microorganisms (cyanobacteria and algae) and microfungi, were identified from biofilm on the walls of the entrance of BožanaCavein west Serbia. Temperature, relative humidity and light intensity were measured, and chlorophyll a content determined. Light intensity differed from the entrance inwards. However, Chl a content was not proportional to light intensity, instead it was positively correlated to biofilm weight. Biofilm samples from two sites were also observed using a scanning electron microscope. Coccoid forms of cyanobacteria were abundant at the sampling site with the lowest light intensity, while members of the order Nostocales were predominant at the sampling site with …