TY - JOUR
T1 - Field-scale labelling and activity quantification of methane-oxidizing bacteria in a landfill-cover soil
AU - Henneberger, Ruth
AU - Chiri, Eleonora
AU - Blees, Jan
AU - Niemann, Helge
AU - Lehmann, Moritz F.
AU - Schroth, Martin H.
PY - 2013/2/1
Y1 - 2013/2/1
N2 - Aerobic methane-oxidizing bacteria (MOB) play an important role in soils, mitigating emissions of the greenhouse gas methane (CH4) to the atmosphere. Here, we combined stable isotope probing on MOB-specific phospholipid fatty acids (PLFA-SIP) with field-based gas push-pull tests (GPPTs). 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-GPPTs agreed well and ranged from 0.2 to 52.8 mmol CH4 (L soil air)-1 day-1. PLFA profiles of soil extracts mainly contained C14 to C18 fatty acids (FAs), with a dominance of C16 FAs. Uptake of 13C into MOB biomass during SIP-GPPTs was clearly indicated by increased δ13C values (up to c. 1500‰) of MOB-characteristic FAs. In addition, 13C incorporation increased with CH4 oxidation rates. In general, FAs C14:0, C16:1ω8, C16:1ω7 and C16:1ω6 (type I MOB) showed highest 13C incorporation, while substantial 13C incorporation into FAs C18:1ω8 and C18:1ω7 (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 CH4 oxidation rates and simultaneous labelling of active MOB, suggesting a dominance of type I MOB over type II MOB in the CH4-oxidizing community in this landfill-cover soil.
AB - Aerobic methane-oxidizing bacteria (MOB) play an important role in soils, mitigating emissions of the greenhouse gas methane (CH4) to the atmosphere. Here, we combined stable isotope probing on MOB-specific phospholipid fatty acids (PLFA-SIP) with field-based gas push-pull tests (GPPTs). 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-GPPTs agreed well and ranged from 0.2 to 52.8 mmol CH4 (L soil air)-1 day-1. PLFA profiles of soil extracts mainly contained C14 to C18 fatty acids (FAs), with a dominance of C16 FAs. Uptake of 13C into MOB biomass during SIP-GPPTs was clearly indicated by increased δ13C values (up to c. 1500‰) of MOB-characteristic FAs. In addition, 13C incorporation increased with CH4 oxidation rates. In general, FAs C14:0, C16:1ω8, C16:1ω7 and C16:1ω6 (type I MOB) showed highest 13C incorporation, while substantial 13C incorporation into FAs C18:1ω8 and C18:1ω7 (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 CH4 oxidation rates and simultaneous labelling of active MOB, suggesting a dominance of type I MOB over type II MOB in the CH4-oxidizing community in this landfill-cover soil.
KW - Gas push-pull test
KW - in situ labelling
KW - Methanotrophs
KW - Phospholipid ester-linked fatty acids
KW - Stable isotope probing
UR - http://www.scopus.com/inward/record.url?scp=84871971451&partnerID=8YFLogxK
U2 - 10.1111/j.1574-6941.2012.01477.x
DO - 10.1111/j.1574-6941.2012.01477.x
M3 - Article
C2 - 22928887
AN - SCOPUS:84871971451
VL - 83
SP - 392
EP - 401
JO - FEMS Microbiology Ecology
JF - FEMS Microbiology Ecology
SN - 0168-6496
IS - 2
ER -