Methanogen
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ABSTRACT:
PROVIDER: PRJNA669286 | ENA |
REPOSITORIES: ENA
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Project description:We used comparative transcriptomics to explore cellular responses to growth on pyrite (FeS2) or aqueous iron (Fe(II)) and sulfur (cysteine or sulfide). Transcriptomic data from wild type M. barkeri identified subset of genes that was significantly upregulated during grown on FeS2 versus ferrous iron and cysteine or sulfide. Several of these genes, including a membrane-bound hydrolase, alpha-keto reductases, and flavin mononucleotide-dependent flavodoxin reductases were highly conserved among known FeS2-reducing methanogens and were located in a single gene cassette. Putative enzymatically catalyzed mechanisms of FeS2 reduction are proposed for each of these enzyme systems to guide their future biochemical and biophysical study. Transcriptomic data from wild type M. barkeri identified subset of genes that was significantly upregulated during grown on FeS2 versus ferrous iron and cysteine or sulfide. Several of these genes, including a membrane-bound hydrolase, alpha-keto reductases, and flavin mononucleotide-dependent flavodoxin reductases were highly conserved among known FeS2-reducing methanogens and were located in a single gene cassette. Putative enzymatically catalyzed mechanisms of FeS2 reduction are proposed for each of these enzyme systems to guide their future biochemical and biophysical study.
2022-03-13 | GSE168895 | GEO
Project description:Methanogens were recently shown to reduce pyrite (FeS2) generating aqueous iron-sulfide (FeS(aq)) clusters that are likely assimilated as a source of Fe and S. Here, we compare the phenotype of Methanococcus voltae when grown with FeS2 or ferrous iron (Fe(II)) and sulfide (HS-). Differential proteomic analyses showed similar expression of core methanogenesis enzymes, indicating that Fe and S source does not substantively alter the energy metabolism of cells. However, a homolog of the Fe(II) transporter FeoB and its transcriptional regulator DtxR were up-expressed in FeS2 grown cells, indicating that cells sense Fe(II) limitation. Two homologs of IssA, a protein putatively involved in coordinating thioferrate nanoparticles, were also up-expressed in FeS2 grown cells. We interpret these data to indicate that DtxR cannot sense Fe(II) and therefore cannot down-regulate FeoB. We suggest this is due to the transport of Fe(II) complexed with sulfide (FeS(aq)) leading to excess Fe that is sequestered by IssA as a thioferrate-like species. This model provides a framework for the design of targeted experiments aimed at further characterizing Fe acquisition and homeostasis in M. voltae and other methanogens.
2021-07-07 | PXD024933 | Pride
Project description:Methanogens inhabit euxinic (sulfide-rich) or ferruginous (iron-rich) environments that promote the precipitation of transition metals as metal sulfides, such as pyrite, reducing metal or sulfur availability. Such environments have been common throughout Earth’s history raising the question as to how anaerobes obtain(ed) these elements for the synthesis of enzyme cofactors. Here, we show a methanogen can synthesize molybdenum nitrogenase metallocofactors from pyrite as the source of iron and sulfur, enabling nitrogen fixation. Pyrite-grown, nitrogen-fixing cells grow faster and require 25-fold less molybdenum than cells grown under euxinic conditions. Growth yields are 3 to 8 times higher in cultures grown under ferruginous relative to euxinic conditions. Physiological, transcriptomic, and geochemical data indicate these observations are due to sulfide-promoted metal limitation, in particular molybdenum. These findings suggest that molybdenum nitrogenase may have originated in a ferruginous environment that titrated sulfide to form pyrite, facilitating the availability of sufficient iron, sulfur, and molybdenum for cofactor biosynthesis.
2023-05-01 | GSE216895 | GEO
Project description:Methylated sulfur compounds, including dimethylsulfide (DMS), methylmercaptopropionic acid (MMPA) and methylsulfide (MeSH), are well-documented to play roles in global sulfur cycle and climate homeostasis, yet the molecular mechanisms of how they are metabolized by methanogens remain largely uncharacterized. Here, using high-throughtput sequencing of RNA (RNA-seq), we gained insight into how methanogens respond to methylated sulfur compounds at the transcriptional level.
2015-02-18 | GSE64349 | GEO
Project description:Methylated sulfur compounds, including dimethylsulfide (DMS), methylmercaptopropionic acid (MMPA) and methylsulfide (MeSH), are well-documented to play roles in global sulfur cycle and climate homeostasis, yet the molecular mechanisms of how they are metabolized by methanogens remain largely uncharacterized. Here, using high-throughtput sequencing of RNA (RNA-seq), we gained insight into how methanogens respond to methylated sulfur compounds at the transcriptional level. The mRNA from wild-type of Methanosarcina acetivorans C2A grown on methylated sulfur compounds were harvested, sequenced and mapped to the genome. Then, we compared RNA-seq profiles to that grown on MeOH in search of unque genes.
2015-02-18 | E-GEOD-64349 | biostudies-arrayexpress
Project description:Origanum oil (ORO), garlic oil (GAO), and peppermint oil (PEO) were shown to effectively lower methane production, decrease abundance of methanogens, and change abundances of several bacterial populations important to feed digestion in vitro. In this study, the impact of these essential oils (EOs, at 0.50 g/L), on the rumen bacterial community composition was further examined using the recently developed RumenBactArray.
2014-10-23 | GSE62624 | GEO
Project description:Methylmercury (MeHg), a neurotoxic substance that accumulates in aquatic food chains and poses a risk to human health, is synthesized by anaerobic microorganisms in the environment. To date, mercury (Hg) methylation has been attributed to sulfate- and iron-reducing bacteria (SRB and IRB, respectively). Here we report that a methanogen, Methanospirillum hungatei JF-1, methylated Hg in a sulfide-free medium at comparable rates, but with higher yields, than those observed for some SRB and IRB. Phylogenetic analyses showed that the concatenated orthologs of the Hg methylation proteins HgcA and HgcB from M. hungatei are closely related to those from known SRB and IRB methylators and that they cluster together with proteins from eight other methanogens, suggesting that these methanogens may also methylate Hg. Because all nine methanogens with HgcA and HgcB orthologs belong to the class Methanomicrobia, constituting the late-evolving methanogenic lineage, methanogenic Hg methylation could not be considered an ancient metabolic trait. Our results identify methanogens as a new guild of Hg-methylating microbes with a potentially important role in mineral-poor (sulfate- and iron-limited) anoxic freshwater environments.
| S-EPMC3811210 | biostudies-literature