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Methanobrevibacter smithii | |
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Scientific classification | |
Species: | M. smithii |
Binomial name | |
Methanobrevibacter smithii Balch and Wolfe 1981 |
Is Methanobrevibacter smithii a coccobacillus?
The Methanobrevibacter smithii cell is identified as coccobacillus. Optimum temperature and pH for growth is 38°C and 6.9-7.4, respectively (4). Microbes in our colons encode enzymes that help digest complex dietary polysachharides and proteins.
What is Methanobrevibacter smithii used for?
Methanobrevibacter smithii is the predominant archaeon in the human gut. M. smithii has a cocobacillus shape. It plays an important role in the efficient digestion of polysaccharides (complex sugars) by consuming the end products of bacterial fermentation. Methanobrevibacter smithii is a single-celled microorganism from the Archaea domain.
What is the prevalence of Methanobrevibacter smithii in the US?
Methanobrevibacter smithii is highly prevalent in the human gut. Lower counts have been associated with obesity while higher amounts have been associated with anorexia. Obesity-associated gut microbiota is enriched in Lactobacillus reuteri and depleted in Bifidobacterium animalis and Methanobrevibacter smithii. [ L]
Is M smithii a methanogen?
M. smithii is a methanogen, and a hydrogenotroph that recycles the hydrogen by combining it with carbon dioxide to methane. The removal of hydrogen by M. smithii is thought to allow an increase in the extraction of energy from nutrients by shifting bacterial fermentation to more oxidized end products.
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What is the scientific name for methanogens?
Methanogens are microorganisms that produce methane as a metabolic byproduct in hypoxic conditions. They are prokaryotic and belong to the domain Archaea. All known methanogens are members of the archaeal phylum Euryarchaeota.
Where is Methanobrevibacter smithii found?
human intestineBoth Methanobrevibacter smithii and Methanosphaera stadtmanae are found in the human intestine.
What kingdom does Methanobrevibacter belong?
In taxonomy, Methanobrevibacter is a genus of the Methanobacteriaceae....MethanobrevibacterScientific classificationDomain:ArchaeaKingdom:EuryarchaeotaPhylum:Euryarchaeota8 more rows
What does high Methanobrevibacter smithii mean?
What does it mean if your Methanobrevibacter smithii result is too high? - Abundance associated with higher bacterial gene richness in the gut. - Higher amounts reported in anorexia, in contrast, one study confirmed a positive association with increased BMI and body fat in methanogen-colonized populations.
What is the main Archaeon in the human gut?
In the human gut where the microbial entities thrive more abundantly than in other parts of the human body, the archaeome consisted mostly of methane-producing archaea (methanogens), of which, members belonging to the orders Methanobacteriales (including Methanobrevibacter smithii and Methanosphaera stadtmanae) and ...
What type of cell is Methanobrevibacter Smithii?
coccobacillusCell structure, metabolism & life cycle The Methanobrevibacter smithii cell is identified as coccobacillus. Optimum temperature and pH for growth is 38°C and 6.9-7.4, respectively (4). Microbes in our colons encode enzymes that help digest complex dietary polysachharides and proteins.
What family is Methanobrevibacter in?
MethanobacteriaceaeMethanobrevibacter / FamilyIn taxonomy, the Methanobacteriaceae are a family of the Methanobacteriales. Wikipedia
Which methanogens are present in rumen of cattle?
Only eight species of ruminal methanogens have been isolated into pure cultures: Methanobacterium formicicum, Methanobacterium bryantii, Methanobrevibacter ruminantium, Methanobrevibacter millerae, Methanobrevibacter olleyae, Methanomicrobium mobile, Methanoculleus olentangyi, and Methanosarcina barkeri [13].
Where are Methanobrevibacter smithii found?
Both Methanobrevibacter smithii and Methanosphaera stadtmanae are found in the human intestine. Several archaea were found to be abundant at the site of peri-implantitis (inflammation of the soft tissue near the dental implant) ( Faveri et al., 2011 ), this suggests that archaea also contribute to the disease.
Which bacterium contains methanofuran-c?
Methanobrevibacter smithii contained methanofuran-c, which was the same as the originally characterized methanofuran except for the presence of a hydroxyl group at the 2 position of the 1,3,4,6-hexanetetracarboxylic acid moiety of the molecule.
What bacteria are used to quantitate?
Various groups have used a variety of methods to detect and sometimes quantitate special populations such as sulfate-reducing bacteria ( Desulfovibrio specifically), Bifidobacterium, lactobacilli, Methanobrevibacter smithii, various clostridia, and a mucin-degrading bacterium known as Akkermansia muciniphila.
What bacteria are in the gut microbiota?
Besides bacteria, human gut microbiota also contains Archaea, Methanobrevibacter smithii, which removes the end-product H 2 from bacterial fermentation, thus facilitating the fermentation rate and colonic energy production in the form of SCFA. It has been reported that M. smithii enhanced the degradation of dietary fructans to acetate by Bacteroides thetaiotaomicron, thereby promoting energy harvest and weight gain in germ-free (GF) mice. 41 Turnbaugh et al. (2006) 20 also demonstrated that the cecal microbiome of obese (ob/ob) mice hosted more gene tags that matched Archaea than the microbiomes of lean ( ob / + and +/+) littermates implying a higher population of the archaeon or its gene content in the obese microbiome. However, human studies revealed a different picture. Although Zhang et al. (2009) 42 detected higher number of Archaea 16 S rRNA gene copies in the obese human microbiome compared to normal-weight or post-gastric-bypass individuals using qPCR, Armougom et al. (2009), 36 also via qPCR, showed a high concentration of M. smithii in anorexic patients with a very low BMI of 12.73 on average. Although the obese group had a slightly higher concentration of M. smithii in this study, this conclusion was revised in another report by the same group to state that there was in fact a decrease in M. smithii load in the obese group, when the data was analyzed differently. 43 In this recent study with a larger samples size of 68 obese subjects and 47 controls, they demonstrated a depletion of M. smithii in the obese group. Similar results were obtained by Schwiertz et al. (2010) 35 using qPCR with a decrease in Methanobrevibacter in overweight (but metabolically healthy) persons.
What is the metagenome made of?
Over 99% of the metagenome is derived from prokaryotes (i.e., bacteria), whereas much of the remainder of the metagenome represents archaea (Qin et al., 2010 ). The archaeal component of the human microbiome is dominated by one organism, Methanobrevibacter smithii ( Eckburg et al., 2005). On the other hand, intestinal prokaryotes show considerable ...
What are the interactions between anaerobic and methanogenic bacteria?
Interactions are known to occur between anaerobic fungi and methanogenic bacteria (Mountfort et al. 1982), between anaerobic fungi and nonmethanogenic bacteria, and between anaerobic fungi and protozoa (Romulo et al. 1989; Marvin-Sikkema et al. 1990). The synergistic relationships between anaerobic fungi and methanogens have been well established; however, the benefits of such interactions to the animal host are not completely understood. Cultures of an anaerobic fungus, Neocallimastix frontalis, degraded filter paper more extensively in the presence of methanogens than in their absence ( Bauchop and Mountfort 1981 ). Fermentation shifted from the formation of electron sink products, such as lactate and H 2, to the production of more reduced end products, such as CO 2, CH 4, and acetate, in the co-culture. Mountfort and colleagues (1982) demonstrated that a monoculture of N. frontalis digested 53% of the dry-matter, whereas co-cultures of the fungus with Methanosarcina barkeri or Methanobrevibacter species converted 69% and 87%, respectively. A triculture of all three organisms converted 98% of filter paper dry weight to CO 2 and CH 4. That increased production of CO 2 and CH 4 may result in a decrease in net carbon available to the host animal.
Is Desulfovibrio fairfieldensis a polymicrobial infection?
desulfuricans together with Eggerthella lenta was indicated as the cause of a polymicrobial bloodstream infection ( Liderot, Larsson, Boräng, & Ozenci, 2010 ). A monobacterial bacteraemia resulting from a liver abscess was found to be due to D. desulfuricans ( Koyano et al., 2015 ). In the case of a prosthetic shoulder infection, D. legallii was found to be involved ( Vasoo et al., 2014 ). Notably, D. desulfuricans was apparently the cause of bacteraemia in a patient with acute cerebral infarction following aspiration bronchopneumonia and severe diarrhea; the latter may indicate that disturbed gut flora promotes Desulfovibrio infections ( Hagiwara et al., 2014). Considering the relatively long incubation times of Desulfovibrio cultures, targeted molecular approaches could be helpful for recognizing these bacteria during clinical diagnosis.
Why is Methanobrevibacter Smithii increasing?
Another explanation for the increase in Methanobrevibacter smithii is that it may help offset the increase of methane producing bacteria found in those who suffer from constipation, which commonly occurs in anorexia nervosa patients (2).
Does obese mice have more archaea?
Metagenomic studies compared gut microbial communities of genetically obese mice with lean mice and found that obese mice contain a higher representation of genes involved in polysaccharide degradation and have more archaea. Methanobrevibacter smithii affects specificity and efficiency of bacterial digestion of dietary polysaccharides, ...
Is Methanobrevibacter smithii a methanogenic organism?
Description and significance. Methanobrevibacter smithii is a methanogenic Euryarchaeote. It makes up 10% of all anaerobes in the colons of healthy adults, making it the dominant archaeon in the human gut ecosystem. Metagenomic studies compared gut microbial communities of genetically obese mice with lean mice and found ...
What does it mean if your Methanobrevibacter smithii result is too high?
What does it mean if your Methanobrevibacter smithii result is too high? - Abundance associated with higher bacterial gene richness in the gut. - Higher amounts reported in anorexia, in contrast, one study confirmed a positive association with increased BMI and body fat in methanogen-colonized populations.
Is Methanobrevibacter smithii anorexia?
Methanobrevibacter smithii is highly prevalent in the human gut. Lower counts have been associated with obesity while higher amounts have been associated with anorexia.
What is M. smithii?
We all have trillions of microorganisms living in our bodies, Chandrima explains.
Why are you studying M. smithii?
This is just one microbe in the microbiome the MAST program is looking at to better understand how these tiny organisms we live with play a role in our health.
Which bacterium contains methanofuran-c?
Methanobrevibacter smithii contained methanofuran-c, which was the same as the originally characterized methanofuran except for the presence of a hydroxyl group at the 2 position of the 1,3,4,6-hexanetetracarboxylic acid moiety of the molecule.
What are the interactions between anaerobic and methanogenic bacteria?
Interactions are known to occur between anaerobic fungi and methanogenic bacteria ( Mountfort et al. 1982 ), between anaerobic fungi and nonmethanogenic bacteria, and between anaerobic fungi and protozoa ( Romulo et al. 1989; Marvin-Sikkema et al. 1990 ). The synergistic relationships between anaerobic fungi and methanogens have been well established; however, the benefits of such interactions to the animal host are not completely understood. Cultures of an anaerobic fungus, Neocallimastix frontalis, degraded filter paper more extensively in the presence of methanogens than in their absence ( Bauchop and Mountfort 1981 ). Fermentation shifted from the formation of electron sink products, such as lactate and H 2, to the production of more reduced end products, such as CO 2, CH 4, and acetate, in the co-culture. Mountfort and colleagues (1982) demonstrated that a monoculture of N. frontalis digested 53% of the dry-matter, whereas co-cultures of the fungus with Methanosarcina barkeri or Methanobrevibacter species converted 69% and 87%, respectively. A triculture of all three organisms converted 98% of filter paper dry weight to CO 2 and CH 4. That increased production of CO 2 and CH 4 may result in a decrease in net carbon available to the host animal.
What is the gut microbiome?
The gut microbiome refers to the entire habitat associated with the gut microbiota, and incorporates biotic and abiotic factors [1]. It includes the microbes, their genetic content, and the surrounding environmental conditions.
Is Desulfovibrio fairfieldensis a polymicrobial infection?
desulfuricans together with Eggerthella lenta was indicated as the cause of a polymicrobial bloodstream infection ( Liderot, Larsson, Boräng, & Ozenci, 2010 ). A monobacterial bacteraemia resulting from a liver abscess was found to be due to D. desulfuricans ( Koyano et al., 2015 ). In the case of a prosthetic shoulder infection, D. legallii was found to be involved ( Vasoo et al., 2014 ). Notably, D. desulfuricans was apparently the cause of bacteraemia in a patient with acute cerebral infarction following aspiration bronchopneumonia and severe diarrhea; the latter may indicate that disturbed gut flora promotes Desulfovibrio infections ( Hagiwara et al., 2014 ). Considering the relatively long incubation times of Desulfovibrio cultures, targeted molecular approaches could be helpful for recognizing these bacteria during clinical diagnosis.

Overview
Importance in the human gut
The human gut microbiota consists of three main groups of hydrogen-consuming microorganisms or hydrogenotrophs: methanogens including M. smithii; various acetogenic bacteria; and sulfate-reducing bacteria. The different roles of these microorganisms are helpful in understanding how hydrogen metabolism affects the efficiency of dietary fermentation. Accumulation of hydrogen in the gut reduces the efficiency of microbial fermentation as well as the yield of energy. Methanog…
Cell wall and cell membrane compared to bacteria
The cell wall and cell membrane of Methanobrevibacter smithii determine susceptibility to antibiotics and statins. The cell wall is composed of pseudopeptidoglycan (and not peptidoglycan as in bacteria) which makes archaea resistant to lysozyme and many antibiotics that interfere with cell wall synthesis. The cell membrane consists of a lipid bilayer or monolayer, the backbone of which is composed of isoprene units that are linked to glycerol by ether bonds. In contrast, the lipi…
In anorexic patients
In 2009, the largest human study concerning obesity and gut microbiota to date was conducted. Obesity disorders are the result of an imbalance and have serious consequences such as cardiovascular disease, type 2 diabetes, and colon cancer. The gut microbiota and environment contributes to the energy imbalance because of its involvement in energy intake, conversion and storage. Culture-independent methods have shown that high proportions of methanogens can c…
M. smithii and constipation
Observational studies show a strong association between delayed intestinal transit and the production of methane. Experimental data suggest a direct inhibitory activity of methane on the colonic and ileal smooth muscle and a possible role for methane as a gasotransmitter. Statins can inhibit archaeal cell membrane biosynthesis apparently without affecting bacterial numbers as demonstrated in livestock and humans. This opens the possibility of a therapeutic intervention t…
Further reading
Bang, Corinna; Weidenbach, Katrin; Gutsmann, Thomas; Heine, Holgar; Schmitz, Ruth A. (2014). "The Intestinal Archaea Methanosphaera stadtmanae and Methanobrevibacter smithii Activate Human Dendritic Cells". PLOS ONE. 9 (6): e99411. Bibcode:2014PLoSO...999411B. doi:10.1371/journal.pone.0099411. PMC 4051749. PMID 24915454.
Kim, Gene; Deepinder, Fnu; Morales, Walter; Hwang, Laura; Weitsman, Stacy; Chang, Christopher…
External links
• Paul B. Eckburg, Paul W. Lepp, and David A. Relman Archaea and Their Potential Role in Human Disease
• Dermoumi, Heide L.; Ansorg, Rainer A.M. (2001). "Isolation and Antimicrobial Susceptibility Testing of Fecal Strains of the Archaeon Methanobrevibacter smithii". Chemotherapy. 47 (3): 177–183. doi:10.1159/000063219. PMID 11306786. S2CID 29227943.
Society and culture
- Selective and non-selective culture methods have been the standard techniques used to quantitate bacterial populations in feces; however, for various reasons, not all bacteria can be cultivated. This can result in underestimation of bacterial population sizes and microbiota diversity (O'Sullivan, 1999; Wilson and Blitchington, 1996), although cultu...
Analysis
- Once isolated, bacteria need to be identified by the use of biochemical tests (Holdeman et al., 1977), chemotaxonomic, molecular or immunological analyses (Levett, 1991), which can be time consuming and may be dependent on a particular stage of growth of the organism. This may also limit the number of fecal samples that can be used in an investigation and usually confines ident…
Function
- The human gut microbiota consists of trillions of microorganisms that are essential for preserving the integrity of the mucosal barrier. The microbiota plays an important role in the development of gut-associated lymphoid tissue (GALT), IgA secretion, and the production of antimicrobial peptides. The additional energy provided by bacterial SCFAs is estimated to represent 10% of da…
Genetics
- Thanks to modern molecular microbiology techniques [e.g. denaturing gradient gel electrophoresis (DGGE), fluorescence in situ hybridization (FISH), polymerase chain reaction (PCR), and pyrosequencing], it has been possible to accurately profile the IM. The taxonomic evaluation of the IM has led to the recognition of three distinct enterotypes: one dominated by B…
Composition
- IM studies have enabled us to quantify and qualify their composition. The first feature can be defined as richness, which describes the number of different species in a specific ecosystem, not taking into account their relative abundance; the second feature is termed evenness and indicates the relative abundance of each species in a specific ecosystem [58]. The main divisions that do…
Health
- Metabolic activity in obese children is higher than in lean ones. Despite IM composition not being significantly different between these two groups, SCFA levels measured in fecal sample were incredibly high in obese and overweight children [67]. These data suggest that high butyrate concentrations can be explained by an increased activation of butyrate-producing pathway, regu…
Research
- The IM composition of obese and overweight children after a 10-week diet and physical activity treatment showed some important differences in those who lost more than 4 kg (increased proportion of Bacteroides and Lactobacillus, decreased Bifidobacteria) vs. those who lost less than 2 kg (Clostridia and Bifidobacterium bifidum were the predominant species), suggesting th…
Clinical significance
- Another study focusing on the Firmicutes:Bacteroides ratio showed that the gut microbiota in obese children contains high levels of Lactobacillus spp. and low levels of Bacteroides vulgatus. Moreover the presence of Lactobacillus spp. was positively correlated with higher high-sensitivity CRP (hs-CRP) plasma levels. Bervoetss group recently found a correlation between Staphylococ…
Synthesis
- The main source of N2 is swallowed air. An adult ingests more than half an ounce (15 mL) of air with each swallow, the main components of which are N2 and O2, and as such, these are the main components of gastric luminal gas. CO2, H2, and CH4 are mainly produced within the gastrointestinal lumen. CO2 is generated through the interaction of hydrogen ion and bicarbonat…
Symptoms
- Excessive gastrointestinal gas may contribute to a number of symptoms including eructation, abdominal distention and bloating, excessive flatulence, and infantile colic.
Structure
- Several structurally different methanofurans are currently known with the nature of the differences residing in modifications of the side chain attached to the basic core structure of 4-[N-(γ-l-glutamyl-γ-l-glutamyl)-p-(β-aminoethyl)phenoxymethyl]-2-(aminomethyl)furan found in all methanofurans.19 The first methanofuran to be structurally characterized contained meso-1,3,4,…
Formation
- The next step in the formation of HTCA is the elongation of the carbon skeleton of oxaloglutarate by two carbon units. On the basis of the results of the isotope labeling experiments, the added carbons are expected to be derived from acetate, presumably through acetyl-CoA. This reaction is akin to the ketoacid chain elongation process that is important in the generation of fatty acid-lik…
Mechanism
- The (Z)-1-HETCA-CoA isomers would chemically racemize at C-4 and thus reduction of only the erythro isomer would produce HTCA or its CoA derivative with the correct stereochemistry at C-4 and C-5. Retaining the CoA portion of the molecule as indicated in Figure 4 would produce an activated carboxylic acid that could be used for the incorporation of HTCA into the final methan…
Classification
Description and Significance
Genome Structure
Cell Structure, Metabolism & Life Cycle
- The Methanobrevibacter smithii cell is identified as coccobacillus. Optimum temperature and pH for growth is 38°C and 6.9-7.4, respectively (4). Microbes in our colons encode enzymes that help digest complex dietary polysachharides and proteins. Bacterial fermentation of polysaccharides produces short chain fatty acids, other organic acids, alchoho...
Ecology
Interesting Feature
References