Nonbacterial biotic methanogenesis, possible mechanisms and significance

Eszter Tuboly, András Mészáros, M. Borós

Research output: Chapter in Book/Report/Conference proceedingChapter

2 Citations (Scopus)


Methane was earlier commonly thought to be produced in the gastrointestinal tract exclusively by methanogenic bacterial fermentation, under strictly anaerobic conditions. This notion was challenged when various in vitro and in vivo studies revealed the possibility of nonmicrobial methane formation in the mitochondria and eukaryote cells in both plants and animals. The biological role of this process in the mammalian physiology is largely unmapped, but it is conceivable that the formation and constant buildup of reactive oxygen species in the mitochondria are integral parts of a broader system. The initial in vitro studies led to the proposal that a continuous lack of the electron acceptor oxygen will maintain an elevated mitochondrial NADH/NAD+ ratio, causing reductive stress. Electrophilic methyl groups bound to positivelycharged nitrogen moieties such as those in phosphatidylcholine molecules may potentially act as substitute electron acceptors as a consequence of which methane may be liberated. Thus, priming during hypoxia occurs as a progressive process involving depressed electron transport, the loss of cytochrome c and antioxidants, and the triggering of methane release during the abnormal formation of ROS induced by reoxygenation or reperfusion. It is therefore possible that the formation and emission of methane in mammals may be connected with hypoxic events leading to, or associated with a mitochondrial dysfunction. This also points to a role of methane as an alarm signal for the development of mitochondrial responses under hypoxic conditions, and accordingly it may be a biomarker for the diagnosis of such events.

Original languageEnglish
Title of host publicationMethanogenesis: Biochemistry, Ecological Functions, Natural and Engineered Environments
PublisherNova Science Publishers, Inc.
Number of pages32
ISBN (Print)9781633215979, 9781633215672
Publication statusPublished - Jul 1 2014



  • Biotic
  • Methane
  • Methanogenesis
  • Non bacterial

ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)

Cite this

Tuboly, E., Mészáros, A., & Borós, M. (2014). Nonbacterial biotic methanogenesis, possible mechanisms and significance. In Methanogenesis: Biochemistry, Ecological Functions, Natural and Engineered Environments (pp. 19-50). Nova Science Publishers, Inc..