Open AccessField‐scale labelling and activity quantification of methane‐oxidizing bacteria in a landfill‐cover soil
Author(s) -
Henneberger Ruth,
Chiri Eleonora,
Blees Jan,
Niemann Helge,
Lehmann Moritz F.,
Schroth Martin H.
Publication year - 2013
Publication title -
fems microbiology ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.377
H-Index - 155
eISSN - 1574-6941
pISSN - 0168-6496
DOI - 10.1111/j.1574-6941.2012.01477.x
Subject(s) - dominance (genetics) , biology , anaerobic oxidation of methane , environmental chemistry , soil water , oxidizing agent , methane , stable isotope probing , microbial population biology , δ13c , bacteria , stable isotope ratio , chemistry , biochemistry , ecology , microorganism , genetics , organic chemistry , gene , physics , quantum mechanics
Aerobic methane‐oxidizing bacteria ( MOB ) play an important role in soils, mitigating emissions of the greenhouse gas methane ( CH 4 ) to the atmosphere. Here, we combined stable isotope probing on MOB ‐specific phospholipid fatty acids ( PLFA ‐ SIP ) with field‐based gas push‐pull tests ( GPPT s). This novel approach ( SIP ‐ GPPT ) was tested in a landfill‐cover soil at four locations with different MOB activity. Potential oxidation rates derived from regular‐ and SIP ‐ GPPT s agreed well and ranged from 0.2 to 52.8 mmol CH 4 (L soil air) −1 day −1 . PLFA profiles of soil extracts mainly contained C 14 to C 18 fatty acids ( FA s), with a dominance of C 16 FA s. Uptake of 13 C into MOB biomass during SIP ‐ GPPT s was clearly indicated by increased δ 13 C values (up to c . 1500‰) of MOB ‐characteristic FA s. In addition, 13 C incorporation increased with CH 4 oxidation rates. In general, FA s C 14:0 , C 16:1ω8 , C 16:1ω7 and C 16:1ω6 (type I MOB ) showed highest 13 C incorporation, while substantial 13 C incorporation into FA s C 18:1ω8 and C 18:1ω7 (type II MOB ) was only observed at high‐activity locations. Our findings demonstrate the applicability of the SIP ‐ GPPT approach for in situ quantification of potential CH 4 oxidation rates and simultaneous labelling of active MOB , suggesting a dominance of type I MOB over type II MOB in the CH 4 ‐oxidizing community in this landfill‐cover soil.