Pieter T Visscher

Pieter T Visscher
University of Connecticut | UConn · Department of Marine Sciences

MSc, PhD

About

200
Publications
50,262
Reads
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12,546
Citations
Additional affiliations
February 2009 - present
UNSW Sydney
Position
  • Member, visiting scientist
August 1994 - present
University of Connecticut
Position
  • Professor (Full)
Description
  • Biogeochemistry, astrobiology and geomicrobiology
May 1991 - September 1992
University of Miami
Position
  • PostDoc Position

Publications

Publications (200)
Article
Full-text available
The role of culture conditions on the production of exopolymeric substances (EPS) by Synechococcus strain PCC7942 was investigated. Carbonate mineral precipitation in these EPS was assessed in forced precipitation experiments. Cultures were grown in HEPES-buffered medium and non-buffered medium. The pH of buffered medium remained constant at 7.5, b...
Article
Full-text available
Storm disturbance and recovery of the peritidal benthic microbial ecosystem occurs as part of the natural climate regime in Shark Bay. However, tropical cyclone and winter storm frequency and intensity are known to be changing due to climate forcing. Presented here is an analysis of the biogeomorphic response of the benthic microbial ecosystem with...
Article
A variety of Mg-, Na- and Ca-sulfates, including gypsum, and Mg-clays precipitate within the microbial mats that developed seasonally in the hypersaline playa lake El Longar (Central Spain). A multidisciplinary study of the microbial mats along a transect of the lake demonstrates that the degree of lithification of the mats increases from the soft...
Article
Shark Bay, Western Australia, is episodically impacted by tropical cyclones. During 2015, the region was hit by a category 3 cyclone, “severe tropical cyclone Olywn,” leading to the formation of a black sludge in an intertidal zone harboring microbial mats and microbialites. Upon returning to the impacted site 12 months later, the black sludge depo...
Conference Paper
Cyanobacteria are major contributors to precipitation of minerals forming biogenic carbonates. The photosynthetic activity of cyanobacteria increases pH, favoring CaCO3 precipitation. These phototrophs produce copious amounts of exopolymeric substances (EPS) with a strong binding capacity for cations such as Ca2+. Environmental conditions (e.g., pH...
Article
Full-text available
Microbial mat communities possess extensive taxonomic and functional diversity, which drive high metabolic rates and rapid cycling of major elements. Modern microbial mats occurring in hypersaline environments are considered as analogs to extinct geobiological formations dating back to ∼ 3.5 Gyr ago. Despite efforts to understand the diversity and...
Article
Full-text available
The earliest evidence of life captured in lithified microbial mats (microbialites) predates the onset of oxygen production and yet, modern oxygenic mats are often studied as analogs based on their morphological similarity and their sedimentological and biogeochemical context. Despite their structural similarity to fossil microbialites, the presence...
Article
Full-text available
Background: Shark Bay, Australia, harbours one of the most extensive and diverse systems of living microbial mats that are proposed to be analogs of some of the earliest ecosystems on Earth. These ecosystems have been shown to possess a substantial abundance of uncultivable microorganisms. These enigmatic microbes, jointly coined as 'microbial dar...
Article
Stromatolites are geobiological systems formed by complex microbial communities, and fossilized stromatolites provide a record of some of the oldest life on Earth. Microbial mats are precursors of extant stromatolites; however, the mechanisms of transition from mat to stromatolite are controversial and are still not well understood. To fully recogn...
Preprint
Full-text available
Shark Bay, Australia, harbours one of the most extensive and diverse systems of living microbial mats, that are proposed to be analogs of some of the earliest ecosystems on Earth. These ecosystems have been shown to possess a substantial abundance of uncultivable microorganisms. These enigmatic groups - microbial dark matter (MDM) - are hypothesise...
Article
Full-text available
In sedimentary environments, clay and sand are segregated by hydrodynamic processes. Yet, clay coats, thin clay envelopes lining sand grains, are abundant in modern and ancient coastal sedimentary deposits. Here, we present laboratory experiments in which we produced clay-coated quartz sands similar to those observed in modern and ancient estuarine...
Chapter
The Salar de Atacama depression is a unique geomorphologic structure in northern Chile and is the oldest and largest evaporitic basin in that country. In the lowest region of the Atacama basin, groundwater surfaces forms a series of lakes that are exposed to the extreme conditions of the salar, including high ultraviolet radiation, low humidity, hi...
Chapter
Laguna Tebenquiche is one of the largest waterbodies in the Salar de Atacama. The prokaryotic microorganisms inhabiting this lake are subjected to extreme conditions such as high solar radiation due to a lower barometric pressure at high altitude, extreme daily temperature fluctuations, severe changes in salinity caused by net evaporation, and high...
Article
Arsenic is best known as an environmental toxin, but this element could also serve as a metabolic energy source to certain microorganisms. Moreover, As cycling may have driven microbial life on early Earth prior to oxygenation of the atmosphere. Still, little is known about the arsenic cycling processes occurring in the presence of microorganisms a...
Article
Full-text available
The Messinian microbialites of the Terminal Carbonate Complex (TCC) from the Neogene basins of southeastern Spain show both diversified morphologies and an excellent preservation of primary microbial microstructures. Their stratigraphic architecture, fabric (micro-, meso-, and macro-fabric), and mineralogical composition were investigated in eight...
Article
The Late Jurassic was a period of major global carbon cycle perturbations with episodes of anoxia leading to regional accumulation of organic matter in sediments worldwide. The Tubiegatan section (SW Gissar Mountains, Uzbekistan) located in the Northern Tethys, shows atypical organic-rich limestone and marl deposits (up to 6% of total organic carbo...
Article
Full-text available
The southern part of the tropical Cayo Coco Island (Cuba) hosts a complex, highly evaporative and marine-fed lagoonal network. In the easternmost lagoon of this network, hypersaline conditions favour the development of complex sedimentary microbial ecosystems within the water column at the bottom water-sediment interface and on the shore. Some of t...
Article
Most source‐to‐sink studies typically focus on the dynamics of clastic sediments and consider erosion, transport and deposition of sediment particles as the sole contributors. Although often neglected, dissolved solids produced by weathering processes contribute significantly in the sedimentary dynamics of basins, supporting chemical and/or biologi...
Article
The World Heritage microbialites, coquinas, and microbialitic-sediments of Hamelin Pool, Shark Bay, Western Australia, form through complex community and environmental interactions resulting in surficial CO2 sequestration. Predicted climate-change impacts threaten the stability of this setting and the balance of biogeomorphological processes that g...
Article
Full-text available
: Mixed cyanobacteria-dominated biofilms, enriched from a tributary of the Mérantaise (France) were used to conduct laboratory experiments in order to understand the relationship between the morphology of carbonate precipitates and the biological activity (e.g., cyanobacterial exopolymeric substances (EPS) production, photosynthetic pH increases)....
Article
Full-text available
The relationship between environmental conditions and the development, mineralization and preservation of modern tufa microbialites was investigated in a 1.1 km long freshwater stream in Villiers-le-Bâcle, a tributary of Mérantaise river. Detailed mapping of the tufa microbialite distribution combined with sedimentological, petrographical and miner...
Article
Full-text available
Sedimentary molybdenum (Mo) isotope compositions are a promising paleoredox indicator as the Mo isotope composition of seawater reflects the balance between anoxic and oxic sinks. Most available data are from shales, however the Mo isotope composition of carbonates also reflects the composition of ancient seawater. Here we provide an expanded datas...
Article
Full-text available
Quorum sensing is a potent system of genetic control allowing phenotypes to be coordinated across localized communities. In this study, quorum sensing systems in Shark Bay microbial mats were delineated using a targeted approach analyzing whole mat extractions as well as the creation of an isolate library. A library of 165 isolates from different m...
Data
Coloured figures for the paper: Disentangling the drivers of functional complexity at the metagenomic level in Shark Bay microbial mat microbiomes
Article
Full-text available
The functional metagenomic potential of Shark Bay microbial mats was examined for the first time at a millimeter scale, employing shotgun sequencing of communities via the Illumina NextSeq 500 platform in conjunction with defined chemical analyses. A detailed functional metagenomic profile has elucidated key pathways and facilitated inference of cr...
Article
Full-text available
In modern stromatolites, mineralization results from a complex interplay between microbial metabolisms, the organic matrix, and environmental parameters. Here, we combined biogeochemical, mineralogical, and microscopic analyses with measurements of metabolic activity to characterize the mineralization processes and products in an emergent (<18 mont...
Article
Full-text available
The Bonneville Basin is a continental lacustrine system accommodating extensive microbial carbonate deposits corresponding to two distinct phases: the deep Lake Bonneville (30,000 to 11,500 ¹⁴C BP) and the shallow Great Salt Lake (since 11,500 ¹⁴C BP). A characterization of these microbial deposits and their associated sediments provides insights i...
Article
The Limagne Basin (French Massif Central) is an extensive continental lacustrine system accommodating microbial and metazoan buildups from Chattian to Aquitanian age. A description of these buildups and their associated biotic components in Grand Gandaillat and Crechy quarries provides insights into their spatio-temporal distribution patterns. Flat...
Article
Understanding how microorganisms adapted to the high arsenic concentration present on early Earth requires understanding of the processes involved in the arsenic biogeochemical cycle operating in living microbial mats. To this end, we investigated a living microbial mat from Laguna Brava (Salar de Atacama, Chile), a hypersaline lake with high arsen...
Article
Full-text available
Interactions of the microbial mat community with the sedimentary environment were evaluated in two shallow, ephemeral lakes with markedly different hydrochemistry and mineralogy. The characterization of growing and decaying microbial mats by light microscopy observations and fluorescence in situ hybridization was complemented with biogeochemical an...
Article
Full-text available
Benthic microbial ecosystems of Laguna La Brava, Salar de Atacama, a high altitude hypersaline lake, were characterized in terms of bacterial and archaeal diversity, biogeochemistry, (including O2 and sulfide depth profiles and mineralogy), and physicochemical characteristics. La Brava is one of several lakes in the Salar de Atacama where microbial...
Data
Bacterial functional diversity abundance on each layer from NLM. Diversity is disclosed at several taxonomic levels. Each group is displayed separately: oxygenic phototrophs, anoxygenic phototrophs, aerobic heterotrophs, anaerobic heterotrophs, fermenters, and sulfate reducers. (TIF)
Data
Bacterial functional diversity abundance on each layer from BM. Diversity is disclosed at several taxonomic levels. Each group is displayed separately: oxygenic phototrophs, anoxygenic phototrophs, aerobic heterotrophs, anaerobic heterotrophs, fermenters, and sulfate reducers. (TIF)
Data
Porewater polysulfides and thiosulfate comparison between LaBrava and Tebenquiche. (XLSX)
Data
OTU table and taxonomic assignment for bulk samples. (XLSX)
Data
Scanning electron micrographs of diatoms. Surface of BM (Panel A) and NLM (Panel B). (TIF)
Data
Taxonomic profiles at phylum level of La Brava and Tebenquiche samples. Samples from different campaigns are shown. (TIF)
Data
Mineral content of bulk and layer samples. (XLSX)
Data
Diversity metrics for the layers belonging to samples NLM and BM, using 16S rDNA V4 region sequences clustered at similarity level of 0.97 and normalized to 1,800 sequences per sample. (XLSX)
Conference Paper
Full-text available
Arsenic is a notorious toxic element, and as such may have exerted a strong selective pressure on the distribution and evolution of life on Earth. Documenting the abundance, distribution, speciation and inter-element correlation of arsenic in living microbial mats could help to understand how arsenic metabolic system works and to evaluate its use a...
Article
Full-text available
Thrombolites are buildups of carbonate that exhibit a clotted internal structure formed through the interactions of microbial mats and their environment. Despite recent advances, we are only beginning to understand the microbial and molecular processes associated with their formation. In this study, a spatial profile of the microbial and metabolic...
Article
Full-text available
The role of archaea in microbial mats is poorly understood. Delineating the spatial distribution of archaea with mat depth will enable resolution of putative niches in these systems. In the present study, high throughput amplicon sequencing was undertaken in conjunction with analysis of key biogeochemical properties of two mats (smooth and pustular...
Article
Full-text available
The use of metals as biosignatures in the fossil stromatolite record requires understanding of the processes controlling the initial metal(loid) incorporation and diagenetic preservation in living microbialites. Here, we report the distribution of metals and the organic fraction within the lithifying microbialite of the hypersaline Big Pond Lake (B...
Article
Full-text available
The Great Salt Lake is a modern hypersaline lake, in which an extended modern and ancient microbial sedimen- tary system has developed. Detailed mapping based on aerial images and field observations can be used to identify non- random distribution patterns of microbial deposits, such as paleoshorelines associated with extensive polygons or fault- p...
Article
Full-text available
We combined nucleic acid-based molecular methods, biogeochemical measurements, and physicochemical characteristics to investigate microbial sedimentary ecosystems of Laguna Tebenquiche, Atacama Desert, Chile. Molecular diversity, and biogeochemistry of hypersaline microbial mats, rhizome-associated concretions, and an endoevaporite were compared wi...
Data
Rarefaction curves plotting the number of observed OTUs as a function of the number of sequences in microbial mats (MA1 and MA2), rhizome-associated lithified concretions (RAC1 and RAC2) and evaporite (EVD).
Data
Rarefaction curves plotting the number of observed OTUs as a function of the number of sequences. (A) Rarefaction curves by layers in MA1. (B) Rarefaction curves by layers in EVD.
Data
Abundant microbial OTUs classified at the lowest possible taxonomic level in EVD. Each OTU contains at less 1% 16S rRNA sequences.
Data
Abundant microbial OTUs classified at the lowest possible taxonomic level in MA1. Each OTU contains at less 1% 16S rRNA sequences.
Data
Physico-chemical parameters for the overlying water from the different samples studied.
Data
Observed microbial richness and diversity estimates based on 97% OTU clusters in microbial mats (MA1 and MA2), rhizome-associated lithified mats (RAC1 and RAC2) and evaporite (EVD).
Article
Full-text available
Microbialites are widespread in modern and fossil hypersaline environments, where they provide a unique sedimentary archive. Authigenic mineral precipitation in modern microbialites results from a complex interplay between microbial metabolisms, organic matrices and environmental parameters. Here, we combined mineralogical and microscopic analyses...
Article
The Great Salt Lake, Utah, USA is a shallow, hypersaline, intracontinental lake hosting extensive microbial deposits. At a large spatial scale, the distribution of these deposits is driven by environmental and geodynamical factors (i.e. water-level fluctuations and a fault-related framework). A detailed mapping of the Buffalo Point area, in the nor...
Article
Full-text available
The Great Salt Lake is a modern hypersaline system in which an extended modern and ancient microbial sedimentary system has developed. Detailed mapping based on aerial images and field observations can be used to identify non-random distribution patterns of microbial deposits, such as paleoshorelines associated with extensive polygons or fault-para...
Article
Full-text available
Modern microbial mats can provide key insights into early Earth ecosystems, and Shark Bay, Australia, holds one of the best examples of these systems. Identifying the spatial distribution of microorganisms with mat depth facilitates a greater understanding of specific niches and potentially novel microbial interactions. High throughput sequencing c...
Article
Full-text available
Active, carbonate-mineralizing microbial mats flourish in a tropical, highly evaporative, marine-fed lagoonal network to the south of Cayo Coco Island (Cuba). Hypersaline conditions support the development of a complex sedimentary microbial ecosystem with diverse morphologies, a variable intensity of mineralization and a potential for preservation....