Candidatus "Methylomirabilis oxyfera" is a candidate species of Gram-negative bacteria belonging to the NC10 phylum, characterized for its capacity to couple anaerobic methane oxidation with nitrite reduction in anoxic environments.[3][4] To acquire oxygen for methane oxidation, M. oxyfera utilizes an intra-aerobic pathway through the reduction of nitrite (NO2) to dinitrogen (N2) and oxygen.[5]

Methylomirabilis oxyfera
Methylomirabilis sp.. Scale bar; 200 nm.[1]
Scientific classification
Domain:
Phylum:
Class:
"Methylomirabilacaea"[2]
Order:
"Methylomirabilales"[2]
Family:
"Methylomirabilaceae"
Genus:
"Ca. Methylomirabilis"
Binomial name
"Ca. Methylomirabilis oxygeniifera"
corrig. Ettwig et al. 2010

Enrichment

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Enriched Ca. "M. oxyfera" cells have been identified as primarily having a unique polygonal cell shape through the use of electron microscopy techniques. Unlike methanotrophic Pseudomonadota, Ca. "M. oxyfera" cells lack intracytoplasmic membranes when grown under laboratory conditions.[6] The optimum growth ranges for Ca. "M. oxyfera" is between pH 7-8 and 25-30 °C.[3] Ca. "M. oxyfera"cell envelopes are Gram-negative and are generally 0.25–0.5 μm in diameter and 0.8–1.1 μm in length.[3][6]

Methane oxidation

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Ca. "M. oxyfera" has the capacity to disproportionate nitric oxide into oxygen and nitrogen gas. This intermediate oxygen is then used in the oxidation of methane into carbon dioxide.[3][5]

Overall reactions

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Nitrogen oxide dismutation:

2 NO2 → 2 NO → N2 + O2

Methane oxidation:

O2 + CH4 → CH3OH → CO2

Environmental significance

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Ca. "M. oxyfera" has been identified in several environments including rice paddy soil in China,[7] multiple river and lake sediments,[8] and wastewater sludge in The Netherlands.[9] Ca. "M. oxyfera" is predicted to inhabit environments with high concentrations of nitrogen and methane, near boundaries that separate oxic and anoxic zones. It is suggested that Ca. "M. oxyfera" and similar organisms contribute to the global carbon and nitrogen cycles. These organisms may also play a role in reducing the nutrient loads within freshwater ecosystems that have been contaminated with fertilizers.[8] Nitrites are usually undesirable in the environment, can be detrimental to human health, and can lead to eutrophication of aquatic ecosystems and algal blooms.[10][11] Meanwhile methane is a potent greenhouse gas that has a stronger greenhouse potential per molecule than carbon dioxide.[12] The presence of organisms like M. oxyfera can therefore be beneficial in many environments and might be used for bioremediation or sewage treatment in the future.

See also

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References

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  1. ^ Gambelli, Lavinia; Cremers, Geert; Mesman, Rob; Guerrero, Simon; Dutilh, Bas E.; Jetten, Mike S. M.; Op den Camp, Huub J. M.; van Niftrik, Laura (8 November 2016). "Ultrastructure and Viral Metagenome of Bacteriophages from an Anaerobic Methane Oxidizing Methylomirabilis Bioreactor Enrichment Culture". Frontiers in Microbiology. 7: 1740. doi:10.3389/fmicb.2016.01740. PMC 5099504. PMID 27877158.
  2. ^ a b Cabrol, Léa; Thalasso, Frédéric; Gandois, Laure; Sepulveda-Jauregui, Armando; Martinez-Cruz, Karla; Teisserenc, Roman; Tananaev, Nikita; Tveit, Alexander; Svenning, Mette M.; Barret, Maialen (September 2020). "Anaerobic oxidation of methane and associated microbiome in anoxic water of Northwestern Siberian lakes". Science of the Total Environment. 736: 139588. Bibcode:2020ScTEn.73639588C. doi:10.1016/j.scitotenv.2020.139588. hdl:10037/19970. PMID 32497884.
  3. ^ a b c d Ettwig, Katharina F.; Butler, Margaret K.; Le Paslier, Denis; Pelletier, Eric; Mangenot, Sophie; Kuypers, Marcel M. M.; Schreiber, Frank; Dutilh, Bas E.; Zedelius, Johannes; de Beer, Dirk; Gloerich, Jolein; Wessels, Hans J. C. T.; van Alen, Theo; Luesken, Francisca; Wu, Ming L.; van de Pas-Schoonen, Katinka T.; Op den Camp, Huub J. M.; Janssen-Megens, Eva M.; Francoijs, Kees-Jan; Stunnenberg, Henk; Weissenbach, Jean; Jetten, Mike S. M.; Strous, Marc (March 2010). "Nitrite-driven anaerobic methane oxidation by oxygenic bacteria". Nature. 464 (7288): 543–548. Bibcode:2010Natur.464..543E. doi:10.1038/nature08883. hdl:2066/84284. PMID 20336137. S2CID 205220000.
  4. ^ Haroon, Mohamed F.; Hu, Shihu; Shi, Ying; Imelfort, Michael; Keller, Jurg; Hugenholtz, Philip; Yuan, Zhiguo; Tyson, Gene W. (29 August 2013). "Anaerobic oxidation of methane coupled to nitrate reduction in a novel archaeal lineage". Nature. 500 (7464): 567–570. Bibcode:2013Natur.500..567H. doi:10.1038/nature12375. PMID 23892779. S2CID 4368118.
  5. ^ a b Wu, Ming L.; Ettwig, Katharina F.; Jetten, Mike S.M.; Strous, Marc; Keltjens, Jan T.; Niftrik, Laura van (February 2011). "A new intra-aerobic metabolism in the nitrite-dependent anaerobic methane-oxidizing bacterium Candidatus 'Methylomirabilis oxyfera'". Biochemical Society Transactions. 39 (1): 243–248. doi:10.1042/BST0390243. hdl:2066/91512. PMID 21265781.
  6. ^ a b Wu, Ming L.; van Teeseling, Muriel C. F.; Willems, Marieke J. R.; van Donselaar, Elly G.; Klingl, Andreas; Rachel, Reinhard; Geerts, Willie J. C.; Jetten, Mike S. M.; Strous, Marc; van Niftrik, Laura (15 January 2012). "Ultrastructure of the Denitrifying Methanotroph 'Candidatus Methylomirabilis oxyfera,' a Novel Polygon-Shaped Bacterium". Journal of Bacteriology. 194 (2): 284–291. doi:10.1128/JB.05816-11. PMC 3256638. PMID 22020652.
  7. ^ He, Zhanfei; Cai, Chaoyang; Wang, Jiaqi; Xu, Xinhua; Zheng, Ping; Jetten, Mike S. M.; Hu, Baolan (September 2016). "A novel denitrifying methanotroph of the NC10 phylum and its microcolony". Scientific Reports. 6 (1): 32241. Bibcode:2016NatSR...632241H. doi:10.1038/srep32241. PMC 5007514. PMID 27582299.
  8. ^ a b Shen, Li-Dong; He, Zhan-Fei; Zhu, Qun; Chen, Dong-Qing; Lou, Li-Ping; Xu, Xiang-Yang; Zheng, Ping; Hu, Bao-Lan (2012). "Microbiology, ecology, and application of the nitrite-dependent anaerobic methane oxidation process". Frontiers in Microbiology. 3: 269. doi:10.3389/fmicb.2012.00269. PMC 3408237. PMID 22905032.
  9. ^ Luesken, Francisca A.; van Alen, Theo A.; van der Biezen, Erwin; Frijters, Carla; Toonen, Ger; Kampman, Christel; Hendrickx, Tim L. G.; Zeeman, Grietje; Temmink, Hardy; Strous, Marc; Op den Camp, Huub J. M.; Jetten, Mike S. M. (November 2011). "Diversity and enrichment of nitrite-dependent anaerobic methane oxidizing bacteria from wastewater sludge". Applied Microbiology and Biotechnology. 92 (4): 845–854. doi:10.1007/s00253-011-3361-9. PMC 3198195. PMID 21667086.
  10. ^ "Nitrite pollution puts warming waters at risk". 2 May 2017.
  11. ^ Grout, Leah; Chambers, Tim; Hales, Simon; Prickett, Marnie; Baker, Michael G.; Wilson, Nick (20 January 2023). "The potential human health hazard of nitrates in drinking water: a media discourse analysis in a high-income country". Environmental Health. 22 (1): 9. Bibcode:2023EnvHe..22....9G. doi:10.1186/s12940-023-00960-5. PMC 9851889. PMID 36658626.
  12. ^ "Methane | Vital Signs".