Altered carbon turnover processes and microbiomes in soils under long-term extremely high CO2 exposure

Abstract

* There is only limited understanding of the impact of high p(CO 2 ) on soil biomes. We have studied a floodplain wetland where long-term emanations of temperate volcanic CO 2 (mofettes) are associated with accumulation of carbon from the Earth's mantle. With an integrated approach using isotope geochemistry, soil activity measurements and multi-omics analyses, we demonstrate that high (nearly pure) CO 2 concentrations have strongly affected pathways of carbon production and decomposition and therefore carbon turnover. In particular, a promotion of dark CO 2 fixation significantly increased the input of geogenic carbon in the mofette when compared to a reference wetland soil exposed to normal levels of CO 2 . Radiocarbon analysis revealed that high quantities of mofette soil carbon originated from the assimilation of geogenic CO 2 (up to 67%) via plant primary production and subsurface CO 2 fixation. However, the preservation and accumulation of almost undegraded organic material appeared to be facilitated by the permanent exclusion of meso-to macroscopic eukaryotes and associated physical and/or ecological traits rather than an impaired biochemical potential for soil organic matter decomposition. Our study shows how CO 2 -induced changes in diversity and functions of the soil community can foster an unusual biogeochemical profile.

Integrated multi-omics of the human gut microbiome in a case study of familial type 1 diabetes

“…Furthermore, as the functional omes display higher variability and sensitivity to perturbation 9,[11][12][13] , these variations may better reflect disease-related changes in host-microbiome interactions 14,15 . For this reason, the integration of metagenomic, metatranscriptomic and metaproteomic data is expected to yield important insights into the human microbiome 18 , as it has for environmental microbial consortia 19,20 .…”

Hypoxic and acidic — Soils on mofette fields

“…Accumulation of SOM in soils on mofette fields relative to reference sites has been frequently reported (e.g., Beaubien et al, 2008;Beulig et al, 2015Beulig et al, , 2016Kerpen, 1960;Kool et al, 2007;Nowak et al, 2015;Rennert et al, 2011;Saßmannshausen, 2010). Accumulation of SOM is not only expressed by increased contents of soil organic carbon (SOC) in the topsoils, but also by the growth of hummocks, similar to those in peat lands, and the preservation of unaltered plant debris (Flechsig et al, 2008;Kerpen, 1960;Pätzold, 2009).…”

“…Also the community structure of arbuscular mycorrhizal fungi is controlled by [CO 2 ], rather than by soil pH or available P (Maček et al, 2011). Very recently, Beulig et al (2016) reported that up to 67% of OM in soil on a mofette field originated from the assimilation of geogenic CO 2 by plant-primary production and subsurface-CO 2 fixation. They suggested that preservation and accumulation of almost unaltered SOM was facilitated by the permanent exclusion of meso-and macroscopic eukaryotes rather than by impaired biochemical potential for SOM decomposition.…”

Drilling into an active mofette: pilot-hole study of the impact of CO<sub>2</sub>-rich mantle-derived fluids on the geo–bio interaction in the western Eger Rift (Czech Republic)

“…Acetate which is produced by acetogenic bacteria may then become a valuable substrate for Fe III , Mn III,IV and SO 2− 4 reducing microorganisms as well as acetoclastic methanogens . In addition, first analyses of the microbial communities in wetland soils of the Bublák mofette field in the Cheb Basin show that both bacteria and archaea are able to incorporate 13 C-labeled CO 2 (Beulig et al, 2015(Beulig et al, , 2016. Hence, an effect of the increased CO 2 concentrations on the composition of the microbial community seems very likely.…”