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Samanta B, Sharma S, Budhwar R. Metagenome Analysis of Speleothem Microbiome from Subterranean Cave Reveals Insight into Community Structure, Metabolic Potential, and BGCs Diversity. Curr Microbiol 2023; 80:317. [PMID: 37561193 DOI: 10.1007/s00284-023-03431-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Accepted: 07/26/2023] [Indexed: 08/11/2023]
Abstract
The Borra caves, the second largest subterranean karst cave ecosystem in the Indian sub-continent, are located at the Ananthagiri hills of Araku Valley in the Alluri district of Andhra Pradesh, India. The present investigation applied a shotgun metagenomic approach to gain insights into the microbial community structure, metabolic potential, and biosynthetic gene cluster (BGC) diversity of the microbes colonizing the surface of the speleothems from the aphotic zone of Borra caves. The taxonomic analysis of the metagenome data illustrated that the speleothem-colonizing core microbial community was dominated mainly by Alpha-, Beta-, and Gamma-Proteobacteria, Actinobacteria, Firmicutes, and Bacteroidetes. The key energy metabolic pathways analysis provides strong evidence of chemolithoautotrophic and chemoheterotrophic modes of nutrition in the speleothem-colonizing microbial community. Metagenome data suggests that sulfur reducers and sulfur-disproportionating microbes might play a vital role in energy generation in this ecosystem. Our metagenome data also suggest that the dissimilatory nitrifiers and nitrifying denitrifiers might play an essential role in conserving nitrogen pools in the ecosystem. Furthermore, metagenome-wide BGCs mining retrieved 451 putative BGCs; NRPS was the most abundant (24%). Phylogenetic analysis of the C domain of NRPS showed that sequences were distributed across all six function categories of the known C domain, including several novel subclades. For example, a novel subclade had been recovered within the LCL domain clade as a sister subclade of immunosuppressant cyclosporin encoding C domain sequences. Our result suggested that subterranean cave microbiomes might be a potential reservoir of novel microbial metabolites.
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Affiliation(s)
- Brajogopal Samanta
- Department of Microbiology and FST, GITAM School of Science, GITAM (Deemed to Be University), Rushikonda, Visakhapatnam, Andhra Pradesh, 530045, India.
| | - Shivasmi Sharma
- Bionivid Technology Private Limited, Bengaluru, Karnataka, 560043, India
| | - Roli Budhwar
- Bionivid Technology Private Limited, Bengaluru, Karnataka, 560043, India
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Xing W, Qi B, Chen R, Ding W, Zhang F. Metagenomic analysis reveals taxonomic and functional diversity of microbial communities on the deteriorated wall paintings of Qinling Tomb in the Southern Tang Dynasty, China. BMC Microbiol 2023; 23:140. [PMID: 37202728 DOI: 10.1186/s12866-023-02887-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Accepted: 05/09/2023] [Indexed: 05/20/2023] Open
Abstract
The microbial colonization on ancient murals attracts more and more attention since the threaten by microorganisms was first reported in Lascaux, Spain. However, the biodeterioration or biodegradation of mural paintings resulted by microorganisms is not clear yet. Especially the biological function of microbial communities in different conditions remained largely unaddressed. The two mausoleums of the Southern Tang Dynasty are the largest group of emperor mausoleums during the Five Dynasties and Ten Kingdoms period in China, which are of great significance to the study of the architecture, imperial mausoleum systems and art in the Tang and Song Dynasties. To make clear the species composition and metabolic functions of different microbial communities (MID and BK), we analyzed the samples from the wall paintings in one of the two mausoleums of the Southern Tang Dynasty with metagenomics method. The result showed totally 55 phyla and 1729 genera were detected in the mural paintings. The two microbial community structure were similar with the dominance of Proteobacteria, Actinobacteria and Cyanobacteria. However, the species abundance presented a significant difference between two communities at genus level --- MID is Lysobacter, Luteimonas are predominant in MID while Sphingomonas and Streptomyces are popular in BK, which is partially attributed to the different substrate materials of murals. As a result, the two communities presented the different metabolic patterns that MID community was mainly participated in the formation of biofilm as well as the degradation of exogenous pollutants while the BK was predominantly related to the photosynthesis process and biosynthesis of secondary metabolites. Taken together, these findings indicated the effect of environmental factor on the taxonomic composition and functional diversity of the microbial populations. The installation of artificial lighting needs to be considered carefully in the future protection of cultural relics.
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Affiliation(s)
- Wei Xing
- Laboratory of Environment and Health, College of Life Sciences, University of Chinese Academy of Sciences, 19A Yuquan Road, 100049, Beijing, China
| | - Binjie Qi
- Laboratory of Environment and Health, College of Life Sciences, University of Chinese Academy of Sciences, 19A Yuquan Road, 100049, Beijing, China
| | - Rulong Chen
- Laboratory of Environment and Health, College of Life Sciences, University of Chinese Academy of Sciences, 19A Yuquan Road, 100049, Beijing, China
| | - Wenjun Ding
- Laboratory of Environment and Health, College of Life Sciences, University of Chinese Academy of Sciences, 19A Yuquan Road, 100049, Beijing, China.
| | - Fang Zhang
- Laboratory of Environment and Health, College of Life Sciences, University of Chinese Academy of Sciences, 19A Yuquan Road, 100049, Beijing, China.
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Bogdan DF, Baricz AI, Chiciudean I, Bulzu PA, Cristea A, Năstase-Bucur R, Levei EA, Cadar O, Sitar C, Banciu HL, Moldovan OT. Diversity, distribution and organic substrates preferences of microbial communities of a low anthropic activity cave in North-Western Romania. Front Microbiol 2023; 14:962452. [PMID: 36825091 PMCID: PMC9941645 DOI: 10.3389/fmicb.2023.962452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Accepted: 01/17/2023] [Indexed: 02/10/2023] Open
Abstract
Introduction Karst caves are characterized by relatively constant temperature, lack of light, high humidity, and low nutrients availability. The diversity and functionality of the microorganisms dwelling in caves micro-habitats are yet underexplored. Therefore, in-depth investigations of these ecosystems aid in enlarging our understanding of the microbial interactions and microbially driven biogeochemical cycles. Here, we aimed at evaluating the diversity, abundance, distribution, and organic substrate preferences of microbial communities from Peștera cu Apă din Valea Leșului (Leșu Cave) located in the Apuseni Mountains (North-Western Romania). Materials and Methods To achieve this goal, we employed 16S rRNA gene amplicon sequencing and community-level physiological profiling (CLPP) paralleled by the assessment of environmental parameters of cave sediments and water. Results and Discussion Pseudomonadota (synonym Proteobacteria) was the most prevalent phylum detected across all samples whereas the abundance detected at order level varied among sites and between water and sediment samples. Despite the general similarity at the phylum-level in Leșu Cave across the sampled area, the results obtained in this study suggest that specific sites drive bacterial community at the order-level, perhaps sustaining the enrichment of unique bacterial populations due to microenvironmental conditions. For most of the dominant orders the distribution pattern showed a positive correlation with C-sources such as putrescine, γ-amino butyric acid, and D-malic acid, while particular cases were positively correlated with polymers (Tween 40, Tween 80 and α-cyclodextrin), carbohydrates (α-D-lactose, i-erythritol, D-mannitol) and most of the carboxylic and ketonic acids. Physicochemical analysis reveals that sediments are geochemically distinct, with increased concentration of Ca, Fe, Al, Mg, Na and K, whereas water showed low nitrate concentration. Our PCA indicated the clustering of different dominant orders with Mg, As, P, Fe, and Cr. This information serves as a starting point for further studies in elucidating the links between the taxonomic and functional diversity of subterranean microbial communities.
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Affiliation(s)
- Diana Felicia Bogdan
- Doctoral School of Integrative Biology, Faculty of Biology and Geology, Babeș-Bolyai University, Cluj-Napoca, Romania,Institute for Research, Development and Innovation in Applied Natural Sciences, Cluj-Napoca, Romania,*Correspondence: Diana Felicia Bogdan, ✉
| | - Andreea Ionela Baricz
- Department of Molecular Biology and Biotechnology, Faculty of Biology and Geology, Babeș-Bolyai University, Cluj-Napoca, Romania
| | - Iulia Chiciudean
- Department of Molecular Biology and Biotechnology, Faculty of Biology and Geology, Babeș-Bolyai University, Cluj-Napoca, Romania
| | - Paul-Adrian Bulzu
- Biology Centre CAS, Institute of Hydrobiology, Department of Aquatic Microbial Ecology, Laboratory of Microbial Ecology and Evolution, Ceske Budejovice, Czechia
| | - Adorján Cristea
- Department of Molecular Biology and Biotechnology, Faculty of Biology and Geology, Babeș-Bolyai University, Cluj-Napoca, Romania
| | - Ruxandra Năstase-Bucur
- Emil Racovita Institute of Speleology, Cluj-Napoca Department, Cluj-Napoca, Romania,Romanian Institute of Science and Technology, Cluj-Napoca, Romania
| | - Erika Andrea Levei
- INCDO-INOE 2000, Research Institute for Analytical Instrumentation, Cluj-Napoca, Romania
| | - Oana Cadar
- INCDO-INOE 2000, Research Institute for Analytical Instrumentation, Cluj-Napoca, Romania
| | - Cristian Sitar
- Romanian Institute of Science and Technology, Cluj-Napoca, Romania,Zoological Museum, Babeș-Bolyai University, Cluj-Napoca, Romania
| | - Horia Leonard Banciu
- Department of Molecular Biology and Biotechnology, Faculty of Biology and Geology, Babeș-Bolyai University, Cluj-Napoca, Romania,Centre for Systems Biology, Biodiversity and Bioresources, Faculty of Biology and Geology, Babeș-Bolyai University, Cluj-Napoca, Romania,Horia Leonard Banciu, ✉
| | - Oana Teodora Moldovan
- Emil Racovita Institute of Speleology, Cluj-Napoca Department, Cluj-Napoca, Romania,Romanian Institute of Science and Technology, Cluj-Napoca, Romania,Centro Nacional de Investigación sobre la Evolución Humana, CENIEH, Burgos, Spain
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Mizuno K, Maree M, Nagamura T, Koga A, Hirayama S, Furukawa S, Tanaka K, Morikawa K. Novel multicellular prokaryote discovered next to an underground stream. eLife 2022; 11:71920. [PMID: 36217817 PMCID: PMC9555858 DOI: 10.7554/elife.71920] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2021] [Accepted: 09/05/2022] [Indexed: 11/25/2022] Open
Abstract
A diversity of prokaryotes currently exhibit multicellularity with different generation mechanisms in a variety of contexts of ecology on Earth. In the present study, we report a new type of multicellular bacterium, HS-3, isolated from an underground stream. HS-3 self-organizes its filamentous cells into a layer-structured colony with the properties of a nematic liquid crystal. After maturation, the colony starts to form a semi-closed sphere accommodating clusters of coccobacillus daughter cells and selectively releases them upon contact with water. This is the first report that shows that a liquid-crystal status of cells can support the prokaryotic multicellular behavior. Importantly, the observed behavior of HS-3 suggests that the recurrent intermittent exposure of colonies to water flow in the cave might have been the ecological context that cultivated the evolutionary transition from unicellular to multicellular life. This is the new extant model that underpins theories regarding a role of ecological context in the emergence of multicellularity.
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Affiliation(s)
- Kouhei Mizuno
- Division of International Affairs, Headquaters, National Institute of Technology, Tokyo, Japan.,Department of Creative Engineering, National Institute of Technology, Kitakyushu, Japan
| | - Mais Maree
- Doctoral Program in Biomedical Sciences, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, Japan
| | - Toshihiko Nagamura
- Department of Creative Engineering, National Institute of Technology, Kitakyushu, Japan
| | - Akihiro Koga
- Department of Creative Engineering, National Institute of Technology, Kitakyushu, Japan
| | - Satoru Hirayama
- Department of Food Bioscience and Biotechnology, College of Bioresource Sciences, Nihon University, Fujisawa, Japan.,Division of Microbiology and Infectious Diseases, Graduate School of Medical and Dental Sciences, Niigata University, Niigata, Japan
| | - Soichi Furukawa
- Department of Food Bioscience and Biotechnology, College of Bioresource Sciences, Nihon University, Fujisawa, Japan
| | - Kenji Tanaka
- Department of Biological and Environmental Chemistry, School of Humanity-Oriented Science and Engineering, Kindai University, Iizuka, Japan
| | - Kazuya Morikawa
- Division of Biomedical Science, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
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Mudgil D, Paul D, Baskar S, Baskar R, Shouche YS. Cultivable microbial diversity in speleothems using MALDI-TOF spectrometry and DNA sequencing from Krem Soitan, Krem Lawbah, Krem Mawpun, Khasi Hills, Meghalaya, India. Arch Microbiol 2022; 204:495. [PMID: 35842875 PMCID: PMC9288962 DOI: 10.1007/s00203-022-02916-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 03/17/2022] [Accepted: 04/13/2022] [Indexed: 11/02/2022]
Abstract
AbstractThe microbial diversity in the Indian caves is inadequately characterized. This study reports on the culturable microbial communities in caves from the Indian sub-continent. This study aims to expand the current understanding of bacterial diversity in the speleothems and wall deposits from Krem Soitan, Krem Lawbah, Krem Mawpun in Khasi Hills, Meghalaya, India. A culture-dependent approach was employed for elucidating the community structure in the caves using MALDI-TOF spectrometry and 16S rRNA gene sequencing. A high bacterial diversity and a greater bacterial taxonomic diversity is reported using MALDI-TOF spectrometry and 16S rRNA gene sequencing. High microbial enumerations were observed on dilute nutrient agar (5.3 × 103 to 8.8 × 105) followed by M9 minimal medium (4 × 104 to 1.7 × 105) and R2A medium (1.0 × 104 to 5.7 × 105). A total of 826 bacterial isolates were selected and preserved for the study. 295 bacterial isolates were identified using MALDI-TOF spectrometry and the isolates which showed no reliable peaks were further identified by 16S rRNA gene sequencing. A total 91% of the bacterial diversity was dominated by Proteobacteria (61%) and Actinobacteria (30%). In addition, bacterial phyla include Firmicutes (7.45%), Deinococcus-Thermus (0.33%) and Bacteroidetes (0.67%) were found in the samples. At the genus level, Pseudomonas (55%) and Arthrobacter (23%) were ubiquitous followed by Acinetobacter, Bacillus, Brevundimonas, Deinococcus, Flavobacterium, Paenibacillus, Pseudarthrobacter. Multivariate statistical analysis indicated that the bacterial genera formed separate clusters depending on the geochemical constituents in the spring waters suitable for their growth and metabolism. To the best of our knowledge, there are no previous geomicrobiological investigations in these caves and this study is a pioneering culture dependent study of the microbial community with many cultured isolates.
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Cahoon AB, VanGundy RD. Alveolates (dinoflagellates, ciliates and apicomplexans) and Rhizarians are the most common microbial eukaryotes in temperate Appalachian karst caves. ENVIRONMENTAL MICROBIOLOGY REPORTS 2022; 14:538-548. [PMID: 35388620 PMCID: PMC9542216 DOI: 10.1111/1758-2229.13060] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Revised: 03/02/2022] [Accepted: 03/10/2022] [Indexed: 06/14/2023]
Abstract
The purpose of this study was to survey the eukaryotic microbiome of two karst caves in the Valley and Ridge physiographic region of the Appalachian Mountains. Caves are known to harbour eukaryotic microbes but their very low densities and small cell size make them difficult to collect and identify. Microeukaryotes were surveyed using two methodologies, filtering water and submerging glass microscope slides mounted in periphytometers in cave pools. The periphyton sampling yielded 13.5 times more unique amplicon sequence variants (ASVs) than filtered water. The most abundant protist supergroup was Alveolata with large proportions of the ASVs belonging to dinoflagellate, ciliate and apicomplexan clades. The next most abundant were Rhizarians followed by Stramenopiles (diatoms and chrysophytes) and Ameobozoans. Very few of the ASVs, 1.5%, matched curated protist sequences with greater than 99% identity and only 2.5% could be identified from surface plankton samples collected in the same region. The overall composition of the eukaryotic microbiome appears to be a combination of bacterial grazers and parasitic species that could possibly survive underground as well as cells, cysts and spores probably transported from the surface.
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Affiliation(s)
- A. Bruce Cahoon
- Department of Natural SciencesThe University of Virginia's College at WiseWiseVA24293USA
| | - Robert D. VanGundy
- Department of Natural SciencesThe University of Virginia's College at WiseWiseVA24293USA
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Wang Y, Cheng X, Wang H, Zhou J, Liu X, Tuovinen OH. The Characterization of Microbiome and Interactions on Weathered Rocks in a Subsurface Karst Cave, Central China. Front Microbiol 2022; 13:909494. [PMID: 35847118 PMCID: PMC9277220 DOI: 10.3389/fmicb.2022.909494] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Accepted: 05/19/2022] [Indexed: 11/13/2022] Open
Abstract
Karst caves are a natural oligotrophic subsurface biosphere widely distributed in southern China. Despite the progress in bacterial and fungal diversity, the knowledge about interactions between bacteria, fungi, and minerals is still limited in caves. Hence, for the first time, we investigated the interaction between bacteria and fungi living on weathered rocks in the Heshang Cave via high-throughput sequencing of 16S rRNA and ITS1 genes, and co-occurrence analysis. The mineral compositions of weathered rocks were analyzed by X-ray diffraction. Bacterial communities were dominated by Actinobacteria (33.68%), followed by Alphaproteobacteria (8.78%), and Planctomycetia (8.73%). In contrast, fungal communities were dominated by Sordariomycetes (21.08%) and Dothideomycetes (14.06%). Mineral substrata, particularly phosphorus-bearing minerals, significantly impacted bacterial (hydroxyapatite) and fungal (fluorapatite) communities as indicated by the redundancy analysis. In comparison with fungi, the development of bacterial communities was more controlled by the environmental selection indicated by the overwhelming contribution of deterministic processes. Co-occurrence network analysis showed that all nodes were positively linked, indicating ubiquitous cooperation within bacterial groups and fungal groups, as well as between bacteria and fungi under oligotrophic conditions in the subsurface biosphere. In total, 19 bacterial ASVs and 34 fungal OTUs were identified as keystone taxa, suggesting the fundamental role of fungi in maintaining the microbial ecosystem on weathered rocks. Ascomycota was most dominant in keystone taxa, accounting for 26.42%, followed by Actinobacteria in bacteria (24.53%). Collectively, our results confirmed the highly diverse bacterial and fungal communities on weathered rocks, and their close cooperation to sustain the subsurface ecosystem. Phosphorus-bearing minerals were of significance in shaping epipetreous bacterial and fungal communities. These observations provide new knowledge about microbial interactions between bacteria, fungi, and minerals in the subterranean biosphere.
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Affiliation(s)
- Yiheng Wang
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, China.,School of Environmental Studies, China University of Geosciences, Wuhan, China
| | - Xiaoyu Cheng
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, China.,School of Environmental Studies, China University of Geosciences, Wuhan, China
| | - Hongmei Wang
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, China.,School of Environmental Studies, China University of Geosciences, Wuhan, China
| | - Jianping Zhou
- School of Environmental Studies, China University of Geosciences, Wuhan, China
| | - Xiaoyan Liu
- School of Environmental Studies, China University of Geosciences, Wuhan, China
| | - Olli H Tuovinen
- Department of Microbiology, The Ohio State University, Columbus, OH, United States
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Phylotypic Diversity of Bacteria Associated with Speleothems of a Silicate Cave in a Guiana Shield Tepui. Microorganisms 2022; 10:microorganisms10071395. [PMID: 35889113 PMCID: PMC9316562 DOI: 10.3390/microorganisms10071395] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 06/21/2022] [Accepted: 07/07/2022] [Indexed: 12/22/2022] Open
Abstract
The diversity of microorganisms associated with speleological sources has mainly been studied in limestone caves, while studies in silicate caves are still under development. Here, we profiled the microbial diversity of opal speleothems from a silicate cave in Guiana Highlands. Bulk DNAs were extracted from three speleothems of two types, i.e., one soft whitish mushroom-like speleothem and two hard blackish coral-like speleothems. The extracted DNAs were amplified for sequencing the V3–V4 region of the bacterial 16S rRNA gene by MiSeq. A total of 210,309 valid reads were obtained and clustered into 3184 phylotypes or operational taxonomic units (OTUs). The OTUs from the soft whitish speleothem were mostly affiliated with Acidobacteriota, Pseudomonadota (formerly, Proteobacteria), and Chloroflexota, with the OTUs ascribed to Nitrospirota being found specifically in this speleothem. The OTUs from the hard blackish speleothems were similar to each other and were mostly affiliated with Pseudomonadota, Acidobacteriota, and Actinomycetota (formerly, Actinobacteria). These OTU compositions were generally consistent with those reported for limestone and silicate caves. The OTUs were further used to infer metabolic features by using the PICRUSt bioinformatic tool, and membrane transport and amino acid metabolism were noticeably featured. These and other featured metabolisms may influence the pH microenvironment and, consequently, the formation, weathering, and re-deposition of silicate speleothems.
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Koning K, McFarlane R, Gosse JT, Lawrence S, Carr L, Horne D, Van Wagoner N, Boddy CN, Cheeptham N. Biomineralization in Cave Bacteria—Popcorn and Soda Straw Crystal Formations, Morphologies, and Potential Metabolic Pathways. Front Microbiol 2022; 13:933388. [PMID: 35847116 PMCID: PMC9283089 DOI: 10.3389/fmicb.2022.933388] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Accepted: 05/25/2022] [Indexed: 11/29/2022] Open
Abstract
Caves are extreme, often oligotrophic, environments that house diverse groups of microorganisms. Many of these microbes can perform microbiologically induced carbonate precipitation (MICP) to form crystalline secondary cave deposits known as speleothems. The urease family is a group of enzymes involved in MICP that catalyze the breakdown of urea, which is a source of energy, into ammonia and carbonate. Carbonate anions are effluxed to the extracellular surface of the bacterium where it then binds to environmental calcium to form calcium carbonate which then continues to grow in crystal form. Here, we studied bacterial communities from speleothems collected from the Iron Curtain Cave (ICC) in Chilliwack, B.C., Canada, to characterize these organisms and determine whether urease-positive (U+) bacteria were present in the cave and their potential impact on speleothem formation. The ICC is a carbonate cave located on the northside of Chipmunk Ridge, presenting a unique environment with high iron content sediment and limestone structures throughout. With six pools of water throughout the cave, the environment is highly humid, with temperatures ranging between 4 and 12°C depending on the time of year. Ninety-nine bacterial strains were isolated from popcorn (PCS) and soda straw (SSS) speleothems. These isolates were screened for urease enzymatic activity, with 11 candidates found to be urease-positive. After incubation, species-specific crystal morphologies were observed. Popcorn speleothem provided more bacterial diversity overall when compared to soda straw speleothem when examined under a culture-based method. Nearly twice as many U+ isolates were isolated from popcorn speleothems compared to soda straw speleothems. The U+ candidates were identified to the genus level by 16S rRNA analysis, and two isolates underwent whole-genome sequencing. Two novel species were identified as Sphingobacterium sp. PCS056 and Pseudarthrobacter sp. SSS035. Both isolates demonstrated the most crystal production as well as the most morphologically dissimilar crystal shapes in broth culture and were found to produce crystals as previously observed in both agar and broth media. The results from this study are consistent with the involvement of urease-positive bacteria isolated from the ICC in the formation of cave speleothems. 16S rRNA sequencing revealed a diverse set of microbes inhabiting the speleothems that have urease activity. Whole-genome sequencing of the two chosen isolates confirmed the presence of urease pathways, while revealing differences in urease pathway structure and number. This research contributes to understanding microbial-associated cave formation and degradation, with applications to cave conservation, microbiota composition, and their role in shaping the cave environment.
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Affiliation(s)
- Keegan Koning
- Department of Biology, Faculty of Science, Thompson Rivers University, Kamloops, BC, Canada
| | - Richenda McFarlane
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON, Canada
| | - Jessica T. Gosse
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON, Canada
| | - Sara Lawrence
- Department of Biology, Faculty of Science, Thompson Rivers University, Kamloops, BC, Canada
| | - Lynnea Carr
- Department of Biology, Faculty of Science, Thompson Rivers University, Kamloops, BC, Canada
| | - Derrick Horne
- The University of British Columbia Bioimaging Facility, Biological Sciences Building, Vancouver, BC, Canada
| | - Nancy Van Wagoner
- Department of Physical Sciences, Faculty of Science, Thompson Rivers University, Kamloops, BC, Canada
| | - Christopher N. Boddy
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON, Canada
| | - Naowarat Cheeptham
- Department of Biology, Faculty of Science, Thompson Rivers University, Kamloops, BC, Canada
- *Correspondence: Naowarat Cheeptham,
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Ai J, Guo J, Li Y, Zhong X, Lv Y, Li J, Yang A. The diversity of microbes and prediction of their functions in karst caves under the influence of human tourism activities-a case study of Zhijin Cave in Southwest China. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:25858-25868. [PMID: 34854002 DOI: 10.1007/s11356-021-17783-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Accepted: 11/23/2021] [Indexed: 06/13/2023]
Abstract
Microorganisms, sensitive to the surrounding environment changes, show how the cave environment can be impacted by human activities. Zhijin Cave, featured with the most well-developed karst landform in China, has been open to tourists for more than 30 years. This study explored the microbial diversity in a karst cave and the impacts of tourism activities on the microbial communities and the community structures of bacteria and archaea in three niches in Zhijin Cave, including the mixture of bacteria and cyanobacteria on the rock wall, the aquatic sediments, and the surface sediments, using 16S rRNA high-throughput sequencing technology. It was found that Actinobacteriota and Proteobacteria were the dominant bacteria in the cave and Crenarchaeota and Thermoplasmatota were the dominant archaea. The correlation between microorganisms and environmental variables in the cave showed that archaea were more affected by pH and ORP than bacteria and F-, Cl-, NO3-, and SO42- were all positively relevant to the distribution of most bacteria and archaea in the cave. PICRUSt's prediction of microbial functions also indicated that abundance of the bacteria's functions was higher than that of the archaea. The intention of this study was to improve the understanding, development, and protection of microbial resources in caves.
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Affiliation(s)
- Jia Ai
- College of Resources and Environmental Engineering, Key Laboratory of Karst Georesources and Environment, Ministry of Education, Guizhou University, Guiyang, 500025, China
| | - Jianeng Guo
- Management Office of Zhijin Cave Scenic Area, Bijie, 552100, Guizhou, China
| | - Yancheng Li
- College of Resources and Environmental Engineering, Key Laboratory of Karst Georesources and Environment, Ministry of Education, Guizhou University, Guiyang, 500025, China.
- Guizhou Karst Environmental Ecosystems Observation and Research Station, Ministry of Education, Guiyang, 550025, Guizhou, China.
| | - Xiong Zhong
- College of Resources and Environmental Engineering, Key Laboratory of Karst Georesources and Environment, Ministry of Education, Guizhou University, Guiyang, 500025, China
| | - Yang Lv
- College of Resources and Environmental Engineering, Key Laboratory of Karst Georesources and Environment, Ministry of Education, Guizhou University, Guiyang, 500025, China
| | - Jiang Li
- College of Resources and Environmental Engineering, Key Laboratory of Karst Georesources and Environment, Ministry of Education, Guizhou University, Guiyang, 500025, China
- Guizhou Karst Environmental Ecosystems Observation and Research Station, Ministry of Education, Guiyang, 550025, Guizhou, China
| | - Aijiang Yang
- College of Resources and Environmental Engineering, Key Laboratory of Karst Georesources and Environment, Ministry of Education, Guizhou University, Guiyang, 500025, China
- Guizhou Karst Environmental Ecosystems Observation and Research Station, Ministry of Education, Guiyang, 550025, Guizhou, China
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11
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Zada S, Xie J, Yang M, Yang X, Sajjad W, Rafiq M, Hasan F, Hu Z, Wang H. Composition and functional profiles of microbial communities in two geochemically and mineralogically different caves. Appl Microbiol Biotechnol 2021; 105:8921-8936. [PMID: 34738169 DOI: 10.1007/s00253-021-11658-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 10/17/2021] [Accepted: 10/22/2021] [Indexed: 12/18/2022]
Abstract
Microbial communities in cave ecosystems have specific survival strategies, which is far from being well explicated. Here, we reported the genetic and functional diversity of bacteria and archaea in typical limestone (Kashmir Cave) and silicate-containing (Tiser Cave) caves. X-ray diffraction (XRD) and Fourier transform infrared spectroscopic (FTIR) analyses revealed the different geochemical and mineral compositions of the two caves. Amplicon barcode sequencing revealed the dominancy of Actinobacteria and Proteobacteria in Kashmir and Tiser Caves. Bacteroidetes and Firmicutes were the dominant phyla in Tiser Cave, and the abundance is relatively small in Kashmir Cave. Archaea was also abundant prokaryotes in Kashmir Cave, but it only accounted for 0.723% of the total prokaryote sequences in Tiser Cave. Functional analysis based on metagenomic sequencing data revealed that a large number of functional potential genes involved in nutrient metabolism and biosynthesis of bioactive compounds in Tiser and Kashmir Cave samples could significantly influence the biogeochemical cycle and secondary metabolite production in cave habitats. In addition, the two caves were also found to be rich in biosynthetic genes, encoding bioactive compounds, such as monobactam and prodigiosin, indicating that these caves could be potential habitats for the isolation of antibiotics. This study provides a comprehensive insight into the diversity of bacteria and archaea in cave ecosystems and helps to better understand the special survival strategies of microorganisms in cave ecosystems.Key points• Geochemically distinct caves possess unique microbial community structure.• Cavernicoles could be important candidates for antibiotic production.• Cavernicoles are important for biogeochemical cycling.
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Affiliation(s)
- Sahib Zada
- Department of Biology, College of Science, Guangdong Provincial Key Laboratory of Marine Biotechnology, Institute of Marine Sciences, Shantou University, Shantou, China
| | - Jianmin Xie
- Department of Biology, College of Science, Guangdong Provincial Key Laboratory of Marine Biotechnology, Institute of Marine Sciences, Shantou University, Shantou, China
| | - Min Yang
- Department of Biology, College of Science, Guangdong Provincial Key Laboratory of Marine Biotechnology, Institute of Marine Sciences, Shantou University, Shantou, China
| | - Xiaoyu Yang
- Department of Biology, College of Science, Guangdong Provincial Key Laboratory of Marine Biotechnology, Institute of Marine Sciences, Shantou University, Shantou, China
| | - Wasim Sajjad
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, 730000, China
| | - Muhammad Rafiq
- Department of Microbiology, Faculty of Life Sciences and Informatics, Engineering and Management Sciences, Balochistan University of Information Technology, Quetta, Pakistan
| | - Fariha Hasan
- Department of Microbiology, Quaid-I-Azam University, Islamabad, Pakistan
| | - Zhong Hu
- Department of Biology, College of Science, Guangdong Provincial Key Laboratory of Marine Biotechnology, Institute of Marine Sciences, Shantou University, Shantou, China
| | - Hui Wang
- Department of Biology, College of Science, Guangdong Provincial Key Laboratory of Marine Biotechnology, Institute of Marine Sciences, Shantou University, Shantou, China.
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12
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Microbial Interactions Drive Distinct Taxonomic and Potential Metabolic Responses to Habitats in Karst Cave Ecosystem. Microbiol Spectr 2021; 9:e0115221. [PMID: 34494852 PMCID: PMC8557908 DOI: 10.1128/spectrum.01152-21] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The geological role of microorganisms has been widely studied in the karst cave ecosystem. However, microbial interactions and ecological functions in such a dark, humid, and oligotrophic habitat have received far less attention, which is crucial to understanding cave biogeochemistry. Herein, microorganisms from weathered rock and sediment along the Heshang Cave depth were analyzed by random matrix theory-based network and Tax4Fun functional prediction. The results showed that although the cave microbial communities have spatial heterogeneity, differential habitats drove the community structure and diversity. Actinobacteria were predominant in weathered rock, whereas Proteobacteria dominated the sediment. The sediment communities presented significantly higher alpha diversities due to the relatively abundant nutrition from the outside by the intermittent stream. Consistently, microbial interactions in sediment were more complex, as visualized by more nodes and links. The abundant taxa presented more positive correlations with other community members in both of the two networks, indicating that they relied on promotion effects to adapt to the extreme environment. The keystones in weathered rock were mainly involved in the biodegradation of organic compounds, whereas the keystone Nitrospira in sediment contributed to carbon/nitrogen fixation. Collectively, these findings suggest that microbial interactions may lead to distinct taxonomic and functional communities in weathered rock and sediment in the subsurface Heshang Cave. IMPORTANCE In general, the constant physicochemical conditions and limited nutrient sources over long periods in the subsurface support a stable ecosystem in karst cave. Previous studies on cave microbial ecology were mostly focused on community composition, diversity, and the relationship with local environmental factors. There are still many unknowns about the microbial interactions and functions in such a dark environment with little human interference. Two representative habitats, including weathered rock and sediment in Heshang Cave, were selected to give an integrated insight into microbial interactions and potential functions. The cooccurrence network, especially the subnetwork, was used to characterize the cave microbial interactions in detail. We demonstrated that abundant taxa primarily relied on promotion effects rather than inhibition effects to survive in Heshang Cave. Keystone species may play important metabolic roles in sustaining ecological functions. Our study provides improved understanding of microbial interaction patterns and community ecological functions in the karst cave ecosystem.
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13
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Lampenflora in a Show Cave in the Great Basin Is Distinct from Communities on Naturally Lit Rock Surfaces in Nearby Wild Caves. Microorganisms 2021; 9:microorganisms9061188. [PMID: 34072861 PMCID: PMC8227912 DOI: 10.3390/microorganisms9061188] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2021] [Revised: 05/26/2021] [Accepted: 05/27/2021] [Indexed: 12/31/2022] Open
Abstract
In show caves, artificial lighting is intended to illuminate striking cave formations for visitors. However, artificial lighting also promotes the growth of novel and diverse biofilm communities, termed lampenflora, that obtain their energy from these artificial light sources. Lampenflora, which generally consist of cyanobacteria, algae, diatoms, and bryophytes, discolor formations and introduce novel ecological interactions in cave ecosystems. The source of lampenflora community members and patterns of diversity have generally been understudied mainly due to technological limitations. In this study, we investigate whether members of lampenflora communities in an iconic show cave—Lehman Caves—in Great Basin National Park (GRBA) in the western United States also occur in nearby unlit and rarely visited caves. Using a high-throughput environmental DNA metabarcoding approach targeting three loci—the ITS2 (fungi), a fragment of the 16S (bacteria), and a fragment of 23S (photosynthetic bacteria and eukaryotes)—we characterized diversity of lampenflora communities occurring near artificial light sources in Lehman Caves and rock surfaces near the entrances of seven nearby “wild” caves. Most caves supported diverse and distinct microbial-dominated communities, with little overlap in community members among caves. The lampenflora communities in the show cave were distinct, and generally less diverse, from those occurring in nearby unlit caves. Our results suggest an unidentified source for a significant proportion of lampenflora community members in Lehman Caves, with the majority of community members not found in nearby wild caves. Whether the unique members of the lampenflora communities in Lehman Caves are related to distinct abiotic conditions, increased human visitation, or other factors remains unknown. These results provide a valuable framework for future research exploring lampenflora community assemblies in show caves, in addition to a broad perspective into the range of microbial and lampenflora community members in GRBA. By more fully characterizing these communities, we can better monitor the establishment of lampenflora and design effective strategies for their management and removal.
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14
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Selim MSM, Abdelhamid SA, Mohamed SS. Secondary metabolites and biodiversity of actinomycetes. J Genet Eng Biotechnol 2021; 19:72. [PMID: 33982192 PMCID: PMC8116480 DOI: 10.1186/s43141-021-00156-9] [Citation(s) in RCA: 57] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Accepted: 03/29/2021] [Indexed: 11/10/2022]
Abstract
BACKGROUND The ability to produce microbial bioactive compounds makes actinobacteria one of the most explored microbes among prokaryotes. The secondary metabolites of actinobacteria are known for their role in various physiological, cellular, and biological processes. MAIN BODY Actinomycetes are widely distributed in natural ecosystem habitats such as soil, rhizosphere soil, actinmycorrhizal plants, hypersaline soil, limestone, freshwater, marine, sponges, volcanic cave-hot spot, desert, air, insects gut, earthworm castings, goat feces, and endophytic actinomycetes. The most important features of microbial bioactive compounds are that they have specific microbial producers: their diverse bioactivities and their unique chemical structures. Actinomycetes represent a source of biologically active secondary metabolites like antibiotics, biopesticide agents, plant growth hormones, antitumor compounds, antiviral agents, pharmacological compounds, pigments, enzymes, enzyme inhibitors, anti-inflammatory compounds, single-cell protein feed, and biosurfactant. SHORT CONCLUSIONS Further highlight that compounds derived from actinobacteria can be applied in a wide range of industrial applications in biomedicines and the ecological habitat is under-explored and yet to be investigated for unknown, rare actinomycetes diversity.
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Affiliation(s)
- Manal Selim Mohamed Selim
- Microbial Biotechnology Department—Genetic Engineering Division, National Research Centre, Giza, Egypt
| | | | - Sahar Saleh Mohamed
- Microbial Biotechnology Department—Genetic Engineering Division, National Research Centre, Giza, Egypt
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15
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Morse KV, Richardson DR, Brown TL, Vangundy RD, Cahoon AB. Longitudinal metabarcode analysis of karst bacterioplankton microbiomes provide evidence of epikarst to cave transport and community succession. PeerJ 2021; 9:e10757. [PMID: 33732542 PMCID: PMC7950216 DOI: 10.7717/peerj.10757] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Accepted: 12/21/2020] [Indexed: 01/04/2023] Open
Abstract
Caves are often assumed to be static environments separated from weather changes experienced on the surface. The high humidity and stability of these subterranean environments make them attractive to many different organisms including microbes such as bacteria and protists. Cave waters generally originate from the surface, may be filtered by overlying soils, can accumulate in interstitial epikarst zones underground, and emerge in caves as streams, pools and droplets on speleothems. Water movement is the primary architect of karst caves, and depending on the hydrologic connectivity between surface and subsurface, is the most likely medium for the introduction of microbes to caves. Recently published metabarcoding surveys of karst cave soils and speleothems have suggested that the vast majority of bacteria residing in these habitats do not occur on the surface, calling into question the role of microbial transport by surface waters. The purpose of this study was to use metabarcoding to monitor the aquatic prokaryotic microbiome of a cave for 1 year, conduct longitudinal analyses of the cave's aquatic bacterioplankton, and compare it to nearby surface water. Water samples were collected from two locations inside Panel Cave in Natural Tunnel State Park in Duffield, VA and two locations outside of the cave. Of the two cave locations, one was fed by groundwater and drip water and the other by infiltrating surface water. A total of 1,854 distinct prokaryotic ASVs were detected from cave samples and 245 (13.1%) were not found in surface samples. PCo analysis demonstrated a marginal delineation between two cave sample sites and between cave and surface microbiomes suggesting the aquatic bacterioplankton in a karst cave is much more similar to surface microbes than reported from speleothems and soils. Most surprisingly, there was a cave microbe population and diversity bloom in the fall months whereas biodiversity remained relatively steady on the surface. The cave microbiome was more similar to the surface before the bloom than during and afterwards. This event demonstrates that large influxes of bacteria and particulate organic matter can enter the cave from either the surface or interstitial zones and the divergence of the cave microbiome from the surface demonstrates movement of microbes from the epikarst zones into the cave.
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16
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Bacteria and Metabolic Potential in Karst Caves Revealed by Intensive Bacterial Cultivation and Genome Assembly. Appl Environ Microbiol 2021; 87:AEM.02440-20. [PMID: 33452024 DOI: 10.1128/aem.02440-20] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Accepted: 01/05/2021] [Indexed: 12/26/2022] Open
Abstract
Karst caves are widely distributed subsurface systems, and the microbiomes therein are proposed to be the driving force for cave evolution and biogeochemical cycling. In past years, culture-independent studies on the microbiomes of cave systems have been conducted, yet intensive microbial cultivation is still needed to validate the sequence-derived hypothesis and to disclose the microbial functions in cave ecosystems. In this study, the microbiomes of two karst caves in Guizhou Province in southwest China were examined. A total of 3,562 bacterial strains were cultivated from rock, water, and sediment samples, and 329 species (including 14 newly described species) of 102 genera were found. We created a cave bacterial genome collection of 218 bacterial genomes from a karst cave microbiome through the extraction of 204 database-derived genomes and de novo sequencing of 14 new bacterial genomes. The cultivated genome collection obtained in this study and the metagenome data from previous studies were used to investigate the bacterial metabolism and potential involvement in the carbon, nitrogen, and sulfur biogeochemical cycles in the cave ecosystem. New N2-fixing Azospirillum and alkane-oxidizing Oleomonas species were documented in the karst cave microbiome. Two pcaIJ clusters of the β-ketoadipate pathway that were abundant in both the cultivated microbiomes and the metagenomic data were identified, and their representatives from the cultivated bacterial genomes were functionally demonstrated. This large-scale cultivation of a cave microbiome represents the most intensive collection of cave bacterial resources to date and provides valuable information and diverse microbial resources for future cave biogeochemical research.IMPORTANCE Karst caves are oligotrophic environments that are dark and humid and have a relatively stable annual temperature. The diversity of bacteria and their metabolisms are crucial for understanding the biogeochemical cycling in cave ecosystems. We integrated large-scale bacterial cultivation with metagenomic data mining to explore the compositions and metabolisms of the microbiomes in two karst cave systems. Our results reveal the presence of a highly diversified cave bacterial community, and 14 new bacterial species were described and their genomes sequenced. In this study, we obtained the most intensive collection of cultivated microbial resources from karst caves to date and predicted the various important routes for the biogeochemical cycling of elements in cave ecosystems.
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17
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Cirigliano A, Mura F, Cecchini A, Tomassetti MC, Maras DF, Di Paola M, Meriggi N, Cavalieri D, Negri R, Quagliariello A, Hallsworth JE, Rinaldi T. Active microbial ecosystem in
Iron‐Age
tombs of the Etruscan civilization. Environ Microbiol 2020; 23:3957-3969. [DOI: 10.1111/1462-2920.15327] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Revised: 11/13/2020] [Accepted: 11/14/2020] [Indexed: 12/18/2022]
Affiliation(s)
- Angela Cirigliano
- Department of Biology and Biotechnology Sapienza University of Rome Rome Italy
| | - Francesco Mura
- CNIS – Center for Nanotechnology Applied to Industry of La Sapienza Sapienza University of Rome Rome Italy
| | - Adele Cecchini
- Associazione No Profit ‘Amici Delle Tombe Dipinte di Tarquinia’ Tarquinia Italy
| | | | - Daniele Federico Maras
- Soprintendenza Archeologia Belle Arti e Paesaggio per l'Area Metropolitana di Roma, la Provincia di Viterbo e l'Etruria Meridionale Ministero dei Beni e delle Attività Culturali e del Turismo Rome Italy
| | | | | | | | - Rodolfo Negri
- Department of Biology and Biotechnology Sapienza University of Rome Rome Italy
| | - Andrea Quagliariello
- Department of Comparative Biomedicine and Food Science University of Padova Padova Italy
| | - John E. Hallsworth
- Institute for Global Food Security School of Biological Sciences, Queen's University Belfast Belfast UK
| | - Teresa Rinaldi
- Department of Biology and Biotechnology Sapienza University of Rome Rome Italy
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18
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Ando K, Murakami T. Detection of human-associated bacteria in water from Akiyoshi-do Cave, Japan. WATER ENVIRONMENT RESEARCH : A RESEARCH PUBLICATION OF THE WATER ENVIRONMENT FEDERATION 2020; 92:1866-1873. [PMID: 32386088 DOI: 10.1002/wer.1355] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Revised: 04/11/2020] [Accepted: 04/28/2020] [Indexed: 06/11/2023]
Abstract
Akiyoshi-do Cave is one of the oldest and the largest show caves in Japan. Environmental alterations induced by tourism impacts have been suggested; however, only a few previous studies have investigated the impacts of tourism on the cave. In this study, enrichment culture procedures were applied to detect human-associated bacteria (HAB) including Escherichia coli, Staphylococcus aureus, and thermo-tolerant Bacillus spp. in cave water. Physical and bacterial parameters of water including total nitrogen, ammonia, phosphate, total number of bacteria, and total number of viable bacteria were collected as environmental factors. Escherichia coli was absent at all sites, but increased levels of total bacteria, viable bacteria, S. aureus, and thermo-tolerant Bacillus spp. were present at high-impact sites. Examination of the origin tracking of HAB suggested that cave tourists could be a source of HAB contamination, but other causes related to the surface land use could also contribute to HAB contamination. © 2020 Water Environment Federation PRACTITIONER POINTS: Detection of HAB was performed for the first time in Japanese show caves to consider tourism impacts. The greater number of HAB was detected from the tourist area than the nontourist area in the cave. It was suggested that the origin of HAB may not be limited to tourists, but may also include the surface.
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Affiliation(s)
- Kanato Ando
- Graduate School of Frontier Sciences, The University of Tokyo, Chiba, Japan
| | - Takashi Murakami
- Mine City Board of Education, Cultural Property Protection Division, Yamaguchi, Japan
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19
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Dong Y, Gao J, Wu Q, Ai Y, Huang Y, Wei W, Sun S, Weng Q. Co-occurrence pattern and function prediction of bacterial community in Karst cave. BMC Microbiol 2020; 20:137. [PMID: 32471344 PMCID: PMC7257168 DOI: 10.1186/s12866-020-01806-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Accepted: 04/28/2020] [Indexed: 01/20/2023] Open
Abstract
Background Karst caves are considered as extreme environments with nutrition deficiency, darkness, and oxygen deprivation, and they are also the sources of biodiversity and metabolic pathways. Microorganisms are usually involved in the formation and maintenance of the cave system through various metabolic activities, and are indicators of changes environment influenced by human. Zhijin cave is a typical Karst cave and attracts tourists in China. However, the bacterial diversity and composition of the Karst cave are still unclear. The present study aims to reveal the bacterial diversity and composition in the cave and the potential impact of tourism activities, and better understand the roles and co-occurrence pattern of the bacterial community in the extreme cave habitats. Results The bacterial community consisted of the major Proteobacteria, Actinobacteria, and Firmicutes, with Proteobacteria being the predominant phylum in the rock, soil, and stalactite samples. Compositions and specialized bacterial phyla of the bacterial communities were different among different sample types. The highest diversity index was found in the rock samples with a Shannon index of 4.71. Overall, Zhijin cave has relatively lower diversity than that in natural caves. The prediction of function showed that various enzymes, including ribulose-bisphosphate carboxylase, 4-hydroxybutyryl-CoA dehydratase, nitrogenase NifH, and Nitrite reductase, involved in carbon and nitrogen cycles were detected in Zhijin cave. Additionally, the modularity indices of all co-occurrence network were greater than 0.40 and the species interactions were complex across different sample types. Co-occurring positive interactions in the bacteria groups in different phyla were also observed. Conclusion These results uncovered that the oligotrophic Zhijin cave maintains the bacterial communities with the diverse metabolic pathways, interdependent and cooperative co-existence patterns. Moreover, as a hotspot for tourism, the composition and diversity of bacterial community are influenced by tourism activities. These afford new insights for further exploring the adaptation of bacteria to extreme environments and the conservation of cave ecosystem.
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Affiliation(s)
- Yiyi Dong
- School of Life Sciences, Guizhou Normal University, Guiyang, 550001, Guizhou, China.,CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, 666303, Yunnan, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Jie Gao
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, 666303, Yunnan, China.,Center of Conservation Biology, Core Botanical Gardens, Chinese Academy of Sciences, Mengla, 666303, Yunnan, China
| | - Qingshan Wu
- School of Life Sciences, Guizhou Normal University, Guiyang, 550001, Guizhou, China
| | - Yilang Ai
- School of Life Sciences, Guizhou Normal University, Guiyang, 550001, Guizhou, China
| | - Yu Huang
- School of Life Sciences, Guizhou Normal University, Guiyang, 550001, Guizhou, China
| | - Wenzhang Wei
- School of Life Sciences, Guizhou Normal University, Guiyang, 550001, Guizhou, China.,Department of Bioengineering and Biotechnology, Huaqiao University, Xiamen, 361021, Fujian, China
| | - Shiyu Sun
- School of Life Sciences, Guizhou Normal University, Guiyang, 550001, Guizhou, China
| | - Qingbei Weng
- School of Life Sciences, Guizhou Normal University, Guiyang, 550001, Guizhou, China.
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20
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Park S, Cho YJ, Jung DY, Jo KN, Lee EJ, Lee JS. Microbial Diversity in Moonmilk of Baeg-nyong Cave, Korean CZO. Front Microbiol 2020; 11:613. [PMID: 32390967 PMCID: PMC7190796 DOI: 10.3389/fmicb.2020.00613] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2019] [Accepted: 03/19/2020] [Indexed: 11/17/2022] Open
Abstract
The Baeg-nyong cave is a limestone cave which has been nominated as the first critical zone observatory (CZO) in South Korea. Moonmilk is a well-known speleothem composed of various carbonate minerals. To characterize moonmilk from the Baeg-nyong cave, we performed mineralogical analyses and applied high-throughput 16S rRNA gene sequencing to analyze the microbial communities, including bacteria and fungi, of dry and wet moonmilk samples. The results showed that the dry and wet moonmilk samples had different and atypical crystal structures, although they were predominantly composed of CaCO3. Furthermore, metagenomic data revealed that the dry and wet moonmilk samples collected from an oligotrophic environment had completely different bacterial communities when compared to the outside soil, and there was a difference in bacterial communities even between dry and wet moonmilk specimens. Fungal communities, however, did not differ significantly between dry and wet moonmilk samples. This study is the first metagenomic analysis of two different types of moonmilk with different physical properties and the first report on the microbial diversity of moonmilk from a cave in the first CZO in South Korea.
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Affiliation(s)
- Shinae Park
- Department of Molecular Bioscience, College of Biomedical Science, Kangwon National University, Chuncheon, South Korea
- Critical Zone Frontier Research Laboratory, Kangwon National University, Chuncheon, South Korea
| | - Yong-Joon Cho
- School of Biological Sciences and Research Institute of Basic Sciences, Seoul National University, Seoul, South Korea
| | - Da-yea Jung
- Critical Zone Frontier Research Laboratory, Kangwon National University, Chuncheon, South Korea
- Division of Geology and Geophysics, College of Natural Sciences, Chuncheon, South Korea
| | - Kyung-nam Jo
- Critical Zone Frontier Research Laboratory, Kangwon National University, Chuncheon, South Korea
- Division of Geology and Geophysics, College of Natural Sciences, Chuncheon, South Korea
| | - Eun-Jin Lee
- Department of Life Sciences, Korea University, Seoul, South Korea
| | - Jung-Shin Lee
- Department of Molecular Bioscience, College of Biomedical Science, Kangwon National University, Chuncheon, South Korea
- Critical Zone Frontier Research Laboratory, Kangwon National University, Chuncheon, South Korea
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21
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Mihajlovski A, Lepinay C, Mirval AL, Touron S, Bousta F, Di Martino P. Characterization of the archaeal and fungal diversity associated with gypsum efflorescences on the walls of the decorated Sorcerer’s prehistoric cave. ANN MICROBIOL 2019. [DOI: 10.1007/s13213-019-01506-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
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22
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Zhu HZ, Zhang ZF, Zhou N, Jiang CY, Wang BJ, Cai L, Liu SJ. Diversity, Distribution and Co-occurrence Patterns of Bacterial Communities in a Karst Cave System. Front Microbiol 2019; 10:1726. [PMID: 31447801 PMCID: PMC6691740 DOI: 10.3389/fmicb.2019.01726] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2019] [Accepted: 07/12/2019] [Indexed: 12/21/2022] Open
Abstract
Caves are typified by their permanent darkness and a shortage of nutrients. Consequently, bacteria play an important role in sustaining such subsurface ecosystems by dominating primary production and fueling biogeochemical cycles. China has one of the world’s largest areas of karst topography in the Yunnan-Guizhou Plateau, yet the bacteriomes in these karst caves remain unexplored. In this study, bacteriomes of eight karst caves in southwest China were examined, and co-occurrence networks of cave bacterial communities were constructed. Results revealed abundant and diversified bacterial communities in karst caves, with Proteobacteria, Actinobacteria, and Firmicutes being the most abundant phyla. Statistical analysis revealed no significant difference in bacteriomes among the eight caves. However, a PCoA plot did show that the bacterial communities of 128 cave samples clustered into groups corresponding to sampling types (air, water, rock, and sediment). These results suggest that the distribution of bacterial communities is driven more by sample types than the separate caves from which samples were collected. Further community-level composition analysis indicated that Proteobacteria were most dominant in water and air samples, while Actinobacteria dominated the sediment and rock samples. Co-occurrence analysis revealed highly modularized assembly patterns of the cave bacterial community, with Nitrosococcaceae wb1-P19, an uncultured group in Rokubacteriales, and an uncultured group in Gaiellales, being the top-three keystone members. These results not only expand our understanding of cave bacteriomes but also inspires functional exploration of bacterial strains in karst caves.
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Affiliation(s)
- Hai-Zhen Zhu
- State Key Laboratory of Microbial Resources and Environmental Microbiology Research Center at Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Zhi-Feng Zhang
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China.,State Key Laboratory of Mycology at Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Nan Zhou
- State Key Laboratory of Microbial Resources and Environmental Microbiology Research Center at Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Cheng-Ying Jiang
- State Key Laboratory of Microbial Resources and Environmental Microbiology Research Center at Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.,Research Center for Eco-Envorinmental Sciences-Institute of Microbiology, Chinese Academy of Sciences-University of Chinese Academy of Sciences, Joint-Lab of Microbial Technology for Environmental Science, Beijing, China
| | - Bao-Jun Wang
- State Key Laboratory of Microbial Resources and Environmental Microbiology Research Center at Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Lei Cai
- State Key Laboratory of Mycology at Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Shuang-Jiang Liu
- State Key Laboratory of Microbial Resources and Environmental Microbiology Research Center at Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China.,Research Center for Eco-Envorinmental Sciences-Institute of Microbiology, Chinese Academy of Sciences-University of Chinese Academy of Sciences, Joint-Lab of Microbial Technology for Environmental Science, Beijing, China.,College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, China
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23
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Zhao R, Wang H, Cheng X, Yun Y, Qiu X. Upland soil cluster γ dominates the methanotroph communities in the karst Heshang Cave. FEMS Microbiol Ecol 2019; 94:5107866. [PMID: 30265314 DOI: 10.1093/femsec/fiy192] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Accepted: 09/26/2018] [Indexed: 11/13/2022] Open
Abstract
Microorganisms are thought to play a critical role in methane (CH4) consumption in karst caves and yet the presence and diversity of methane-oxidizing bacteria (MOB) remain a mystery. In Heshang Cave, CH4 concentration decreases from 1.9 ppm at the entrance to 0.65 ppm inside the cave. To explore the presence and diversity of MOB in this cave, weathered rocks and sediment samples were collected from the cave and subjected to molecular analysis. The abundances of MOB were 107-108 copies g-1 dry sample via quantification of the pmoA gene, which are comparable to or even higher than those reported in other terrestrial environments, and account for up to 20% of the total microbial communities. Phylogenetically, MOB communities were dominated by the 'high-affinity' upland soil cluster γ (USCγ), although the predominance of Type Ia MOB was also detected in the permanently waterlogged stream sediment. The estimated CH4 oxidation potential varied dramatically among samples in the range of 0.6-80 CH4 m-3 d-1. Collectively, this study provides compelling evidence that the high-affinity MOB capable of oxidizing CH4 at the atmospheric level are present in Heshang Cave, which may play an important role in the CH4 consumption, and supports karst caves as important atmospheric CH4 sinks.
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Affiliation(s)
- Rui Zhao
- State Key Laboratory of Biogeology and Environment Geology, China University of Geosciences, Wuhan 430074, P. R. China.,Now at School of Marine Science and Policy, University of Delaware, Lewes 19958, Delaware, USA
| | - Hongmei Wang
- State Key Laboratory of Biogeology and Environment Geology, China University of Geosciences, Wuhan 430074, P. R. China.,Laboratory of Basin Hydrology and Wetland Eco-restoration, China University of Geosciences, Wuhan, 430074, P. R. China
| | - Xiaoyu Cheng
- State Key Laboratory of Biogeology and Environment Geology, China University of Geosciences, Wuhan 430074, P. R. China
| | - Yuan Yun
- State Key Laboratory of Biogeology and Environment Geology, China University of Geosciences, Wuhan 430074, P. R. China
| | - Xuan Qiu
- State Key Laboratory of Biogeology and Environment Geology, China University of Geosciences, Wuhan 430074, P. R. China
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Wiseschart A, Mhuantong W, Tangphatsornruang S, Chantasingh D, Pootanakit K. Shotgun metagenomic sequencing from Manao-Pee cave, Thailand, reveals insight into the microbial community structure and its metabolic potential. BMC Microbiol 2019; 19:144. [PMID: 31248378 PMCID: PMC6598295 DOI: 10.1186/s12866-019-1521-8] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Accepted: 06/19/2019] [Indexed: 12/21/2022] Open
Abstract
Background Due to the cave oligotrophic environment, this habitat presents a challenge for microorganisms to colonize and thrive. However, it has been well documented that microorganisms play important roles in cave development. Survival of microbes in this unique habitat likely involves a broad range of adaptive capabilities. Recently, cave microbiomes all over the world are of great scientific interest. However, the majority of investigations focused mostly on small subunit ribosomal RNA (16S rRNA) gene, leaving the ecological role of the microbial community largely unknown. Here, we are particularly interested in exploring the taxonomic composition and metabolic potential of microorganisms in soil from Manao-Pee cave, a subterranean limestone cave in the western part of Thailand, by using high-throughput shotgun metagenomic sequencing. Results From taxonomic composition analysis using ribosomal RNA genes (rRNA), the results confirmed that Actinobacteria (51.2%) and Gammaproteobacteria (24.4%) were the dominant bacterial groups in the cave soil community. Metabolic potential analysis, based on six functional modules of the Kyoto Encyclopedia of Genes and Genomes (KEGG) database, revealed that functional genes involved in microbial metabolisms are highly represented in this community (40.6%). To better understand how microbes thrive under unfavorable cave condition, we focused on microbial energy metabolism. The results showed that microbial genes involved in oxidative phosphorylation were the most dominant (28.8%) in Manao-Pee cave, and were followed by methane metabolism (20.5%), carbon fixation (16.0%), nitrogen metabolism (14.7%), and sulfur metabolism (6.3%). In addition, microbial genes involved in xenobiotic biodegradation (26 pathways) and in production of secondary metabolites (27 pathways) were also identified. Conclusion In addition to providing information on microbial diversity, we also gained insights into microbial adaptations and survival strategies under cave conditions. Based on rRNA genes, the results revealed that bacteria belonging to the Actinobacteria and Gammaproteobacteria were the most abundant in this community. From metabolic potential analysis, energy and nutrient sources that sustain diverse microbial population in this community might be atmospheric gases (methane, carbon dioxide, nitrogen), inorganic sulfur, and xenobiotic compounds. In addition, the presence of biosynthetic pathways of secondary metabolites suggested that they might play important ecological roles in the cave microbiome. Electronic supplementary material The online version of this article (10.1186/s12866-019-1521-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Apirak Wiseschart
- Institute of Molecular Biosciences, Mahidol University, Salaya Campus, Phuttamonthon 4 Rd, Salaya, Nakhon Pathom, 73170, Thailand
| | - Wuttichai Mhuantong
- National Center for Genetic Engineering and Biotechnology (BIOTEC), 133 Thailand Science Park, Paholyothin Rd, Klong 1, Klongluang, Pathumthani, 12120, Thailand
| | - Sithichoke Tangphatsornruang
- National Center for Genetic Engineering and Biotechnology (BIOTEC), 133 Thailand Science Park, Paholyothin Rd, Klong 1, Klongluang, Pathumthani, 12120, Thailand
| | - Duriya Chantasingh
- National Center for Genetic Engineering and Biotechnology (BIOTEC), 133 Thailand Science Park, Paholyothin Rd, Klong 1, Klongluang, Pathumthani, 12120, Thailand
| | - Kusol Pootanakit
- Institute of Molecular Biosciences, Mahidol University, Salaya Campus, Phuttamonthon 4 Rd, Salaya, Nakhon Pathom, 73170, Thailand.
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Kimble JC, Winter AS, Spilde MN, Sinsabaugh RL, Northup DE. A potential central role of Thaumarchaeota in N-Cycling in a semi-arid environment, Fort Stanton Cave, Snowy River passage, New Mexico, USA. FEMS Microbiol Ecol 2018; 94:5079639. [PMID: 30165514 PMCID: PMC6669814 DOI: 10.1093/femsec/fiy173] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Accepted: 08/23/2018] [Indexed: 01/03/2023] Open
Abstract
Low biomass and productivity of arid-land caves with limited availability of nitrogen (N) raises the question of how microbes acquire and cycle this essential element. Caves are ideal environments for investigating microbial functional capabilities, as they lack phototrophic activity and have near constant temperatures and high relative humidity. From the walls of Fort Stanton Cave (FSC), multicolored secondary mineral deposits of soil-like material low in fixed N, known as ferromanganese deposits (FMD), were collected. We hypothesized that within FMD samples we would find the presence of microbial N cycling genes and taxonomy related to N cycling microorganisms. Community DNA were sequenced using Illumina shotgun metagenomics and 16S rRNA gene sequencing. Results suggest a diverse N cycle encompassing several energetic pathways including nitrification, dissimilatory nitrate reduction and denitrification. N cycling genes associated with assimilatory nitrate reduction were also identified. Functional gene sequences and taxonomic findings suggest several bacterial and archaeal phyla potentially play a role in nitrification pathways in FSC and FMD. Thaumarchaeota, a deep-branching archaeal division, likely play an essential and possibly dominant role in the oxidation of ammonia. Our results provide genomic evidence for understanding how microbes are potentially able to acquire and cycle N in a low-nutrient subterranean environment.
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Affiliation(s)
- Jason C Kimble
- Department of Biology, MSC03-2020, University of New Mexico, Albuquerque, NM 87131, USA
| | - Ara S Winter
- Department of Biology, MSC03-2020, University of New Mexico, Albuquerque, NM 87131, USA
| | - Michael N Spilde
- Institute of Meteoritics, MSC03-2050, University of New Mexico, Albuquerque, NM 87131, USA
| | - Robert L Sinsabaugh
- Department of Biology, MSC03-2020, University of New Mexico, Albuquerque, NM 87131, USA
| | - Diana E Northup
- Department of Biology, MSC03-2020, University of New Mexico, Albuquerque, NM 87131, USA
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High-Throughput Sequencing Analysis of the Actinobacterial Spatial Diversity in Moonmilk Deposits. Antibiotics (Basel) 2018; 7:antibiotics7020027. [PMID: 29561792 PMCID: PMC6023079 DOI: 10.3390/antibiotics7020027] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Revised: 03/15/2018] [Accepted: 03/16/2018] [Indexed: 11/16/2022] Open
Abstract
Moonmilk are cave carbonate deposits that host a rich microbiome, including antibiotic-producing Actinobacteria, making these speleothems appealing for bioprospecting. Here, we investigated the taxonomic profile of the actinobacterial community of three moonmilk deposits of the cave "Grotte des Collemboles" via high-throughput sequencing of 16S rRNA amplicons. Actinobacteria was the most common phylum after Proteobacteria, ranging from 9% to 23% of the total bacterial population. Next to actinobacterial operational taxonomic units (OTUs) attributed to uncultured organisms at the genus level (~44%), we identified 47 actinobacterial genera with Rhodoccocus (4 OTUs, 17%) and Pseudonocardia (9 OTUs, ~16%) as the most abundant in terms of the absolute number of sequences. Streptomycetes presented the highest diversity (19 OTUs, 3%), with most of the OTUs unlinked to the culturable Streptomyces strains that were previously isolated from the same deposits. Furthermore, 43% of the OTUs were shared between the three studied collection points, while 34% were exclusive to one deposit, indicating that distinct speleothems host their own population, despite their nearby localization. This important spatial diversity suggests that prospecting within different moonmilk deposits should result in the isolation of unique and novel Actinobacteria. These speleothems also host a wide range of non-streptomycetes antibiotic-producing genera, and should therefore be subjected to methodologies for isolating rare Actinobacteria.
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In Situ Cultured Bacterial Diversity from Iron Curtain Cave, Chilliwack, British Columbia, Canada. DIVERSITY 2017. [DOI: 10.3390/d9030036] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Leuko S, Koskinen K, Sanna L, D’Angeli IM, De Waele J, Marcia P, Moissl-Eichinger C, Rettberg P. The influence of human exploration on the microbial community structure and ammonia oxidizing potential of the Su Bentu limestone cave in Sardinia, Italy. PLoS One 2017; 12:e0180700. [PMID: 28704427 PMCID: PMC5507542 DOI: 10.1371/journal.pone.0180700] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Accepted: 06/20/2017] [Indexed: 01/20/2023] Open
Abstract
The bacterial diversity in the Su Bentu Cave in Sardinia was investigated by means of 16S rRNA gene-based analysis. This 15 km long cave, carved in Jurassic limestone, hosts a variety of calcite speleothems, and a long succession of subterranean lakes with mixed granite and carbonate sands. The lower level is occasionally flooded by a rising groundwater level, but with only scarce input of organic remains (leaves and charcoal fragments). On the quiet cave pools there are visible calcite rafts, whereas walls are locally coated with manganese deposits. In the drier upper levels, where organic input is much more subdued, moonmilk—a hydrated calcium-magnesium carbonate speleothem—can be found. Relative humidity approaches 100% and the measured mean annual cave air temperature is 14.8°C. Samples were obtained in 2014 from calcite rafts, moonmilk, manganese oxide deposits and soil (limestone and granite grains). Microclimatic conditions in the cave near the sampling sites, sample properties, physico-chemical parameters of water, and sediment composition were determined. The microbial community of this system is predominately composed of the phyla Proteobacteria, Actinobacteria, Acidobacteria, Nitrospirae, and Firmicutes. Sampling sites near the entrance of the cave and in close proximity of the underground campsite–located 500 meters deep into the cave—revealed the highest diversity as well as the highest number of human associated microorganisms. Two samples obtained in very close proximity of each other near the campsite, indicate that the human impact is localized and is not distributed freely within the system. Analysis of the abundance of bacterial and archaeal amoA genes revealed a far greater abundance of archaeal amoA genes compared to bacterial representatives. The results of this study highlight that human impact is confined to locations that are utilized as campsites and that exploration leaves little microbial trails. Furthermore, we uncovered a highly specialized microbiome, which is perfectly adapted to survive and thrive in an environment with low nutrient availability.
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Affiliation(s)
- Stefan Leuko
- German Aerospace Center (DLR e.V.), Institute of Aerospace Medicine, Radiation Biology Department, Research Group 'Astrobiology', Linder Höhe, Cologne (Köln), Germany
- * E-mail:
| | - Kaisa Koskinen
- Medical University of Graz, Section of Infectious Diseases and Tropical Medicine, Department of Internal Medicine, BioTechMed, Krenngasse, Graz, Austria
| | - Laura Sanna
- Institute for Biometeorology, National Research Council of Italy, Sassari, Italy
| | | | - Jo De Waele
- Italian Institute of Speleology, University of Bologna, Bologna, Italy
| | - Paolo Marcia
- Dipartimento di Scienze della Natura e del Territorio, Università di Sassari, Sassari, Italy
| | - Christine Moissl-Eichinger
- Medical University of Graz, Section of Infectious Diseases and Tropical Medicine, Department of Internal Medicine, BioTechMed, Krenngasse, Graz, Austria
| | - Petra Rettberg
- German Aerospace Center (DLR e.V.), Institute of Aerospace Medicine, Radiation Biology Department, Research Group 'Astrobiology', Linder Höhe, Cologne (Köln), Germany
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De Mandal S, Chatterjee R, Kumar NS. Dominant bacterial phyla in caves and their predicted functional roles in C and N cycle. BMC Microbiol 2017; 17:90. [PMID: 28399822 PMCID: PMC5387202 DOI: 10.1186/s12866-017-1002-x] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Accepted: 04/06/2017] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND Bacteria present in cave often survive by modifying their metabolic pathway or other mechanism. Understanding these adopted bacteria and their survival strategy inside the cave is an important aspect of microbial ecology. Present study focuses on the bacterial community and geochemistry in five caves of Mizoram, Northeast India. The objective of this study was to explore the taxonomic composition and presumed functional diversity of cave sediment metagenomes using paired end Illumina sequencing using V3 region of 16S rRNA gene and bioinformatics pipeline. RESULTS Actinobacteria, Proteobacteria, Verrucomicrobia and Acidobacteria were the major phyla in all the five cave sediment samples. Among the five caves the highest diversity is found in Lamsialpuk with a Shannon index 12.5 and the lowest in Bukpuk (Shannon index 8.22). In addition, imputed metagenomic approach was used to predict the functional role of microbial community in biogeochemical cycling in the cave environments. Functional module showed high representation of genes involved in Amino Acid Metabolism in (20.9%) and Carbohydrate Metabolism (20.4%) in the KEGG pathways. Genes responsible for carbon degradation, carbon fixation, methane metabolism, nitrification, nitrate reduction and ammonia assimilation were also predicted in the present study. CONCLUSION The cave sediments of the biodiversity hotspot region possessing a oligotrophic environment harbours high phylogenetic diversity dominated by Actinobacteria and Proteobacteria. Among the geochemical factors, ferric oxide was correlated with increased microbial diversity. In-silico analysis detected genes involved in carbon, nitrogen, methane metabolism and complex metabolic pathways responsible for the survival of the bacterial community in nutrient limited cave environments. Present study with Paired end Illumina sequencing along with bioinformatics analysis revealed the essential ecological role of the cave bacterial communities. These results will be useful in documenting the biospeleology of this region and systematic understanding of bacterial communities in natural sediment environments as well.
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Affiliation(s)
- Surajit De Mandal
- Department of Biotechnology, Mizoram University, Aizawl, Mizoram, 796004, India
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Lennon JT, Nguyễn-Thùy D, Phạm TM, Drobniak A, Tạ PH, Phạm NÐ, Streil T, Webster KD, Schimmelmann A. Microbial contributions to subterranean methane sinks. GEOBIOLOGY 2017; 15:254-258. [PMID: 27671735 DOI: 10.1111/gbi.12214] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Accepted: 08/25/2016] [Indexed: 06/06/2023]
Abstract
Sources and sinks of methane (CH4 ) are critical for understanding global biogeochemical cycles and their role in climate change. A growing number of studies have reported that CH4 concentrations in cave ecosystems are depleted, leading to the notion that these subterranean environments may act as sinks for atmospheric CH4 . Recently, it was hypothesized that this CH4 depletion may be caused by radiolysis, an abiotic process whereby CH4 is oxidized via interactions with ionizing radiation derived from radioactive decay. An alternate explanation is that the depletion of CH4 concentrations in caves could be due to biological processes, specifically oxidation by methanotrophic bacteria. We theoretically explored the radiolysis hypothesis and conclude that it is a kinetically constrained process that is unlikely to lead to the rapid loss of CH4 in subterranean environments. We present results from a controlled laboratory experiment to support this claim. We then tested the microbial oxidation hypothesis with a set of mesocosm experiments that were conducted in two Vietnamese caves. Our results reveal that methanotrophic bacteria associated with cave rocks consume CH4 at a rate of 1.3-2.7 mg CH4 · m-2 · d-1 . These CH4 oxidation rates equal or exceed what has been reported in other habitats, including agricultural systems, grasslands, deciduous forests, and Arctic tundra. Together, our results suggest that depleted concentrations of CH4 in caves are most likely due to microbial activity, not radiolysis as has been recently claimed. Microbial methanotrophy has the potential to oxidize CH4 not only in caves, but also in smaller-size open subterranean spaces, such as cracks, fissures, and other pores that are connected to and rapidly exchange with the atmosphere. Future studies are needed to understand how subterranean CH4 oxidation scales up to affect local, regional, and global CH4 cycling.
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Affiliation(s)
- J T Lennon
- Department of Biology, Indiana University, Bloomington, IN, USA
| | - D Nguyễn-Thùy
- Faculty of Geology, Vietnam National University, Hanoi, Vietnam
| | - T M Phạm
- Department of Microbiology, Vietnam National University, Hanoi, Vietnam
| | - A Drobniak
- Indiana Geological Survey, Indiana University, Bloomington, IN, USA
| | - P H Tạ
- Faculty of Geology, Vietnam National University, Hanoi, Vietnam
| | - N Ð Phạm
- Department of Microbiology, Vietnam National University, Hanoi, Vietnam
| | | | - K D Webster
- Department of Geological Sciences, Indiana University, Bloomington, IN, USA
| | - A Schimmelmann
- Department of Geological Sciences, Indiana University, Bloomington, IN, USA
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Lavoie KH, Winter AS, Read KJH, Hughes EM, Spilde MN, Northup DE. Comparison of bacterial communities from lava cave microbial mats to overlying surface soils from Lava Beds National Monument, USA. PLoS One 2017; 12:e0169339. [PMID: 28199330 PMCID: PMC5310854 DOI: 10.1371/journal.pone.0169339] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2016] [Accepted: 12/15/2016] [Indexed: 11/26/2022] Open
Abstract
Subsurface habitats harbor novel diversity that has received little attention until recently. Accessible subsurface habitats include lava caves around the world that often support extensive microbial mats on ceilings and walls in a range of colors. Little is known about lava cave microbial diversity and how these subsurface mats differ from microbial communities in overlying surface soils. To investigate these differences, we analyzed bacterial 16S rDNA from 454 pyrosequencing from three colors of microbial mats (tan, white, and yellow) from seven lava caves in Lava Beds National Monument, CA, USA, and compared them with surface soil overlying each cave. The same phyla were represented in both surface soils and cave microbial mats, but the overlap in shared OTUs (operational taxonomic unit) was only 11.2%. Number of entrances per cave and temperature contributed to observed differences in diversity. In terms of species richness, diversity by mat color differed, but not significantly. Actinobacteria dominated in all cave samples, with 39% from caves and 21% from surface soils. Proteobacteria made up 30% of phyla from caves and 36% from surface soil. Other major phyla in caves were Nitrospirae (7%) followed by minor phyla (7%), compared to surface soils with Bacteroidetes (8%) and minor phyla (8%). Many of the most abundant sequences could not be identified to genus, indicating a high degree of novelty. Surface soil samples had more OTUs and greater diversity indices than cave samples. Although surface soil microbes immigrate into underlying caves, the environment selects for microbes able to live in the cave habitats, resulting in very different cave microbial communities. This study is the first comprehensive comparison of bacterial communities in lava caves with the overlying soil community.
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Affiliation(s)
- Kathleen H Lavoie
- Biology, State University of New York, College at Plattsburgh, Plattsburgh, NY, United States of America
| | - Ara S Winter
- Biology, University of New Mexico, Albuquerque, NM, United States of America
| | - Kaitlyn J H Read
- Biology, University of New Mexico, Albuquerque, NM, United States of America
| | - Evan M Hughes
- Biology, University of New Mexico, Albuquerque, NM, United States of America
| | - Michael N Spilde
- Institute of Meteoritics, University of New Mexico, Albuquerque, NM, United States of America
| | - Diana E Northup
- Biology, University of New Mexico, Albuquerque, NM, United States of America
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Huang Z, Zhao F, Li Y, Zhang J, Feng Y. Variations in the bacterial community compositions at different sites in the tomb of Emperor Yang of the Sui Dynasty. Microbiol Res 2016; 196:26-33. [PMID: 28164788 DOI: 10.1016/j.micres.2016.12.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2016] [Revised: 11/29/2016] [Accepted: 12/07/2016] [Indexed: 11/28/2022]
Abstract
To fully understand the bacterial processes in tomb environments, it is necessary to investigate the details of the bacterial communities present under such oligotrophic conditions. Here, high-throughput sequencing based on partial 16S rRNA gene sequences was used to fully evaluate the bacterial communities at different sites in the tomb of Emperor Yang of the Sui Dynasty. We also aimed to identify the soil factors that were significant related to bacterial diversity and community composition. The results showed the presence of a broad taxonomic diversity that included nine major phyla. Actinobacteria, Firmicutes and Proteobacteria dominated the bacterial profiles in all tomb soil samples. However, significant differences between deposited soils (DS) and covering soils (CSA, CSB and CSC) were revealed by chemistry-based principal component analysis (PCA), the number of OTUs, and the Chao 1 and Shannon indexes. At the family level, hierarchically clustered heatmap and LefSe analyses showed differences in the bacterial community compositions at different sampling sites. Notably, CSA contained significant populations of Nocardioidaceae, Pseudonocardiaceae and Streptomycetaceae, which are often reported to be associated with biodeterioration in cave environments. Further, the most abundant group (>10%) in all soil samples was Streptococcaceae, whose abundance decreased from 34.66% to 13.43% with increasing soil depth. The results of redundancy analysis (RDA) and the Monte Carlo permutation test indicated that soil pH and Cu and Mn levels were significantly related to the bacterial communities in this tomb. This research offers new insight into bacterial communities in cave environments and also provides important information for the protection of this historically important tomb.
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Affiliation(s)
- Zhi Huang
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China.
| | - Fei Zhao
- Nanjing Institute for Comprehensive utilization of Wild Plants, China CO-OP, Nanjing 210042, China
| | - Yonghui Li
- Key Laboratory of Urban and Architectural Heritage Conservation of Ministry of Education, School of Architecture, Southeast University, Nanjing 210096, China
| | - Jianwei Zhang
- State Key Laboratory Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China
| | - Youzhi Feng
- State Key Laboratory Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China.
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Okyay TO, Nguyen HN, Castro SL, Rodrigues DF. CO 2 sequestration by ureolytic microbial consortia through microbially-induced calcite precipitation. THE SCIENCE OF THE TOTAL ENVIRONMENT 2016; 572:671-680. [PMID: 27524723 DOI: 10.1016/j.scitotenv.2016.06.199] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Revised: 06/25/2016] [Accepted: 06/25/2016] [Indexed: 06/06/2023]
Abstract
Urea is an abundant nitrogen-containing compound found in urine of mammals and widely used in fertilizers. This compound is part of the nitrogen biogeochemical cycle and is easily biodegraded by ureolytic microorganisms that have the urease enzyme. Previous studies, with ureolytic isolates, have shown that some ureolytic microorganisms are able to sequester CO2 through a process called microbially-induced calcium carbonate precipitation. The present study investigates 15 ureolytic consortia obtained from the "Pamukkale travertines" and the "Cave Without A Name" using different growth media to identify the possible bacterial genera responsible for CO2 sequestration through the microbially-induced calcite precipitation (MICP). The community structure and diversity were determined by deep-sequencing. The results showed that all consortia presented varying CO2 sequestration capabilities and MICP rates. The CO2 sequestration varied between 0 and 86.4%, and it depended largely on the community structure, as well as on pH. Consortia with predominance of Comamonas, Plesiomonas and Oxalobacter presented reduced CO2 sequestration. On the other hand, consortia dominated by Sporosarcina, Sphingobacterium, Stenotrophomonas, Acinetobacter, and Elizabethkingia showed higher rates of CO2 uptake in the serum bottle headspace.
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Affiliation(s)
- Tugba O Okyay
- Department of Civil and Environmental Engineering, University of Houston, Houston, TX 77204-4003, USA
| | - Hang N Nguyen
- Department of Civil and Environmental Engineering, University of Houston, Houston, TX 77204-4003, USA
| | - Sarah L Castro
- NASA Johnson Space Center Microbiology Laboratory, Houston, TX 77058, USA
| | - Debora F Rodrigues
- Department of Civil and Environmental Engineering, University of Houston, Houston, TX 77204-4003, USA.
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Ghosh S, Kuisiene N, Cheeptham N. The cave microbiome as a source for drug discovery: Reality or pipe dream? Biochem Pharmacol 2016; 134:18-34. [PMID: 27867014 DOI: 10.1016/j.bcp.2016.11.018] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Accepted: 11/15/2016] [Indexed: 01/04/2023]
Abstract
This review highlights cave habitats, cave microbiomes and their potential for drug discovery. Such studies face many challenges, including access to remote and pristine caves, and sample collection and transport. Inappropriate physical and chemical growth conditions in the laboratory for the isolation and cultivation of cave microorganisms pose many complications including length of cultivation; some cave microorganisms can take weeks and even months to grow. Additionally, DNA extraction from cave environmental samples may be difficult due to the high concentration of various minerals that are natural DNA blocking agents. Once cave microorganisms are grown in the lab, other problems often arise, such as maintenance of pure culture, consistency of antimicrobial activity and fermentation conditions for antimicrobial production. In this review, we suggest that, although based on what has been done in the field, there is potential in using cave microorganisms to produce antimicrobial agents, one needs to be highly committed and prepared.
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Affiliation(s)
- Soumya Ghosh
- Department of Biological Sciences, Faculty of Science, Thompson Rivers University, Kamloops, BC, Canada
| | - Nomeda Kuisiene
- Department of Microbiology and Biotechnology, Vilnius University, Lithuania
| | - Naowarat Cheeptham
- Department of Biological Sciences, Faculty of Science, Thompson Rivers University, Kamloops, BC, Canada.
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Gulecal-Pektas Y. Bacterial Diversity and Composition in Oylat Cave (Turkey) with Combined Sanger/Pyrosequencing Approach. Pol J Microbiol 2016; 65:69-75. [PMID: 27281996 DOI: 10.5604/17331331.1197277] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The microbiology of caves is an important topic for better understanding subsurface biosphere diversity. The diversity and taxonomic composition of bacterial communities associated with cave walls of the Oylat Cave was studied first time by molecular cloning based on Sanger/pyrosequencing approach. Results showed an average of 1,822 operational taxonomic units per sample. Clones analyzed from Oylat Cave were found to belong to 10 common phyla within the domain Bacteria. Proteobacteria dominated the phyla, followed by Actinobacteria, Acidobacteria and Nitrospirae. Shannon diversity index was between to 3.76 and 5.35. The robust analysis conducted for this study demonstrated high bacterial diversity on cave rock wall surfaces.
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De Mandal S, Panda AK, Bisht SS, Senthil Kumar N. MiSeq HV4 16S rRNA gene analysis of bacterial community composition among the cave sediments of Indo-Burma biodiversity hotspot. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2016; 23:12216-12226. [PMID: 26971799 DOI: 10.1007/s11356-016-6423-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Accepted: 03/03/2016] [Indexed: 06/05/2023]
Abstract
Caves in Mizoram, Northeast India, are potential hotspot diversity regions due to the historical significance of the formation of the Indo-Burman plateau and also because of their unexplored and unknown diversity. High-throughput paired end Illumina sequencing of the V4 region of 16S rRNA was performed to study the bacterial community of three caves situated in Champhai district of Mizoram, Northeast India. A total of 10,643 operational taxonomic units (OTUs) (based on 97 % cutoff) comprising of 21 major and 21 candidate phyla with a sequencing depth of 1,140,013 were found in this study. The overall taxonomic profile obtained by the RDP classifier and Greengenes OTU database revealed high diversity within the bacterial communities. Communities were dominated by Planctomycetes, Actinobacteria, Proteobacteria, Bacteroidetes, and Firmicutes, while members of Archaea were less varied and mostly comprising of Eukaryoarchea. Analysis revealed that Farpuk (CFP) cave sediment has low microbial diversity and is mainly dominated by Actinobacteria (80 % reads), whereas different bacterial communities were found in the caves of Murapuk (CMP) and Lamsialpuk (CLP). Analysis also revealed that a major portion of the identified OTUs was classified under rare biosphere. Importantly, all these caves recorded a high number of unclassified OTUs, which might represent new species. Further analysis with whole genome sequencing is needed to validate the unknown species as well as to determine their functional role.
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Affiliation(s)
- Surajit De Mandal
- Department of Biotechnology, Mizoram University, Aizawl, 796004, Mizoram, India
| | - Amrita Kumari Panda
- Department of Zoology, Kumaun University, Nainital, 263002, Uttarakhand, India
| | - Satpal Singh Bisht
- Department of Zoology, Kumaun University, Nainital, 263002, Uttarakhand, India
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Zepeda Mendoza ML, Lundberg J, Ivarsson M, Campos P, Nylander JAA, Sallstedt T, Dalen L. Metagenomic Analysis from the Interior of a Speleothem in Tjuv-Ante's Cave, Northern Sweden. PLoS One 2016; 11:e0151577. [PMID: 26985997 PMCID: PMC4795671 DOI: 10.1371/journal.pone.0151577] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2015] [Accepted: 03/01/2016] [Indexed: 02/01/2023] Open
Abstract
Speleothems are secondary mineral deposits normally formed by water supersaturated with calcium carbonate percolating into underground caves, and are often associated with low-nutrient and mostly non-phototrophic conditions. Tjuv-Ante's cave is a shallow-depth cave formed by the action of waves, with granite and dolerite as major components, and opal-A and calcite as part of the speleothems, making it a rare kind of cave. We generated two DNA shotgun sequencing metagenomic datasets from the interior of a speleothem from Tjuv-Ante's cave representing areas of old and relatively recent speleothem formation. We used these datasets to perform i) an evaluation of the use of these speleothems as past biodiversity archives, ii) functional and taxonomic profiling of the speleothem's different formation periods, and iii) taxonomic comparison of the metagenomic results to previous microscopic analyses from a nearby speleothem of the same cave. Our analyses confirm the abundance of Actinobacteria and fungi as previously reported by microscopic analyses on this cave, however we also discovered a larger biodiversity. Interestingly, we identified photosynthetic genes, as well as genes related to iron and sulphur metabolism, suggesting the presence of chemoautotrophs. Furthermore, we identified taxa and functions related to biomineralization. However, we could not confidently establish the use of this type of speleothems as biological paleoarchives due to the potential leaching from the outside of the cave and the DNA damage that we propose has been caused by the fungal chemical etching.
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Affiliation(s)
| | - Johannes Lundberg
- Department of Botany, Swedish Museum of Natural History, Stockholm, Sweden
| | - Magnus Ivarsson
- Department of Palaeobiology and the Nordic Center for Earth Evolution (NordCEE), Swedish Museum of Natural History, Stockholm, Sweden
| | - Paula Campos
- Centre for GeoGenetics, University of Copenhagen, Natural History Museum of Denmark, Copenhagen, Denmark
| | - Johan A. A. Nylander
- Department of Bioinformatics and Genetics, Swedish Museum of Natural History, Stockholm, Sweden
| | - Therese Sallstedt
- Department of Palaeobiology and the Nordic Center for Earth Evolution (NordCEE), Swedish Museum of Natural History, Stockholm, Sweden
| | - Love Dalen
- Department of Bioinformatics and Genetics, Swedish Museum of Natural History, Stockholm, Sweden
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Zhu T, Dittrich M. Carbonate Precipitation through Microbial Activities in Natural Environment, and Their Potential in Biotechnology: A Review. Front Bioeng Biotechnol 2016; 4:4. [PMID: 26835451 PMCID: PMC4718973 DOI: 10.3389/fbioe.2016.00004] [Citation(s) in RCA: 173] [Impact Index Per Article: 21.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Accepted: 01/07/2016] [Indexed: 11/24/2022] Open
Abstract
Calcium carbonate represents a large portion of carbon reservoir and is used commercially for a variety of applications. Microbial carbonate precipitation, a by-product of microbial activities, plays an important metal coprecipitation and cementation role in natural systems. This natural process occurring in various geological settings can be mimicked and used for a number of biotechnologies, such as metal remediation, carbon sequestration, enhanced oil recovery, and construction restoration. In this study, different metabolic activities leading to calcium carbonate precipitation, their native environment, and potential applications and challenges are reviewed.
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Affiliation(s)
- Tingting Zhu
- Department of Physical and Environmental Sciences, University of Toronto Scarborough , Toronto, ON , Canada
| | - Maria Dittrich
- Department of Physical and Environmental Sciences, University of Toronto Scarborough , Toronto, ON , Canada
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Kieraite-Aleksandrova I, Aleksandrovas V, Kuisiene N. Down into the Earth: microbial diversity of the deepest cave of the world. Biologia (Bratisl) 2015. [DOI: 10.1515/biolog-2015-0127] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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Riquelme C, Marshall Hathaway JJ, Enes Dapkevicius MDLN, Miller AZ, Kooser A, Northup DE, Jurado V, Fernandez O, Saiz-Jimenez C, Cheeptham N. Actinobacterial Diversity in Volcanic Caves and Associated Geomicrobiological Interactions. Front Microbiol 2015; 6:1342. [PMID: 26696966 PMCID: PMC4673402 DOI: 10.3389/fmicb.2015.01342] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Accepted: 11/16/2015] [Indexed: 11/23/2022] Open
Abstract
Volcanic caves are filled with colorful microbial mats on the walls and ceilings. These volcanic caves are found worldwide, and studies are finding vast bacteria diversity within these caves. One group of bacteria that can be abundant in volcanic caves, as well as other caves, is Actinobacteria. As Actinobacteria are valued for their ability to produce a variety of secondary metabolites, rare and novel Actinobacteria are being sought in underexplored environments. The abundance of novel Actinobacteria in volcanic caves makes this environment an excellent location to study these bacteria. Scanning electron microscopy (SEM) from several volcanic caves worldwide revealed diversity in the morphologies present. Spores, coccoid, and filamentous cells, many with hair-like or knobby extensions, were some of the microbial structures observed within the microbial mat samples. In addition, the SEM study pointed out that these features figure prominently in both constructive and destructive mineral processes. To further investigate this diversity, we conducted both Sanger sequencing and 454 pyrosequencing of the Actinobacteria in volcanic caves from four locations, two islands in the Azores, Portugal, and Hawai'i and New Mexico, USA. This comparison represents one of the largest sequencing efforts of Actinobacteria in volcanic caves to date. The diversity was shown to be dominated by Actinomycetales, but also included several newly described orders, such as Euzebyales, and Gaiellales. Sixty-two percent of the clones from the four locations shared less than 97% similarity to known sequences, and nearly 71% of the clones were singletons, supporting the commonly held belief that volcanic caves are an untapped resource for novel and rare Actinobacteria. The amplicon libraries depicted a wider view of the microbial diversity in Azorean volcanic caves revealing three additional orders, Rubrobacterales, Solirubrobacterales, and Coriobacteriales. Studies of microbial ecology in volcanic caves are still very limited. To rectify this deficiency, the results from our study help fill in the gaps in our knowledge of actinobacterial diversity and their potential roles in the volcanic cave ecosystems.
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Affiliation(s)
- Cristina Riquelme
- Food Science and Health Group (CITA-A), Departamento de Ciências Agrárias, Universidade dos Açores Angra do Heroísmo, Portugal
| | | | - Maria de L N Enes Dapkevicius
- Food Science and Health Group (CITA-A), Departamento de Ciências Agrárias, Universidade dos Açores Angra do Heroísmo, Portugal
| | - Ana Z Miller
- Instituto de Recursos Naturales y Agrobiología, Consejo Superior de Investigaciones Científicas Sevilla, Spain
| | - Ara Kooser
- Department of Biology, University of New Mexico Albuquerque, NM, USA
| | - Diana E Northup
- Department of Biology, University of New Mexico Albuquerque, NM, USA
| | - Valme Jurado
- Instituto de Recursos Naturales y Agrobiología, Consejo Superior de Investigaciones Científicas Sevilla, Spain
| | | | - Cesareo Saiz-Jimenez
- Instituto de Recursos Naturales y Agrobiología, Consejo Superior de Investigaciones Científicas Sevilla, Spain
| | - Naowarat Cheeptham
- Department of Biological Sciences, Faculty of Science, Thompson Rivers University Kamloops, BC, Canada
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Characterization of bacterial diversity associated with calcareous deposits and drip-waters, and isolation of calcifying bacteria from two Colombian mines. Microbiol Res 2015; 182:21-30. [PMID: 26686610 DOI: 10.1016/j.micres.2015.09.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Revised: 09/16/2015] [Accepted: 09/26/2015] [Indexed: 11/21/2022]
Abstract
Bacterial carbonate precipitation has implications in geological processes and important biotechnological applications. Bacteria capable of precipitating carbonates have been isolated from different calcium carbonate deposits (speleothems) in caves, soil, freshwater and seawater around the world. However, the diversity of bacteria from calcareous deposits in Colombia, and their ability to precipitate carbonates, remains unknown. In this study, conventional microbiological methods and molecular tools, such as temporal temperature gradient electrophoresis (TTGE), were used to assess the composition of bacterial communities associated with carbonate deposits and drip-waters from two Colombian mines. A genetic analysis of these bacterial communities revealed a similar level of diversity, based on the number of bands detected using TTGE. The dominant phylogenetic affiliations of the bacteria, determined using 16S rRNA gene sequencing, were grouped into two phyla: Proteobacteria and Firmicutes. Within these phyla, seven genera were capable of precipitating calcium carbonates: Lysinibacillus, Bacillus, Strenotophomonas, Brevibacillus, Methylobacterium, Aeromicrobium and Acinetobacter. FTIR and SEM/EDX were used to analyze calcium carbonate crystals produced by isolated Acinetobacter gyllenbergii. The results showed that rhombohedral and angular calcite crystals with sizes of 90μm were precipitated. This research provides information regarding the presence of complex bacterial communities in secondary carbonate deposits from mines and their ability to precipitate calcium carbonate from calcareous deposits of Colombian mines.
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Vaughan MJ, Nelson W, Soderlund C, Maier RM, Pryor BM. Assessing fungal community structure from mineral surfaces in Kartchner Caverns using multiplexed 454 pyrosequencing. MICROBIAL ECOLOGY 2015; 70:175-187. [PMID: 25608778 DOI: 10.1007/s00248-014-0560-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2014] [Accepted: 12/23/2014] [Indexed: 06/04/2023]
Abstract
Research on the distribution and structure of fungal communities in caves is lacking. Kartchner Caverns is a wet and mineralogically diverse carbonate cave located in an escarpment of Mississippian Escabrosa limestone in the Whetstone Mountains, Arizona, USA. Fungal diversity from speleothem and rock wall surfaces was examined with 454 FLX Titanium sequencing technology using the Internal Transcribed Spacer 1 as a fungal barcode marker. Fungal diversity was estimated and compared between speleothem and rock wall surfaces, and its variation with distance from the natural entrance of the cave was quantified. Effects of environmental factors and nutrient concentrations in speleothem drip water at different sample sites on fungal diversity were also examined. Sequencing revealed 2,219 fungal operational taxonomic units (OTUs) at the 95% similarity level. Speleothems supported a higher fungal richness and diversity than rock walls. However, community membership and the taxonomic distribution of fungal OTUs at the class level did not differ significantly between speleothems and rock walls. Both OTU richness and diversity decreased significantly with increasing distance from the natural cave entrance. Community membership and taxonomic distribution of fungal OTUs also differed significantly between the sampling sites closest to the entrance and those furthest away. There was no significant effect of temperature, CO2 concentration, or drip water nutrient concentration on fungal community structure on either speleothems or rock walls. Together, these results suggest that proximity to the natural entrance is a critical factor in determining fungal community structure on mineral surfaces in Kartchner Caverns.
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Rusman Y, Held BW, Blanchette RA, Wittlin S, Salomon CE. Soudanones A-G: Antifungal Isochromanones from the Ascomycetous Fungus Cadophora sp. Isolated from an Iron Mine. JOURNAL OF NATURAL PRODUCTS 2015; 78:1456-1460. [PMID: 26035018 DOI: 10.1021/acs.jnatprod.5b00204] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
One new isochromane (pseudoanguillosporin C, 2), seven isochromanones (soudanones A-G, 3-9), and six known analogues including 10 and 11 were isolated from a culture of the fungus Cadophora sp. 10-5-2 M, collected from the subterranean 10th level of the Soudan Underground Iron Mine in Minnesota. All of the compounds were tested against a panel of microbial pathogens, and 2, 3, 10, and 11 were found to have activity against Cryptococcus neoformans (MIC = 35, 40, 20, and 30 μg/mL, respectively). Compound 11 was also active against Candida albicans, with an MIC of 40 μg/mL.
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Affiliation(s)
- Yudi Rusman
- †Center for Drug Design, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Benjamin W Held
- ‡Department of Plant Pathology, University of Minnesota, Saint Paul, Minnesota 55108, United States
| | - Robert A Blanchette
- ‡Department of Plant Pathology, University of Minnesota, Saint Paul, Minnesota 55108, United States
| | | | - Christine E Salomon
- †Center for Drug Design, University of Minnesota, Minneapolis, Minnesota 55455, United States
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Wu Y, Tan L, Liu W, Wang B, Wang J, Cai Y, Lin X. Profiling bacterial diversity in a limestone cave of the western Loess Plateau of China. Front Microbiol 2015; 6:244. [PMID: 25870592 PMCID: PMC4378288 DOI: 10.3389/fmicb.2015.00244] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Accepted: 03/12/2015] [Indexed: 11/25/2022] Open
Abstract
Bacteria and archaea sustain subsurface cave ecosystems by dominating primary production and fueling biogeochemical cyclings, despite the permanent darkness and shortage of nutrients. However, the heterogeneity and underlying mechanism of microbial diversity in caves, in particular those well connect to surface environment are largely unexplored. In this study, we examined the bacterial abundance and composition in Jinjia Cave, a small and shallow limestone cave located on the western Loess Plateau of China, by enumerating and pyrosequencing small subunit rRNA genes. The results clearly reveal the contrasting bacterial community compositions in relation to cave habitat types, i.e., rock wall deposit, aquatic sediment, and sinkhole soil, which are differentially connected to the surface environment. The deposits on the cave walls were dominated by putative cave-specific bacterial lineages within the γ-Proteobacteria or Actinobacteria that are routinely found on cave rocks around the world. In addition, sequence identity with known functional groups suggests enrichments of chemolithotrophic bacteria potentially involved in autotrophic C fixation and inorganic N transformation on rock surfaces. By contrast, bacterial communities in aquatic sediments were more closely related to those in the overlying soils. This is consistent with the similarity in elemental composition between the cave sediment and the overlying soil, implicating the influence of mineral chemistry on cave microhabitat and bacterial composition. These findings provide compelling molecular evidence of the bacterial community heterogeneity in an East Asian cave, which might be controlled by both subsurface and surface environments.
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Affiliation(s)
- Yucheng Wu
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science - Chinese Academy of Sciences, Nanjing China
| | - Liangcheng Tan
- State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment - Chinese Academy of Sciences, Xi'an China ; State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment - Chinese Academy of Sciences, Xi'an China
| | - Wuxing Liu
- Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science - Chinese Academy of Sciences, Nanjing China
| | - Baozhan Wang
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science - Chinese Academy of Sciences, Nanjing China
| | - Jianjun Wang
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology - Chinese Academy of Sciences, Nanjing China
| | - Yanjun Cai
- State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment - Chinese Academy of Sciences, Xi'an China
| | - Xiangui Lin
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science - Chinese Academy of Sciences, Nanjing China
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Okyay TO, Rodrigues DF. Biotic and abiotic effects on CO2 sequestration during microbially-induced calcium carbonate precipitation. FEMS Microbiol Ecol 2015; 91:fiv017. [PMID: 25764465 DOI: 10.1093/femsec/fiv017] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/03/2015] [Indexed: 11/13/2022] Open
Abstract
In this study, CO2 sequestration was investigated through the microbially-induced calcium carbonate precipitation (MICP) process with isolates obtained from a cave called 'Cave Without A Name' (Boerne, TX, USA) and the Pamukkale travertines (Denizli, Turkey). The majority of the bacterial isolates obtained from these habitats belonged to the genera Sporosarcina, Brevundimonas, Sphingobacterium and Acinetobacter. The isolates were investigated for their capability to precipitate calcium carbonate and sequester CO2. Biotic and abiotic effects of CO2 sequestration during MICP were also investigated. In the biotic effect, we observed that the rate and concentration of CO2 sequestered was dependent on the species or strains. The main abiotic factors affecting CO2 sequestration during MICP were the pH and medium components. The increase in pH led to enhanced CO2 sequestration by the growth medium. The growth medium components, on the other hand, were shown to affect both the urease activity and CO2 sequestration. Through the Plackett-Burman experimental design, the most important growth medium component involved in CO2 sequestration was determined to be urea. The optimized medium composition by the Plackett-Burman design for each isolate led to a statistically significant increase, of up to 148.9%, in CO2 uptake through calcification mechanisms.
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Affiliation(s)
- Tugba Onal Okyay
- Department of Civil and Environmental Engineering, University of Houston, Houston, TX 77204-4003, USA
| | - Debora F Rodrigues
- Department of Civil and Environmental Engineering, University of Houston, Houston, TX 77204-4003, USA
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Making a living while starving in the dark: metagenomic insights into the energy dynamics of a carbonate cave. ISME JOURNAL 2013; 8:478-91. [PMID: 24030597 DOI: 10.1038/ismej.2013.159] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2013] [Revised: 08/03/2013] [Accepted: 08/12/2013] [Indexed: 01/06/2023]
Abstract
Carbonate caves represent subterranean ecosystems that are largely devoid of phototrophic primary production. In semiarid and arid regions, allochthonous organic carbon inputs entering caves with vadose-zone drip water are minimal, creating highly oligotrophic conditions; however, past research indicates that carbonate speleothem surfaces in these caves support diverse, predominantly heterotrophic prokaryotic communities. The current study applied a metagenomic approach to elucidate the community structure and potential energy dynamics of microbial communities, colonizing speleothem surfaces in Kartchner Caverns, a carbonate cave in semiarid, southeastern Arizona, USA. Manual inspection of a speleothem metagenome revealed a community genetically adapted to low-nutrient conditions with indications that a nitrogen-based primary production strategy is probable, including contributions from both Archaea and Bacteria. Genes for all six known CO2-fixation pathways were detected in the metagenome and RuBisCo genes representative of the Calvin-Benson-Bassham cycle were over-represented in Kartchner speleothem metagenomes relative to bulk soil, rhizosphere soil and deep-ocean communities. Intriguingly, quantitative PCR found Archaea to be significantly more abundant in the cave communities than in soils above the cave. MEtaGenome ANalyzer (MEGAN) analysis of speleothem metagenome sequence reads found Thaumarchaeota to be the third most abundant phylum in the community, and identified taxonomic associations to this phylum for indicator genes representative of multiple CO2-fixation pathways. The results revealed that this oligotrophic subterranean environment supports a unique chemoautotrophic microbial community with potentially novel nutrient cycling strategies. These strategies may provide key insights into other ecosystems dominated by oligotrophy, including aphotic subsurface soils or aquifers and photic systems such as arid deserts.
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