Kolb, S; Cabrera, A; Kammann, C; Kämpfer, P; Conrad, R; Jäckel, U: Quantitative Impact of CO2 enriched Atmosphere on Abundances of Methanotrophic Bacteria in a Meadow Soil, Biology and Fertility of Soils, 41(5), 337-342 (2005), doi:doi 10.1007/s00374-005-0842-y | |
Abstract: In the Giessen free air carbon dioxide enrichment (GiFACE) experiment three years of carbon dioxide (CO2) enrichment lead to decreased methane (CH4) uptake rates of the investigated meadow soil. In soils CH4 oxidation is mainly conducted by methanotrophic bacteria. In the present study abundances of methanotrophic bacteria and total Bacteria in soil samples from the GiFACE experiment were quantified by applying pmoA- and 16S rRNA gene-targeted real-time PCR and fluorescence in situ hybridisation (FISH). Methanotrophic bacteria of the Methylosinus group (Alphaproteobacteria) and the Methylobacter/Methylosarcina group (Gammaproteobacteria) were detectable by real-time PCR as well as by FISH. Both quantitative analytical aproaches revealed, that abundances either of Bacteria as well as of methanotrophic bacteria in soil samples from sites under CO2 enriched atmosphere were decreased. Compared to ambient site only 46% and 30.5% of methanotrophic bacteria and 38 % and 63.2% of total bacterial cell numbers could be detected under CO2 enriched atmosphere by FISH and real-time PCR, respectively. These results suggest that significantly decreased abundances of methanotrophic bacteria could explain reduced CH4 uptake rates. |