scholarly journals Phosphate Inhibits Acetotrophic Methanogenesis on Rice Roots

2000 ◽  
Vol 66 (2) ◽  
pp. 828-831 ◽  
Author(s):  
Ralf Conrad ◽  
Melanie Klose ◽  
Peter Claus
Keyword(s):  
Carbon Isotope ◽  
Isotope Fractionation ◽  
Stable Carbon Isotope ◽  
Stable Carbon ◽  
Methyl Fluoride ◽  
Carbon Isotope Fractionation ◽  
Rice Roots ◽  
Stable Carbon Isotope Fractionation

ABSTRACT The contribution of acetate- and H2/CO2-dependent methanogenesis to total CH4 production was determined in excised washed rice roots by radiolabeling, methyl fluoride inhibition, and stable carbon isotope fractionation. Addition of ≥20 mM phosphate inhibited methanogenesis, which then was exclusively from H2/CO2. Otherwise, acetate contributed about 50 to 60% of the total methanogenesis, demonstrating that phosphate specifically inhibited acetotrophic methanogens on rice roots.

scholarly journals Stable Carbon Isotope Fractionation by Methylotrophic Methanogenic Archaea

2012 ◽  
Vol 78 (21) ◽  
pp. 7596-7602 ◽  
Author(s):  
Jörn Penger ◽  
Ralf Conrad ◽  
Martin Blaser
Keyword(s):  
Carbon Isotope ◽  
Isotope Fractionation ◽  
Stable Carbon Isotope ◽  
Methanogenic Archaea ◽  
Methanosarcina Barkeri ◽  
Stable Carbon ◽  
Methyl Fluoride ◽  
Content Type ◽  
Carbon Isotope Fractionation ◽  
Stable Carbon Isotope Fractionation

ABSTRACTIn natural environments methane is usually produced by aceticlastic and hydrogenotrophic methanogenic archaea. However, some methanogens can use C1compounds such as methanol as the substrate. To determine the contributions of individual substrates to methane production, the stable-isotope values of the substrates and the released methane are often used. Additional information can be obtained by using selective inhibitors (e.g., methyl fluoride, a selective inhibitor of acetoclastic methanogenesis). We studied stable carbon isotope fractionation during the conversion of methanol to methane inMethanosarcina acetivorans,Methanosarcina barkeri, andMethanolobus zinderiand generally found large fractionation factors (−83‰ to −72‰). We further tested whether methyl fluoride impairs methylotrophic methanogenesis. Our experiments showed that even though a slight inhibition occurred, the carbon isotope fractionation was not affected. Therefore, the production of isotopically light methane observed in the presence of methyl fluoride may be due to the strong fractionation by methylotrophic methanogens and not only by hydrogenotrophic methanogens as previously assumed.

Stable Carbon Isotope Fractionation of 1,2-Dichloropropane during Dichloroelimination byDehalococcoidesPopulations

2009 ◽  
Vol 43 (18) ◽  
pp. 6915-6919 ◽  
Author(s):  
Kelly E. Fletcher ◽  
Frank E. Löffler ◽  
Hans-Hermann Richnow ◽  
Ivonne Nijenhuis
Keyword(s):  
Carbon Isotope ◽  
Isotope Fractionation ◽  
Stable Carbon Isotope ◽  
Stable Carbon ◽  
Carbon Isotope Fractionation ◽  
Stable Carbon Isotope Fractionation
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