Tufted microbial (cyanobacterial) mats from the Proterozoic Stoer Group, Scotland

1984 ◽  
Vol 121 (4) ◽  
pp. 351-355 ◽  
Author(s):  
R. L. Upfold
Keyword(s):  
Microbial Mats ◽  
Cyanobacterial Mats ◽  
Preservation Potential

AbstractUpward-thinning stellate and polygonal carbonate structures are described and compared to modern and ancient stromatolites. Although tufted microbial mats are common in modern settings they have rarely been described from ancient rocks owing to their poor preservation potential. The preservation of these from the Stoer Group is due to early replacement by calcite before their original tufted relief could be obliterated by compaction. Associated limestones with some similar features are interpreted as flat to mamillated microbial mats.

scholarly journals Cyanobacterial Mats in Calcite-Precipitating Serpentinite-Hosted Alkaline Springs of the Voltri Massif, Italy

2020 ◽  
Vol 9 (1) ◽  
pp. 62
Author(s):  
Aysha Kamran ◽  
Kathrin Sauter ◽  
Andreas Reimer ◽  
Theresa Wacker ◽  
Joachim Reitner ◽  
...  
Keyword(s):  
Microbial Communities ◽  
Microbial Mats ◽  
Environmental Dna ◽  
Cyanobacterial Mats ◽  
Cyanobacterial Community ◽  
Mineral Precipitation ◽  
Community Based ◽  
Specific Adaptation ◽  
Carbonate Buildups ◽  
Generation Sequencing

(1) Background: Microbial communities in terrestrial, calcifying high-alkaline springs are not well understood. In this study, we investigate the structure and composition of microbial mats in ultrabasic (pH 10–12) serpentinite springs of the Voltri Massif (Italy). (2) Methods: Along with analysis of chemical and mineralogical parameters, environmental DNA was extracted and subjected to analysis of microbial communities based upon next-generation sequencing. (3) Results: Mineral precipitation and microbialite formation occurred, along with mat formation. Analysis of the serpentinite spring microbial community, based on Illumina sequencing of 16S rRNA amplicons, point to the relevance of alkaliphilic cyanobacteria, colonizing carbonate buildups. Cyanobacterial groups accounted for up to 45% of all retrieved sequences; 3–4 taxa were dominant, belonging to the filamentous groups of Leptolyngbyaceae, Oscillatoriales, and Pseudanabaenaceae. The cyanobacterial community found at these sites is clearly distinct from creek water sediment, highlighting their specific adaptation to these environments.

scholarly journals Changes in Quinone Profiles of Hot Spring Microbial Mats with a Thermal Gradient

1999 ◽  
Vol 65 (1) ◽  
pp. 198-205 ◽  
Author(s):  
Akira Hiraishi ◽  
Taichi Umezawa ◽  
Hiroyuki Yamamoto ◽  
Kenji Kato ◽  
Yonosuke Maki
Keyword(s):  
Thermal Gradient ◽  
Microbial Mats ◽  
Hot Springs ◽  
Hot Spring ◽  
Thermal Gradients ◽  
Cyanobacterial Mats ◽  
Dissimilarity Index ◽  
Quinone Profile ◽  
Bacterial Mats ◽  
Different Temperatures

ABSTRACT The respiratory and photosynthetic quinones of microbial mats which occurred in Japanese sulfide-containing neutral-pH hot springs at different temperatures were analyzed by spectrochromatography and mass spectrometry. All of the microbial mats that developed at high temperatures (temperatures above 68°C) were so-called sulfur-turf bacterial mats and produced methionaquinones (MTKs) as the major quinones. A 78°C hot spring sediment had a similar quinone profile.Chloroflexus-mixed mats occurred at temperatures of 61 to 65°C and contained menaquinone 10 (MK-10) as the major component together with significant amounts of either MTKs or plastoquinone 9 (PQ-9). The sunlight-exposed biomats growing at temperatures of 45 to 56°C were all cyanobacterial mats, in which the photosynthetic quinones (PQ-9 and phylloquinone) predominated and MK-10 was the next most abundant component in most cases. Ubiquinones (UQs) were not found or were detected in only small amounts in the biomats growing at temperatures of 50°C and above, whereas the majority of the quinones of a purple photosynthetic mat growing at 34°C were UQs. A numerical analysis of the quinone profiles was performed by using the following three parameters: dissimilarity index (D), microbial divergence index (MDq ), and bioenergetic divergence index (BDq ). A D matrix tree analysis showed that the hot spring mats consisting of the sulfur-turf bacteria, Chloroflexus spp., cyanobacteria, and purple phototrophic bacteria formed distinct clusters. Analyses ofMDq and BDq values indicated that the microbial diversity of hot spring mats decreased as the temperature of the environment increased. The changes in quinone profiles and physiological types of microbial mats in hot springs with thermal gradients are discussed from evolutionary viewpoints.

scholarly journals Evaporative silicification in floating microbial mats: patterns of oxygen production and preservation potential in silica‐undersaturated streams, El Tatio, Chile

Geobiology ◽  
2021 ◽  
Author(s):  
Dylan T. Wilmeth ◽  
Kimberly D. Myers ◽  
Stefan V. Lalonde ◽  
Kaarel Mänd ◽  
Kurt O. Konhauser ◽  
...  
Keyword(s):  
Microbial Mats ◽  
Oxygen Production ◽  
Preservation Potential

scholarly journals Microbial Diversity of a Heavily Polluted Microbial Mat and Its Community Changes following Degradation of Petroleum Compounds

2002 ◽  
Vol 68 (4) ◽  
pp. 1674-1683 ◽  
Author(s):  
Raeid M. M. Abed ◽  
Nimer M. D. Safi ◽  
Jürgen Köster ◽  
Dirk de Beer ◽  
Yasser El-Nahhal ◽  
...  
Keyword(s):  
Microbial Community ◽  
Microbial Diversity ◽  
Significant Role ◽  
Bacterial Communities ◽  
Bacterial Population ◽  
Microbial Mats ◽  
Community Response ◽  
Microbial Mat ◽  
Cyanobacterial Mats ◽  
Community Changes

ABSTRACT We studied the microbial diversity of benthic cyanobacterial mats inhabiting a heavily polluted site in a coastal stream (Wadi Gaza) and monitored the microbial community response induced by exposure to and degradation of four model petroleum compounds in the laboratory. Phormidium- and Oscillatoria-like cyanobacterial morphotypes were dominant in the field. Bacteria belonging to different groups, mainly the Cytophaga-Flavobacterium-Bacteriodes group, the γ and β subclasses of the class Proteobacteria, and the green nonsulfur bacteria, were also detected. In slurry experiments, these communities efficiently degraded phenanthrene and dibenzothiophene completely in 7 days both in the light and in the dark. n-Octadecane and pristane were degraded to 25 and 34% of their original levels, respectively, within 7 days, but there was no further degradation until 40 days. Both cyanobacterial and bacterial communities exhibited noticeable changes concomitant with degradation of the compounds. The populations enriched by exposure to petroleum compounds included a cyanobacterium affiliated phylogenetically with Halomicronema. Bacteria enriched both in the light and in the dark, but not bacteria enriched in any of the controls, belonged to the newly described Holophaga-Geothrix-Acidobacterium phylum. In addition, another bacterial population, found to be a member of green nonsulfur bacteria, was detected only in the bacteria treated in the light. All or some of the populations may play a significant role in metabolizing the petroleum compounds. We concluded that the microbial mats from Wadi Gaza are rich in microorganisms with high biodegradative potential.

scholarly journals Microbial diversity and metabolic potential in cyanotoxin producing cyanobacterial mats throughout a river network

2018 ◽  
Author(s):  
Keith Bouma-Gregson ◽  
Matthew R. Olm ◽  
Alexander J. Probst ◽  
Karthik Anantharaman ◽  
Mary E. Power ◽  
...  
Keyword(s):  
Microbial Mats ◽  
Species Group ◽  
River Network ◽  
Oxygenic Photosynthesis ◽  
River Networks ◽  
Metagenomic Sequencing ◽  
Cyanobacterial Mats ◽  
Metabolic Potential ◽  
Microbial Assemblage ◽  
Cyanobacterial Species

AbstractMicrobial mats formed by Cyanobacteria of the genusPhormidiumproduce the neurotoxin anatoxin-a that has been linked to animal deaths. Blooms of planktonic Cyanobacteria have long been of concern in lakes, but recognition of potential harmful impacts of riverine benthic cyanobacterial mats is more recent. Consequently little is known about the diversity of the biosynthetic capacities of cyanobacterial species and associated microbes in mats throughout river networks. Here we performed metagenomic sequencing for 22Phormidium-dominated microbial mats collected across the Eel River network in Northern California to investigate cyanobacterial and co-occurring microbial assemblage diversity, probe their metabolic potential and evaluate their capacities for toxin production. We genomically defined four Cyanobacterial species clusters that occur throughout the river network, three of which have not been described previously. From the genomes of seven strains from one species group we describe the first anatoxin-a operon from the genusPhormidium. Community composition within the mat appears to be associated with the presence of Cyanobacteria capable of producing anatoxin-a. Bacteroidetes, Proteobacteria, and novel Verrucomicrobia dominated the microbial assemblages. Interestingly, some mats also contained organisms from candidate phyla such asCanditatusKapabacteria, as well as Absconditabacteria (SR1), Parcubacteria (OD1) and Peregrinibacteria (PER) within the Candidate Phyla Radiation. Oxygenic photosynthesis and carbon respiration were the most common metabolisms detected in mats but other metabolic capacities include aerobic anoxygenic photosynthesis, sulfur compound oxidation and breakdown of urea. The results reveal the diversity of metabolisms fueling the growth of mats, and a relationship between microbial assemblage composition and the distribution of anatoxin-a producing cyanobacteria within freshwaterPhormidiummats in river networks.

scholarly journals Community structure of free-floating filamentous cyanobacterial mats from the Wonder Lake geothermal springs in the Philippines

2005 ◽  
Vol 51 (7) ◽  
pp. 583-589 ◽  
Author(s):  
Donnabella C Lacap ◽  
Gavin J.D Smith ◽  
Kimberley Warren-Rhodes ◽  
Stephen B Pointing
Keyword(s):  
Community Structure ◽  
Microbial Mats ◽  
Growth Habit ◽  
Dorsal Surface ◽  
The Philippines ◽  
Morphological Identification ◽  
Cyanobacterial Mats ◽  
Geothermal Springs ◽  
Increasing Temperature ◽  
Ordered Layers

Cyanobacterial mats were characterized from pools of 45–60 °C in near-neutral pH, low-sulphide geothermal springs in the Philippines. Mat structure did not vary with temperature. All mats possessed highly ordered layers of airspaces at both the macroscopic and microscopic level, and these appear to be an adaptation to a free-floating growth habit. Upper mat layers supported biomass with elevated carotenoid:chlorophyll a ratios and an as yet uncharacterized waxy layer on the dorsal surface. Microscopic examination revealed mats comprised a single Fischerella morphotype, with abundant heterocysts throughout mats at all temperatures. Molecular analysis of mat community structure only partly matched morphological identification. All samples supported greater 16S rDNA-defined diversity than morphology suggested, with a progressive loss in the number of genotypes with increasing temperature. Fischerella-like sequences were recovered from mats occurring at all temperatures, but some mats also yielded Oscillatoria-like sequences, although corresponding phenotypes were not observed. Phylogenetic analysis revealed that Fischerella-like sequences were most closely affiliated with Fischerella major and the Oscillatoria-like sequences with Oscillatoria amphigranulata.Key words: cyanobacteria, Fischerella, geothermal springs, microbial mats, Oscillatoria.

Holocene Intertidal Microbial Mats Of Qatar And Their Implications For Petroleum Source Rock Formation In Carbonate-Siliciclastic-Evaporite Systems

2014 ◽  
Author(s):  
Miroslaw Slowakiewicz ◽  
Richard D. Pancost ◽  
Lisa Thomas ◽  
Maurice E. Tucker ◽  
Sher Mey Didi-Ooi ◽  
...  
Keyword(s):  
Source Rock ◽  
Microbial Mats ◽  
Rock Formation ◽  
Petroleum Source Rock
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