Modern lacustrine microbialites: Towards a synthesis of aqueous and carbonate geochemistry and mineralogy

Chagas, Anderson A.P.; Webb, Gregory E.; Burne, Robert V.; Southam, Gordon

doi:10.1016/j.earscirev.2016.09.012

Cited by 81 publications

(74 citation statements)

References 187 publications

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“…Precipitation of Mg-silicate within the Qatar mat is likely to have occurred considering the change in pH from highly alkaline in the lagoon water to only mildly alkaline towards to bottom of the mat (cf. Chagas et al, 2016).…”

Section: Clay Mineralsmentioning

confidence: 99%

Carbonate and silicate biomineralization in a hypersaline microbial mat (Mesaieed sabkha, Qatar): Roles of bacteria, extracellular polymeric substances and viruses

Tucker²,

et al. 2017

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In a modern peritidal microbial mat from Qatar, both biomediated carbonates and Mg‐rich clay minerals (palygorskite) were identified. The mat, ca 5 cm thick, shows a clear lamination reflecting different microbial communities. The initial precipitates within the top millimetres of the mat are composed of Ca–Mg–Si–Al–S amorphous nanoparticles (few tens of nanometres) that replace the ultrastructure of extracellular polymeric substances. The extracellular polymeric substances are enriched in the same cations and act as a substrate for mineral nucleation. Successively, crystallites of palygorskite fibres associated with carbonate nanocrystals develop, commonly surrounding bacterial bodies. Micron‐sized crystals of low‐Mg calcite are the most common precipitates, together with subordinate aragonite, very high‐Mg calcite/dolomite and ankerite. Pyrite nanocrystals and framboids are present in the deeper layers of the mat. Calcite crystallites form conical structures, circular to triangular/hexagonal in cross‐section, evolving to crystals with rhombohedral terminations; some crystallite bundles develop into dumb‐bell and stellate forms. Spheroidal organo‐mineral structures are also common within the mat. Nanospheres, a few tens of nanometres in diameter, occur attached to coccoid bacteria and within their cells; these are interpreted as permineralized viruses and could be significant as nuclei for crystallite‐crystal precipitation. Microspheres, 1 to 10 μm in diameter, result from intracellular permineralization within bacteria or the mineralization of the bacteria themselves. Carbonates and clay minerals are commonly aggregated to form peloids, tens of microns in size, surrounded by residual organic matter. Magnesium silicate and carbonate precipitation are likely to have been driven by pH – saturation index – redox changes within the mat, related to microenvironmental chemical changes induced by the microbes – extracellular polymeric substances – viruses and their degradation.

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Section: Clay Mineralsmentioning

confidence: 99%

Carbonate and silicate biomineralization in a hypersaline microbial mat (Mesaieed sabkha, Qatar): Roles of bacteria, extracellular polymeric substances and viruses

Tucker²,

et al. 2017

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“…Modern microbialites occur in a wide variety of lacustrine basins including rift lakes, volcanic maar lakes, and coastal lakes, and under geochemical conditions that are highly variable (pH, alkalinity, salinity, [Ca 2+ ]) (Chagas, Webb, Burne, & Southam, ). Although microbialite depositional environments are diverse, actively accreting microbialites in modern lakes share similar textural characteristics and are typically associated with photosynthetic microbial communities such as cyanobacteria and diatoms (Chagas et al, ). Lake sediments, and carbonates in particular, preserve a variety of geochemical proxies that may be used for reconstruction of lake paleoenvironments (e.g., Newell, Jensen, Frantz, & Vanden Berg, ; Yang et al, ).…”

Section: Introductionmentioning

confidence: 99%

Microbially influenced lacustrine carbonates: A comparison of Late Quaternary Lahontan tufa and modern thrombolite from Fayetteville Green Lake, NY

et al. 2019

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Carbonate microbialites in lakes can serve as valuable indicators of past environments, so long as the biogenicity and depositional setting of the microbialite can be accurately determined. Late Pleistocene to Early Holocene frondose draping tufa deposits from Winnemucca Dry Lake (Nevada, USA), a subbasin of pluvial Lake Lahontan, were examined in outcrop, petrographically, and geochemically to determine whether microbially induced precipitation is a dominant control on deposition. These observations were compared to modern, actively accumulating microbialites from Fayetteville Green Lake (New York, USA) using similar methods. In addition, preserved microbial DNA was extracted from the Lahontan tufa and sequenced to provide a more complete picture of the microbial communities. Tufas are texturally and geochemically similar to modern thrombolitic microbialites from Fayetteville Green Lake, and the stable isotopic composition of organic C, N, inorganic C, and O supports deposition associated with a lacustrine microbial mat environment dominated by photosynthetic processes. DNA extraction and sequencing indicate that photosynthetic microbial builders were present during tufa deposition, primarily Chloroflexi and Proteobacteria with minor abundances of Cyanobacteria and Acidobacteria. Based on the sequencing results, the depositional environment of the tufas can be constrained to the photic zone of the lake, contrasting with some previous interpretations that put tufa formation in deeper waters. Additionally, the presence of a number of mesothermophilic phyla, including Deinococcus–Thermus, indicates that thermal groundwater may have played a role in tufa deposition at sites not previously associated with groundwater influx. The interpretation of frondose tufas as microbially influenced deposits provides new context to interpretations of lake level and past environments in the Lahontan lake basins.

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“…The ability of these microbialite-forming communities to alter their biological and geological environments has enabled these ecosystems to adapt to a wide range of environmental conditions over the course of Earth's history (Walter, 1994;Grotzinger and Knoll, 1999). Microbialites are located throughout the globe in a wide range of habitats (e.g., lacustrine, marine and hypersaline) and their ecological complexity is just now beginning to be revealed through advancements in high-throughput sequencing of the taxonomic and functional gene diversity (Breitbart et al, 2009;Khodadad and Foster, 2012;Petrash et al, 2012;Bernhard et al, 2011;Mobberley et al, 2013;Russell et al, 2014;Valdespino-Castillo et al, 2014;Sagha€ ı et al, 2015;Casaburi et al, 2016;Cerqueda-Garcia and Falcon, 2016;Chagas et al, 2016;Ruvindy et al, 2016;Warden et al, 2016;White et al, 2016;Alcantara-Hern andez et al, 2017;Louyakis et al, 2017).…”

Section: Introductionmentioning

confidence: 99%

A year in the life of a thrombolite: comparative metatranscriptomics reveals dynamic metabolic changes over diel and seasonal cycles

Louyakis

Gourlé

Casaburi

et al. 2017

Environmental Microbiology

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Microbialites are one of the oldest known ecosystems on Earth and the coordinated metabolisms and activities of these mineral-depositing communities have had a profound impact on the habitability of the planet. Despite efforts to understand the diversity and metabolic potential of these systems, there has not been a systematic molecular analysis of the transcriptional changes that occur within a living microbialite over time. In this study, we generated metatranscriptomic libraries from actively growing thrombolites, a type of microbialite, throughout diel and seasonal cycles and observed dynamic shifts in the population and metabolic transcriptional activity. The most transcribed genes in all seasons were associated with photosynthesis, but only transcripts associated with photosystem II exhibited diel cycling. Photosystem I transcripts were constitutively expressed at all time points including midnight and sunrise. Transcripts associated with nitrogen fixation, methanogenesis and dissimilatory sulfate reduction exhibited diel cycling, and variability between seasons. Networking analysis of the metatranscriptomes showed correlated expression patterns helping to elucidate how metabolic interactions are coordinated within the thrombolite community. These findings have identified distinctive temporal patterns within the thrombolites and will serve an important foundation to understand the mechanisms by which these communities form and respond to changes in their environment.

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Modern lacustrine microbialites: Towards a synthesis of aqueous and carbonate geochemistry and mineralogy

Cited by 81 publications

References 187 publications

Carbonate and silicate biomineralization in a hypersaline microbial mat (Mesaieed sabkha, Qatar): Roles of bacteria, extracellular polymeric substances and viruses

Carbonate and silicate biomineralization in a hypersaline microbial mat (Mesaieed sabkha, Qatar): Roles of bacteria, extracellular polymeric substances and viruses

Microbially influenced lacustrine carbonates: A comparison of Late Quaternary Lahontan tufa and modern thrombolite from Fayetteville Green Lake, NY

A year in the life of a thrombolite: comparative metatranscriptomics reveals dynamic metabolic changes over diel and seasonal cycles

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