TY - JOUR A1 - Noll, Matthias A1 - Klose, M. A1 - Conrad, R. T1 - Effect of temperature change on the composition of the bacterial and archaeal community potentially involved in the turnover of acetate and propionate in methanogenic rice field soil JF - FEMS microbiology ecology N2 - The microbial community structure was investigated together with the path of methane production in Italian rice field soil incubated at moderate (35 °C) and high (45 °C) temperature using terminal restriction fragment length polymorphism and stable isotope fractionation. The structure of both the archaeal and bacterial communities differed at 35 °C compared with 45 °C, and acetoclastic and hydrogenotrophic methanogenesis dominated, respectively. Changing the incubation of the 45 °C soil to different temperatures (25, 30, 35, 40, 45, 50 °C) resulted in a dynamic change of both microbial community structure and stable isotope fractionation. In all treatments, acetate first accumulated and then decreased. Propionate was also transiently produced and consumed. It is noteworthy that acetate was also consumed at thermophilic conditions, although archaeal community composition and stable isotope fractionation indicated that acetoclastic methanogenesis did not operate. Instead, acetate must have been consumed by syntrophic acetate oxidizers. The transient accumulation and subsequent consumption of acetate at thermophilic conditions was specifically paralleled by terminal restriction fragments characteristic for clostridial cluster I, whereas those of clostridial clusters I and III, Acidaminococcaceae and Heliobacteraceae, paralleled the thermophilic turnover of both acetate and propionate. KW - Syntrophic acetate oxidation KW - Thermophilic microbial community KW - Terminal restriction fragment length polymorphism KW - Bacteria KW - Archaea KW - Structure and function KW - Methanogenic archael community KW - Temperature shift PY - 2010 DO - https://doi.org/10.1111/j.1574-6941.2010.00883.x SN - 0168-6496 SN - 1574-6941 VL - 73 IS - 2 SP - 215 EP - 225 PB - Blackwell Publishing CY - Oxford AN - OPUS4-21671 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Conrad, R. A1 - Klose, M. A1 - Noll, Matthias T1 - Functional and structural response of the methanogenic microbial community in rice field soil to temperature change JF - Environmental microbiology N2 - The microbial community in anoxic rice field soil produces CH4 over a wide temperature range up to 55°C. However, at temperatures higher than about 40°C, the methanogenic path changes from CH4 production by hydrogenotrophic plus acetoclastic methanogenesis to exclusively hydrogenotrophic methanogenesis and simultaneously, the methanogenic community consisting of Methanosarcinaceae, Methanoseataceae, Methanomicrobiales, Methanobacteriales and Rice Cluster I (RC-1) changes to almost complete dominance of RC-1. We studied changes in structure and function of the methanogenic community with temperature to see whether microbial members of the community were lost or their function impaired by exposure to high temperature. We characterized the function of the community by the path of CH4 production measuring δ13C in CH4 and CO2 and calculating the apparent fractionation factor (αapp) and the structure of the community by analysis of the terminal restriction fragment length polymorphism (T-RFLP) of the microbial 16S rRNA genes. Shift of the temperature from 45°C to 35°C resulted in a corresponding shift of function and structure, especially when some 35°C soil was added to the 45°C soil. The bacterial community (T-RFLP patterns), which was much more diverse than the archaeal community, changed in a similar manner upon temperature shift. Incubation of a mixture of 35°C and 50°C pre-incubated methanogenic rice field soil at different temperatures resulted in functionally and structurally well-defined communities. Although function changed from a mixture of acetoclastic and hydrogenotrophic methanogenesis to exclusively hydrogenotrophic methanogenesis over a rather narrow temperature range of 42-46°C, each of these temperatures also resulted in only one characteristic function and structure. Our study showed that temperature conditions defined structure and function of the methanogenic microbial community. KW - Structure and function KW - Methanogenic archaeal community KW - Temperature shift PY - 2009 DO - https://doi.org/10.1111/j.1462-2920.2009.01909.x SN - 1462-2912 SN - 1462-2920 VL - 11 IS - 7 SP - 1844 EP - 1853 PB - Blackwell Science CY - Oxford AN - OPUS4-19596 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Conrad, R. A1 - Klose, M. A1 - Noll, Matthias A1 - Kemnitz, D. A1 - Bodelier, P.L.E. T1 - Soil type links microbial colonization of rice roots to methane emission JF - Global change biology N2 - Most of the methane (CH4) emission from rice fields is derived from plant photosynthates, which are converted to CH4. Rice cluster I (RC-1) archaea colonizing the rhizosphere were found to be the methanogens responsible for this process. Hence, RC-1 methanogens seem to play a crucial role in emission of the greenhouse gas CH4. We determined the community composition and activity of methanogens colonizing the roots of eight different rice cultivars after growth on both Italian rice soil and river bank soil, which contained different communities of methanogenic archaea. The community composition was analyzed by terminal restriction fragment length polymorphism and cloning/sequencing of the archaeal 16S rRNA gene and the mcrA gene coding for a subunit of the methyl coenzyme M reductase. When grown on rice field soil, the methanogenic community of the different rice cultivars was always dominated by RC-1 methanogens. In contrast, roots were colonized by Methanomicrobiales when grown on river bank soil, in which RC-1 methanogens were initially not detectable. Roots colonized with Methanomicrobiales compared with RC-1 exhibited lower CH4 production and CH4 emission rates. The results show that the type of methanogens colonizing rice roots has a potentially important impact on the global CH4 cycle. KW - Gene sequence KW - Methane emission KW - Methanomicrobiales KW - Methyl coenzyme M reductase KW - Ribosomal RNA KW - Rice cluster I KW - Rice cultivar KW - Rice field soil KW - Rice root KW - Terminal restriction fragment length polymorphism PY - 2008 DO - https://doi.org/10.1111/j.1365-2486.2007.01516.x SN - 1354-1013 SN - 1365-2486 VL - 14 IS - 3 SP - 657 EP - 669 PB - Blackwell Science CY - Oxford AN - OPUS4-16517 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -