Taxonomic, Phylogenetic, and Ecological Diversity of Methanogenic Archaea

Anaerobe ◽  
2000 ◽  
Vol 6 (4) ◽  
pp. 205-226 ◽  
Author(s):  
Jean-Louis Garcia ◽  
Bharat K.C Patel ◽  
Bernard Ollivier
Keyword(s):  
Methanogenic Archaea ◽  
Ecological Diversity

Methanogen microfossils and methanogenesis in Permian lake deposits

Geology ◽  
2020 ◽  
Vol 49 (1) ◽  
pp. 13-18
Author(s):  
Funing Sun ◽  
Wenxuan Hu ◽  
Xiaolin Wang ◽  
Jian Cao ◽  
Bin Fu ◽  
...  
Keyword(s):  
Lake Sediments ◽  
Metabolic Activity ◽  
Fossil Record ◽  
Methanogenic Archaea ◽  
Ancient Lakes ◽  
Ecological Diversity ◽  
Significant Component ◽  
Biogenic Methane ◽  
Biological Affinity ◽  
Lake Deposits

Abstract Methanogens are methane-producing archaea (some of the most primitive organisms on Earth), which possess great phylogenetic and ecological diversity in modern ecosystems. However, cellular fossil evidence of methanogens remains extremely scarce throughout the geological record. Here, we report a new population of spheroidal microstructures composed of dolomite observed in Permian lake deposits in northwestern China. The microspheres exhibit indicators of biological affinity and are well preserved in authigenic dolomite with cellular fidelity. Based on morphological and geochemical evidence, these microspheres are interpreted as fossilized cells of methanogenic archaea, which can be divided into three size-based taxa. These microfossils are the first fossil record of spheroidal methanogens. The microfossil-bearing dolomite exhibits extremely positive δ13C values (up to +20‰ relative to Vienna Peedee belemnite) that are attributed to microbial methanogenesis. The results suggest that methanogens were a significant component of this Permian lake biosphere. As a consequence of the metabolic activity of the methanogens, a large amount of biogenic methane was produced through methanogenesis in the anoxic lake sediments. This study not only fills a gap in the fossil record of methanogenic archaea, but it also provides new insights into methane emissions from ancient lakes.

scholarly journals Microbial Diversity Dynamics in a Methanogenic-Sulfidogenic UASB Reactor

2021 ◽  
Vol 18 (3) ◽  
pp. 1305
Author(s):  
E. Fernández-Palacios ◽  
Xudong Zhou ◽  
Mabel Mora ◽  
David Gabriel
Keyword(s):  
Paper Industry ◽  
Chemical Species ◽  
Methanogenic Archaea ◽  
Granular Sludge ◽  
Upflow Anaerobic Sludge Blanket ◽  
Uasb Reactor ◽  
Anaerobic Sludge ◽  
Rrna Gene ◽  
Sulfate Reducing ◽  
Long Run

In this study, the long-term performance and microbial dynamics of an Upflow Anaerobic Sludge Blanket (UASB) reactor targeting sulfate reduction in a SOx emissions treatment system were assessed using crude glycerol as organic carbon source and electron donor under constant S and C loading rates. The reactor was inoculated with granular sludge obtained from a pulp and paper industry and fed at a constant inlet sulfate concentration of 250 mg S-SO42−L−1 and a constant C/S ratio of 1.5 ± 0.3 g Cg−1 S for over 500 days. Apart from the regular analysis of chemical species, Illumina analyses of the 16S rRNA gene were used to study the dynamics of the bacterial community along with the whole operation. The reactor was sampled along the operation to monitor its diversity and the changes in targeted species to gain insight into the performance of the sulfidogenic UASB. Moreover, studies on the stratification of the sludge bed were performed by sampling at different reactor heights. Shifts in the UASB performance correlated well with the main shifts in microbial communities of interest. A progressive loss of the methanogenic capacity towards a fully sulfidogenic UASB was explained by a progressive wash-out of methanogenic Archaea, which were outcompeted by sulfate-reducing bacteria. Desulfovibrio was found as the main sulfate-reducing genus in the reactor along time. A progressive reduction in the sulfidogenic capacity of the UASB was found in the long run due to the accumulation of a slime-like substance in the UASB.

scholarly journals Monograph of Carex section Schiedeanae (Cyperaceae): unexpected taxonomic and ecological diversity in a Mexican sedge clade

2021 ◽  
Author(s):  
Anton A. Reznicek ◽  
M. Socorro González‐Elizondo ◽  
Marlene Hahn ◽  
Mira Garner ◽  
Andrew L. Hipp
Keyword(s):  
Ecological Diversity

scholarly journals Black spicules from a new interstitial opheliid polychaete Thoracophelia minuta sp. nov. (Annelida: Opheliidae)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Naoto Jimi ◽  
Shinta Fujimoto ◽  
Mami Takehara ◽  
Satoshi Imura
Keyword(s):  
Developmental Biology ◽  
Phylogenetic Analysis ◽  
New Species ◽  
Morphological Diversity ◽  
The Body ◽  
Evolutionary Significance ◽  
Research Subject ◽  
Ecological Diversity ◽  
Coelomic Cavity ◽  
Molecular Phylogenetic

AbstractThe phylum Annelida exhibits high morphological diversity coupled with its extensive ecological diversity, and the process of its evolution has been an attractive research subject for many researchers. Its representatives are also extensively studied in fields of ecology and developmental biology and important in many other biology related disciplines. The study of biomineralisation is one of them. Some annelid groups are well known to form calcified tubes but other forms of biomineralisation are also known. Herein, we report a new interstitial annelid species with black spicules, Thoracophelia minuta sp. nov., from Yoichi, Hokkaido, Japan. Spicules are minute calcium carbonate inclusions found across the body and in this new species, numerous black rod-like inclusions of calcium-rich composition are distributed in the coelomic cavity. The new species can be distinguished from other known species of the genus by these conspicuous spicules, shape of branchiae and body formula. Further, the new species’ body size is apparently smaller than its congeners. Based on our molecular phylogenetic analysis using 18S and 28S sequences, we discuss the evolutionary significance of the new species’ spicules and also the species' progenetic origin.

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