scholarly journals Selenocysteine, Pyrrolysine, and the Unique Energy Metabolism of Methanogenic Archaea

Archaea ◽  
2010 ◽  
Vol 2010 ◽  
pp. 1-14 ◽  
Author(s):  
Michael Rother ◽  
Joseph A. Krzycki
Keyword(s):  
Energy Metabolism ◽  
Energy Conservation ◽  
Methanogenic Archaea ◽  
Strictly Anaerobic ◽  
Related Research ◽  
Stop Codons ◽  
Anaerobic Microorganisms ◽  
Two Systems ◽  
Recent Developments

Methanogenic archaea are a group of strictly anaerobic microorganisms characterized by their strict dependence on the process of methanogenesis for energy conservation. Among the archaea, they are also the only known group synthesizing proteins containing selenocysteine or pyrrolysine. All but one of the known archaeal pyrrolysine-containing and all but two of the confirmed archaeal selenocysteine-containing protein are involved in methanogenesis. Synthesis of these proteins proceeds through suppression of translational stop codons but otherwise the two systems are fundamentally different. This paper highlights these differences and summarizes the recent developments in selenocysteine- and pyrrolysine-related research on archaea and aims to put this knowledge into the context of their unique energy metabolism.

scholarly journals Lactate metabolism in strictly anaerobic microorganisms with a soluble NAD + ‐dependent L‐lactate dehydrogenase

2021 ◽  
Author(s):  
Florian P. Rosenbaum ◽  
Anja Poehlein ◽  
Richard Egelkamp ◽  
Rolf Daniel ◽  
Sönke Harder ◽  
...  
Keyword(s):  
Lactate Dehydrogenase ◽  
Strictly Anaerobic ◽  
Lactate Metabolism ◽  
Anaerobic Microorganisms

Nano zero-valent iron harms methanogenic archaea by interfering with energy conservation and methanogenesis

2021 ◽  
Author(s):  
Yuanxu Song ◽  
Liangfeng Duan ◽  
Kaifeng Du ◽  
Chao Song ◽  
Shan Zhao ◽  
...  
Keyword(s):  
Oxidative Damage ◽  
Energy Conservation ◽  
Methanogenic Archaea ◽  
Zero Valent Iron ◽  
Pollutant Remediation ◽  
Nano Zero Valent Iron ◽  
Iron Based

Iron-based nanoparticles (Fe-NPs), often applied for pollutant remediation, inevitably interact with various organisms either directly or indirectly. The well-acknowledged toxicological mechanisms for Fe-NPs on organisms are causing oxidative damage and...

scholarly journals A Rapid, Sensitive, Low-Cost Assay for Detecting Hydrogenotrophic Methanogens in Anaerobic Digesters Using Loop-Mediated Isothermal Amplification

2020 ◽  
Vol 8 (5) ◽  
pp. 740
Author(s):  
Anna M. Alessi ◽  
Bing Tao ◽  
Wei Zhang ◽  
Yue Zhang ◽  
Sonia Heaven ◽  
...  
Keyword(s):  
Low Cost ◽  
Quantitative Measure ◽  
Methanogenic Archaea ◽  
High Sensitivity ◽  
Gas Production ◽  
Isothermal Amplification ◽  
Process Conditions ◽  
Strictly Anaerobic ◽  
Loop Mediated Isothermal Amplification ◽  
Hydrogenotrophic Methanogens

Understanding how the presence, absence, and abundance of different microbial genera supply specific metabolic functions for anaerobic digestion (AD) and how these impact on gas production is critical for a long-term understanding and optimization of the AD process. The strictly anaerobic methanogenic archaea are essential for methane production within AD microbial communities. Methanogens are a phylogenetically diverse group that can be classified into three metabolically distinct lineages based on the substrates they use to produce methane. While process optimization based on physicochemical parameters is well established in AD, measurements that could allow manipulation of the underlying microbial community are seldom used as they tend to be non-specific, expensive, or time-consuming, or a combination of all three. Loop-mediated isothermal amplification (LAMP) assays combine a simple, rapid, low-cost detection technique with high sensitivity and specificity. Here, we describe the optimization of LAMP assays for the detection of four different genera of hydrogenotrophic methanogens: Methanoculleus, Methanothermobacter, Methanococcus, and Methanobrevibacter spp. By targeting archaeal elongation factor 2 (aEF2), these LAMP assays provide a rapid, low-cost, presence/absence indication of hydrogenotrophic methanogens that could be used as a real-time measure of process conditions. The assays were shown to be sensitive to 1 pg of DNA from most tested methanogen species, providing a route to a quantitative measure through simple serial dilution of samples. The LAMP assays described here offer a simple, fast, and affordable method for the specific detection of four different genera of hydrogenotrophic methanogens. Our results indicate that this approach could be developed into a quantitative measure that could provide rapid, low-cost insight into the functioning and optimization of AD and related systems.

Workshop no. 1. Alternate metabolic pathways in protozoan energy metabolism

Parasitology ◽  
1981 ◽  
Vol 82 (4) ◽  
pp. 1-30 ◽  
Keyword(s):  
Energy Metabolism ◽  
Metabolic Pathways ◽  
Functional Role ◽  
High Energy ◽  
Strictly Anaerobic ◽  
Factors Affecting ◽  
Subcellular Compartmentation ◽  
Similarities And Differences ◽  
Metabolic Behaviour

The purpose of this workshop was to collect together colleagues investigating the intermediary metabolism of protozoa, with a view to discussing those pathways involved in energy metabolism and the production of ATP and other high-energy compounds, together with the factors affecting energy balance. The aspects of energy metabolism chosen for discussion comprised the metabolic pathways ranging from the strictly anaerobic to highly oxidative; subcellular compartmentation of these pathways within the protozoa; the functional role of these pathways including a consideration of aero-tolerance; and the use of inhibitors as biochemical probes and potential chemotherapeuticagents. Hopefully this approach has produced a broad 'over-view' of important areas of protozoan energy metabolism which will enable both the specialist and non-specialist to appreciate the similarities and differences between the metabolic behaviour of a range of protozoa.

scholarly journals S-Inosyl-l-Homocysteine Hydrolase, a Novel Enzyme Involved inS-Adenosyl-l-Methionine Recycling

2015 ◽  
Vol 197 (14) ◽  
pp. 2284-2291 ◽  
Author(s):  
Danielle Miller ◽  
Huimin Xu ◽  
Robert H. White
Keyword(s):  
Metabolic Pathways ◽  
Methanogenic Archaea ◽  
Metabolite Identification ◽  
Strictly Anaerobic ◽  
Methanocaldococcus Jannaschii ◽  
Content Type ◽  
Sequence Identity ◽  
Feedback Inhibitor ◽  
Recycling Pathway ◽  
Insight Into

ABSTRACTS-Adenosyl-l-homocysteine, the product ofS-adenosyl-l-methionine (SAM) methyltransferases, is known to be a strong feedback inhibitor of these enzymes. A hydrolase specific forS-adenosyl-l-homocysteine producesl-homocysteine, which is remethylated to methionine and can be used to regenerate SAM. Here, we show that the annotatedS-adenosyl-l-homocysteine hydrolase inMethanocaldococcus jannaschiiis specific for the hydrolysis and synthesis ofS-inosyl-l-homocysteine, notS-adenosyl-l-homocysteine. This is the first report of an enzyme specific forS-inosyl-l-homocysteine. As withS-adenosyl-l-homocysteine hydrolase, which shares greater than 45% sequence identity with theM. jannaschiihomologue, theM. jannaschiienzyme was found to copurify with bound NAD+and hasKmvalues of 0.64 ± 0.4 mM, 0.0054 ± 0.006 mM, and 0.22 ± 0.11 mM for inosine,l-homocysteine, andS-inosyl-l-homocysteine, respectively. No enzymatic activity was detected withS-adenosyl-l-homocysteine as the substrate in either the synthesis or hydrolysis direction. These results prompted us to redesignate theM. jannaschiienzyme anS-inosyl-l-homocysteine hydrolase (SIHH). Identification of SIHH demonstrates a modified pathway in this methanogen for the regeneration of SAM fromS-adenosyl-l-homocysteine that uses the deamination ofS-adenosyl-l-homocysteine to formS-inosyl-l-homocysteine.IMPORTANCEIn strictly anaerobic methanogenic archaea, such asMethanocaldococcus jannaschii, canonical metabolic pathways are often not present, and instead, unique pathways that are deeply rooted on the phylogenetic tree are utilized by the organisms. Here, we discuss the recycling pathway forS-adenosyl-l-homocysteine, produced fromS-adenosyl-l-methionine (SAM)-dependent methylation reactions, which uses a hydrolase specific forS-inosyl-l-homocysteine, an uncommon metabolite. Identification of the pathways and the enzymes involved in the unique pathways in the methanogens will provide insight into the biochemical reactions that were occurring when life originated.

Cross-border Patients and Informed Choices on Treatment in English and French Law and the Patients’ Rights Directive

2012 ◽  
Vol 19 (5) ◽  
pp. 467-484 ◽  
Author(s):  
Simon Taylor
Keyword(s):  
European Union ◽  
Patient Rights ◽  
French Law ◽  
European Union Law ◽  
Patient Movement ◽  
Patients Rights ◽  
Cross Border ◽  
Two Systems ◽  
Recent Developments ◽  
Right To Information

Abstract Developments in European Union law have created rules favourable to cross-border patient movement. However, where national laws on patient rights differ, this may limit movement by creating confusion for patients and by reducing their confidence in seeking treatment abroad. This article examines the extent to which English and French law recognize a patient right to information regarding treatment. In light of the differences between the two systems concerning both the form and the content of the law, highlighted by recent developments in French law, the article then considers whether the Patients’ Rights Directive can provide a framework for coordination of national rules.

scholarly journals The Genome Sequence ofMethanohalophilus mahiiSLPTReveals Differences in the Energy Metabolism among Members of theMethanosarcinaceaeInhabiting Freshwater and Saline Environments

Archaea ◽  
2010 ◽  
Vol 2010 ◽  
pp. 1-16 ◽  
Author(s):  
Stefan Spring ◽  
Carmen Scheuner ◽  
Alla Lapidus ◽  
Susan Lucas ◽  
Tijana Glavina Del Rio ◽  
...  
Keyword(s):  
Energy Metabolism ◽  
Genome Sequence ◽  
Salt Lake ◽  
Methanogenic Archaea ◽  
Distinct Species ◽  
Freshwater Species ◽  
Protein Coding ◽  
Hypersaline Sediments ◽  
Methanohalophilus Mahii ◽  
Halophilic Species

Methanohalophilus mahiiis the type species of the genusMethanohalophilus, which currently comprises three distinct species with validly published names.Mhp. mahiirepresents moderately halophilic methanogenic archaea with a strictly methylotrophic metabolism. The type strain SLPTwas isolated from hypersaline sediments collected from the southern arm of Great Salt Lake, Utah. Here we describe the features of this organism, together with the complete genome sequence and annotation. The 2,012,424 bp genome is a single replicon with 2032 protein-coding and 63 RNA genes and part of theGenomic Encyclopedia of Bacteria and Archaeaproject. A comparison of the reconstructed energy metabolism in the halophilic speciesMhp. mahiiwith other representatives of theMethanosarcinaceaereveals some interesting differences to freshwater species.

scholarly journals Early Methanogenic Colonisation in the Faeces of Meishan and Yorkshire Piglets as Determined by Pyrosequencing Analysis

Archaea ◽  
2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Yong Su ◽  
Gaorui Bian ◽  
Zhigang Zhu ◽  
Hauke Smidt ◽  
Weiyun Zhu
Keyword(s):  
Energy Metabolism ◽  
Methanogenic Archaea ◽  
Rrna Gene ◽  
Methanogenic Community ◽  
Neonatal Piglets ◽  
Operational Taxonomic Units ◽  
Faecal Samples ◽  
16S Rrna Gene Pyrosequencing ◽  
Pyrosequencing Analysis ◽  
Early Establishment

Gut methanogenic archaea of monogastric animals are considered to be related to energy metabolism and adipose deposition of the host; however, information on their development in young piglets is limited. Thus, to investigate early methanogenic colonisation in the faeces of Meishan and Yorkshire piglets, faecal samples were collected from piglets at 1, 3, 7, and 14 days after birth and used to analyse the methanogenic community with 16S rRNA gene pyrosequencing. Results showed that the diversity of the methanogenic community in the faeces of neonatal piglets decreased from one to 14 days of age, as the total methanogen populations increased. The age of piglets, but not the breed, significantly affected the diversity of the methanogenic community which was dominated by the genusMethanobrevibacter. From the ages of one to 14 days, the abundance ofM. smithii-related operational taxonomic units (OTUs) increased significantly, while the abundances ofM. thaueri- andM. millerae-related OTUs decreased significantly. The substitution ofM. smithiiforM. thaueri/M. milleraewas faster in Yorkshire piglets than in Meishan piglets. These results suggest that the early establishment of microbiota in neonatal piglets is accompanied by dramatic changes in the methanogenic community, and that the changes vary among pigs of different genotypes.

Sign in / Sign up

Export Citation Format

Share Document