9:15 AM - 9:45 AM
★ [U04-01] Sub-seafloor methane biogeochemistry and unseen archaeal methanotrophic processes
Keywords:Sub-seafloor methane biogeochemistry, global methane cycle, Archaea, ANME (ANaerobic MEthanotroph)
Microorganisms play a central role in the global methane cycle for both production and consumption. Methanogenic archaea (methanogens) are a phylogenetically diverse group of strictly anaerobic Euryarchaeota, which grow with the enzymatic formation of methane from H2 plus CO2, acetate, and C1 compounds (e.g. methanol, methylamine) present in anaerobic environments. Kaneko et al. (2014) reported the analytical development for coenzyme factor 430, critical cofactor for biological methanogenesis and reverse-methanogenesis (occasionally), by using high performance liquid chromatography / electrospray ionization mass spectrometry (HPLC/ESI-MS/MS) on the optimized multiple reaction monitoring method during the order of 0.1-1.0 femto mol.
On the other hand, the anaerobic oxidation of methane (AOM) in marine sediments is an important microbial process in the carbon cycle and also greenhouse gas emission constraints. Since the first report of 13C-depleted lipids mediated by modern anaerobic methanotrophic archaea (ANME) consortium, the molecular carbon isotopic signatures have been recognized as an indicator of ongoing microbial methanotrophy [e.g., Hinrichs et al., 1999; Elvert et al., 1999]. Cold seep ecosystems, a biological hot spot for ANME communities, is an ideal natural laboratory for the study of methane biogeochemistry and microbial anaerobic methanotrophy driven by modern ANME communities [e.g., Knittel and Boetius, 2009 and literatures therein]. Since laboratory-based culture and isolation of ANME are currently difficult, the fate of sub-seafloor 13C-depleted methane emission is still unclear on their biosynthetic pathways during anaerobic oxidation process.
[References]
Elvert et al., 1999. Anaerobic methane oxidation associated with marine gas hydrates: superlight C-isotopes from saturated and unsaturated C-20 and C-25 irregular isoprenoids. Naturwissenschaften, 86, 295-300.
Kaneko et al., 2014. Quantitative analysis of coenzyme F430 in environmental samples: a new diagnostic tool for methanogenesis and anaerobic methane oxidation. Analytical Chemistry, 86, 3633-3638.
Knittel, K., Boetius, A., 2009. Anaerobic oxidation of methane: progress with an unknown process. Annual Review of Microbiology 63, 311-334.
Hinrichs et al., 1999. Methane-consuming archaebacteria in marine sediments. Nature, 398, 802-805.
On the other hand, the anaerobic oxidation of methane (AOM) in marine sediments is an important microbial process in the carbon cycle and also greenhouse gas emission constraints. Since the first report of 13C-depleted lipids mediated by modern anaerobic methanotrophic archaea (ANME) consortium, the molecular carbon isotopic signatures have been recognized as an indicator of ongoing microbial methanotrophy [e.g., Hinrichs et al., 1999; Elvert et al., 1999]. Cold seep ecosystems, a biological hot spot for ANME communities, is an ideal natural laboratory for the study of methane biogeochemistry and microbial anaerobic methanotrophy driven by modern ANME communities [e.g., Knittel and Boetius, 2009 and literatures therein]. Since laboratory-based culture and isolation of ANME are currently difficult, the fate of sub-seafloor 13C-depleted methane emission is still unclear on their biosynthetic pathways during anaerobic oxidation process.
[References]
Elvert et al., 1999. Anaerobic methane oxidation associated with marine gas hydrates: superlight C-isotopes from saturated and unsaturated C-20 and C-25 irregular isoprenoids. Naturwissenschaften, 86, 295-300.
Kaneko et al., 2014. Quantitative analysis of coenzyme F430 in environmental samples: a new diagnostic tool for methanogenesis and anaerobic methane oxidation. Analytical Chemistry, 86, 3633-3638.
Knittel, K., Boetius, A., 2009. Anaerobic oxidation of methane: progress with an unknown process. Annual Review of Microbiology 63, 311-334.
Hinrichs et al., 1999. Methane-consuming archaebacteria in marine sediments. Nature, 398, 802-805.