00587nas a2200169   4500008004100000022001400041245010100055210006900156300001000225490000700235100002000242700002200262700001700284700002200301700002800323856006600351       2024                        eng d  a2150-892500aBiological and physical controls of methane uptake in grassland soils across the US Great Plains0 aBiological and physical controls of methane uptake in grassland   ae49550 v151 aKoyama, Akihiro1 aJohnson, Nels, G.1 aBrewer, Paul1 aWebb, Colleen, T.1 avon Fischer, Joseph, C.  uhttps://esajournals.onlinelibrary.wiley.com/toc/21508925/15/902820nas a2200229   4500008004100000022001300041245010300054210006900157300001200226490000700238520203300245653002002278653003902298653002702337653003202364100002002396700002002416700002202436700001702458700002802475856008702503       2016                        eng d  a0038071700aCo-variation in methanotroph community composition and activity in three temperate grassland soils0 aCovariation in methanotroph community composition and activity i  a78 - 860 v953 a<p>Methane is a potent greenhouse gas, and the uptake of methane by methanotrophic bacteria in oxic, well-drained soils is a key global sink. Field studies at the ecosystem scale have observed significant temporal and spatial variation in methane uptake rates, but there is considerable uncertainty about the roles of abiotic and biotic factors, including methanotroph community composition, in structuring these patterns. Here, we present an analysis of Michaelis&ndash;Menten kinetics of methane uptake in soils collected from three North American temperate grassland sites of differing soil moisture regimes and their methanotroph community composition. The three sites were Konza Prairie in Kansas, Shortgrass Steppe in Colorado and Sevilleta in New Mexico with mean annual precipitation of 835, 320 and 244 mm, respectively. Michaelis&ndash;Menten kinetics and methanotroph community were assessed via lab incubation and pmoA-based phylogeny, respectively. Across the precipitation gradient we observed distinct variation in Michaelis&ndash;Menten kinetics and methanotroph community composition. Both KM and VMax values of the Michaelis&ndash;Menten kinetics followed the trend of the mean annual precipitation (Konza Prairie &gt; Shortgrass Steppe &gt; Sevilleta). The observed six methanotroph clades were all within the γ-proteobacteria division, and included two novel clades found in Shortgrass Steppe and Sevilleta. The methanotroph communities were dominated by Methylococcus spp, JR2 clade, and USC gamma, in Konza Prairie, Shortgrass Steppe and Sevilleta soils, respectively. The distinct differences in the community composition among the three sites may help explain the functional variation of upland methanotrophy observed in KM. Taken together, the coincident differences in Michaelis&ndash;Menten kinetics we observed suggest that methanotroph community composition can be important for CH4 uptake in controlled environments, potentially playing a role in the variation in methane uptake in the fields.</p>10aGrassland soils10aMethanotroph community composition10aMethanotroph phylogeny10aMichaelis–Menten kinetics1 aJudd, Craig, R.1 aKoyama, Akihiro1 aSimmons, Mark, P.1 aBrewer, Paul1 avon Fischer, Joseph, C.  uhttps://www.sciencedirect.com/science/article/abs/pii/S0038071715004460?via%3Dihub