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Smectitization as a Trigger of Bacterially Mediated Mn-Fe Micronodule Generation in Felsic Glass (Livno-Tomislavgrad Paleolake, Bosnia and Herzegovina). MINERALS 2020. [DOI: 10.3390/min10100899] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Miocene tuffs preserved in argillaceous sediment interbedded with lacustrine successions are commonly encountered throughout the Dinarides Lake System (DLS) in south-eastern Europe. In this contribution the volcanic glass degradation and co-genetic Mn-Fe precipitation were studied in a 14.68 Ma felsic tuff from DLS Livno-Tomislavgrad Basin. Microbial activity has been involved in both reactions thus adding the interest of revealing effects of biotic and abiotic processes taking place during tuff eogenesis. X-ray diffraction and electron microbeam analysis with energy-dispersive X-ray spectroscopy revealed the pitting or granular structures developed at glass rims along with smectite flakes protruding from a degrading glass. Mn-Fe mineralization emerges in the form of Mn-Fe coatings, an initial step to micronodule formation, where traces of biogenetic influence included a high content of phases rich in structural Mn (IV) (i.e., ranciéite and jacobsite) and presence of microbial microfossils. Co-genetic ties between glass degradation and Mn-Fe precipitation were established through the report of dioctahedral smectite formed out of altered glass; which then served as nuclei of the ongoing biotic and abiotic Mn-Fe mineralization. These processes manifest on a continuous involvement of microbial life in the course of eogenesis of pyroclastic material in lacustrine environments.
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Greenfield SR, Tighe SW, Bai Y, Goerlitz DS, Von Turkovich M, Taatjes DJ, Dragon JA, Johnson SS. Life and its traces in Antarctica's McMurdo Dry Valley paleolakes: a survey of preservation. Micron 2019; 131:102818. [PMID: 31968300 DOI: 10.1016/j.micron.2019.102818] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Accepted: 12/24/2019] [Indexed: 01/21/2023]
Abstract
The extremely cold and arid conditions of Antarctica make it uniquely positioned to investigate fundamental questions regarding the persistence of life in extreme environments. Within the McMurdo Dry Valleys and surrounding mountain ranges are multiple ancient relict lakes, paleolakes, with lacustrine deposits spanning from thousands to millions of years in age. Here we present data from light microscopy, scanning electron microscopy, electron dispersive x-ray spectroscopy, and radiocarbon dating to catalog the remarkable range of life preserved within these deposits. This includes intact microbes and nanobacteria-sized cocci, CaCO3 precipitations consistent with biogenic calcium, previously undescribed net-like structures, possible dormant spores, and long-extinct yet exquisitely preserved non-vascular plants. These images provide an important reference for further microbiome investigations of Antarctic paleolake samples. In addition, these findings may provide a visual reference for the use of subsurface groundwater microbial communities as an analog for paleolake subsurface water on planets such as Mars.
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Affiliation(s)
| | - Scott W Tighe
- Vermont Integrative Genomics, University of Vermont, Burlington, VT, 05405 USA
| | - Yu Bai
- Department of Biology, Georgetown University, Washington DC 20057 USA
| | - David S Goerlitz
- Georgetown University Medical Center, Georgetown University, Washington DC, 20057 USA
| | - Michele Von Turkovich
- Department of Pathology and Laboratory Medicine, USA; Microscopy Imaging Center, Larner College of Medicine, University of Vermont, Burlington, VT 05405 USA
| | - Douglas J Taatjes
- Department of Pathology and Laboratory Medicine, USA; Microscopy Imaging Center, Larner College of Medicine, University of Vermont, Burlington, VT 05405 USA
| | - Julie A Dragon
- Vermont Integrative Genomics, University of Vermont, Burlington, VT, 05405 USA; Department of Microbiology and Molecular Genetics, Larner College of Medicine, University of Vermont, Burlington, VT, 05405 USA
| | - Sarah Stewart Johnson
- Department of Biology, Georgetown University, Washington DC 20057 USA; Science, Technology, and International Affairs Program, Georgetown University, Washington DC, 20057 USA
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Esposito A, Borruso L, Rattray JE, Brusetti L, Ahmed E. Taxonomic and functional insights into rock varnish microbiome using shotgun metagenomics. FEMS Microbiol Ecol 2019; 95:5626342. [DOI: 10.1093/femsec/fiz180] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Accepted: 11/13/2019] [Indexed: 12/21/2022] Open
Abstract
ABSTRACTRock varnish is a microbial habitat, characterised by thin (5–500 μm) and shiny coatings of iron (Fe) and manganese (Mn) oxides associated with clay minerals. This structure is well studied by geologists, and recently there have been reports about the taxonomical composition of its microbiome. In this study, we investigated the rock varnish microbiome using shotgun metagenomics together with analyses of elemental composition, lipid and small molecule biomarkers, and rock surface analyses to explore the biogeography of microbial communities and their functional features. We report taxa and encoded functions represented in metagenomes retrieved from varnish or non-varnish samples, additionally, eight nearly complete genomes have been reconstructed spanning four phyla (Acidobacteria, Actinobacteria, Chloroflexi and TM7). The functional and taxonomic analyses presented in this study provide new insights into the ecosystem dynamics and survival strategies of microbial communities inhabiting varnish and non-varnish rock surfaces.
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Affiliation(s)
- Alfonso Esposito
- Department of Cellular, Computational and Integrative Biology – CIBIO – University of Trento, Via Sommarive 9, 38123 Trento, Italy
| | - Luigimaria Borruso
- Faculty of Science and Technology, Free University of Bozen/Bolzano, piazza Università 5, 39100 Bolzano, Italy
| | - Jayne E Rattray
- Department of Biological Sciences, University of Calgary, Calgary, AB T2N 1N4, Canada
| | - Lorenzo Brusetti
- Faculty of Science and Technology, Free University of Bozen/Bolzano, piazza Università 5, 39100 Bolzano, Italy
| | - Engy Ahmed
- Institute of Soil Biology, Biology Centre, Czech Academy of Sciences, Na Sádkách 7, 370 05 České Budějovice, Czech Republic
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Villa F, Cappitelli F. The Ecology of Subaerial Biofilms in Dry and Inhospitable Terrestrial Environments. Microorganisms 2019; 7:microorganisms7100380. [PMID: 31547498 PMCID: PMC6843906 DOI: 10.3390/microorganisms7100380] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 09/17/2019] [Accepted: 09/20/2019] [Indexed: 11/23/2022] Open
Abstract
The ecological relationship between minerals and microorganisms arguably represents one of the most important associations in dry terrestrial environments, since it strongly influences major biochemical cycles and regulates the productivity and stability of the Earth’s food webs. Despite being inhospitable ecosystems, mineral substrata exposed to air harbor form complex and self-sustaining communities called subaerial biofilms (SABs). Using life on air-exposed minerals as a model and taking inspiration from the mechanisms of some microorganisms that have adapted to inhospitable conditions, we illustrate the ecology of SABs inhabiting natural and built environments. Finally, we advocate the need for the convergence between the experimental and theoretical approaches that might be used to characterize and simulate the development of SABs on mineral substrates and SABs’ broader impacts on the dry terrestrial environment.
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Affiliation(s)
- Federica Villa
- Department of Food, Environmental and Nutritional Sciences, Università degli Studi di Milano, Via Celoria 2, 20133 Milano, Italy.
| | - Francesca Cappitelli
- Department of Food, Environmental and Nutritional Sciences, Università degli Studi di Milano, Via Celoria 2, 20133 Milano, Italy.
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Esposito A, Ahmed E, Ciccazzo S, Sikorski J, Overmann J, Holmström SJM, Brusetti L. Comparison of Rock Varnish Bacterial Communities with Surrounding Non-Varnished Rock Surfaces: Taxon-Specific Analysis and Morphological Description. MICROBIAL ECOLOGY 2015; 70:741-750. [PMID: 25921518 DOI: 10.1007/s00248-015-0617-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Accepted: 04/16/2015] [Indexed: 06/04/2023]
Abstract
Rock varnish is a thin layer of Fe and Mn oxyhydroxides with embedded clay minerals that contain an increased Mn/Fe ratio compared to that of the Earth's crust. Even if the study of rock varnish has important implications in several fields, the composition of epilithic bacterial communities and the distribution of taxa on varnish surfaces are still not wholly described. The aim of this study was (i) to identify the bacterial taxa which show the greatest variation between varnish and non-varnish environments, collected from the same rock, and (ii) to describe the morphology of epilithic communities through scanning electron microscopy (SEM). Triplicate samples of rock surfaces with varnish and triplicate samples without varnish were collected from five sites in Matsch Valley (South Tyrol, Italy). The V4 region of 16S rRNA gene was analyzed by Illumina sequencing. Fifty-five ubiquitous taxa have been examined to assess variation between varnish and non-varnish. Cyanobacteria, Chloroflexi, Proteobacteria along with minor taxa such as Solirubrobacterales, Conexibaxter, and Rhodopila showed significant variations of abundance, diversity, or both responding to the ecology (presence/absence of varnish). Other taxa, such as the genus Edaphobacter, showed a more marked spatial variation responding to the sampling site. SEM images showed a multitude of bacterial morphologies and structures involved in the process of attachment and creation of a suitable environment for growth. The features emerging from this analysis suggest that the highly oxidative Fe and Mn-rich varnish environment favors anoxigenic autotrophy and establishment of highly specialized bacteria.
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Affiliation(s)
- Alfonso Esposito
- Faculty of Science and Technology, Free University of Bozen-Bolzano, Piazza Università 1, I-39100, Bozen-Bolzano, Italy
| | - Engy Ahmed
- Department of Geological Sciences, Stockholm University, SE-10691, Stockholm, Sweden
| | - Sonia Ciccazzo
- Faculty of Science and Technology, Free University of Bozen-Bolzano, Piazza Università 1, I-39100, Bozen-Bolzano, Italy
| | - Johannes Sikorski
- Leibniz-Institute DSMZ-German Collection of Microorganisms and Cell Cultures, Inhoffenstraße 7 B, D-38124, Braunschweig, Germany
| | - Jörg Overmann
- Leibniz-Institute DSMZ-German Collection of Microorganisms and Cell Cultures, Inhoffenstraße 7 B, D-38124, Braunschweig, Germany
| | - Sara J M Holmström
- Department of Geological Sciences, Stockholm University, SE-10691, Stockholm, Sweden
| | - Lorenzo Brusetti
- Faculty of Science and Technology, Free University of Bozen-Bolzano, Piazza Università 1, I-39100, Bozen-Bolzano, Italy.
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