| Title | Microbiomes in soils exposed to naturally high concentrations of CO2 (Bossoleto Mofette Tuscany, Italy) |
| Abstract | Direct and indirect effects of extremely high geogenic CO2 levels, commonly occurring in volcanic and hydrothermal environments, on biogeochemical processes in soil are poorly understood. This study investigated a sinkhole in Italy where long-term emissions of thermometamorphic-derived CO2 are associated with accumulation of carbon in the topsoil and removal of inorganic carbon in low pH environments at the bottom of the sinkhole. The comparison between interstitial soil gasses and those collected in an adjacent bubbling pool and the analysis of the carbon isotopic composition of CO2 and CH4 clearly indicated the occurrence of CH4 oxidation and negligible methanogenesis in soils at the bottom of the sinkhole. Extremely high CO2 concentrations resulted in higher microbial abundance (up to 4 109 cell g-1 DW) and a lower microbial diversity by favoring bacteria already reported to be involved in acetogenesis in mofette soils (i.e., Firmicutes, Chloroflexi, and Acidobacteria). Laboratory incubations to test the acetogenic and methanogenic potential clearly showed that all the mofette soil supplied with hydrogen gas displayed a remarkable CO2 fixation potential, primarily due to the activity of acetogenic microorganisms. By contrast, negligible production of acetate occurred in control tests incubated with the same soils, under identical conditions, without the addition of hydrogen. In this study, we report how changes in diversity and functions of the soil microbial community - induced by high CO2 concentration - create peculiar biogeochemical profile. CO2 emission affects carbon cycling through: (i) inhibition of the decomposition of the organic carbon and (ii) promotion of CO2-fixation via the acetyl-CoA pathway. Sites naturally exposed to extremely high CO2 levels could potentially represent an untapped source of microorganisms with unique capabilities to catalytically convert CO2 into valuable organic chemicals and fuels. |
| Source | Frontiers in microbiology 10, pp. Article number 2238 |
| Keywords | mofetteCO2bacteriasoilacetogenesis |
| Journal | Frontiers in microbiology |
| Editor | Frontiers Research Foundation,, Lausanne, Svizzera |
| Year | 2019 |
| Type | Articolo in rivista |
| DOI | 10.3389/fmicb.2019.02238 |
| Authors | Fazi S., Ungaro F., Venturi S., Vimercati L., Cruz Viggi C., Baronti S., Ugolini F., Calzolari C., Tassi F., Vaselli O., Raschi A., Aulenta F. |
| Text | 407381 2019 10.3389/fmicb.2019.02238 ISI Web of Science WOS 000491331900001 Scopus 2 s2.0 85073685666 mofette CO2 bacteria soil acetogenesis Microbiomes in soils exposed to naturally high concentrations of CO2 Bossoleto Mofette Tuscany, Italy Fazi S., Ungaro F., Venturi S., Vimercati L., Cruz Viggi C., Baronti S., Ugolini F., Calzolari C., Tassi F., Vaselli O., Raschi A., Aulenta F. Water Research Institute, National Research Council IRSA CNR , Rome, Italy; Institute of BioEconomy National Research Council IBE CNR , Florence, Italy; Institute of Geosciences and Earth Resources, National Research Council IGG CNR , Florence, Italy; Department of Earth Sciences, University of Florence, Florence, Italy; Department of Ecology and Evolutionary Biology, University of Colorado Boulder, Boulder, CO, United States Direct and indirect effects of extremely high geogenic CO2 levels, commonly occurring in volcanic and hydrothermal environments, on biogeochemical processes in soil are poorly understood. This study investigated a sinkhole in Italy where long term emissions of thermometamorphic derived CO2 are associated with accumulation of carbon in the topsoil and removal of inorganic carbon in low pH environments at the bottom of the sinkhole. The comparison between interstitial soil gasses and those collected in an adjacent bubbling pool and the analysis of the carbon isotopic composition of CO2 and CH4 clearly indicated the occurrence of CH4 oxidation and negligible methanogenesis in soils at the bottom of the sinkhole. Extremely high CO2 concentrations resulted in higher microbial abundance up to 4 109 cell g 1 DW and a lower microbial diversity by favoring bacteria already reported to be involved in acetogenesis in mofette soils i.e., Firmicutes, Chloroflexi, and Acidobacteria . Laboratory incubations to test the acetogenic and methanogenic potential clearly showed that all the mofette soil supplied with hydrogen gas displayed a remarkable CO2 fixation potential, primarily due to the activity of acetogenic microorganisms. By contrast, negligible production of acetate occurred in control tests incubated with the same soils, under identical conditions, without the addition of hydrogen. In this study, we report how changes in diversity and functions of the soil microbial community induced by high CO2 concentration create peculiar biogeochemical profile. CO2 emission affects carbon cycling through i inhibition of the decomposition of the organic carbon and ii promotion of CO2 fixation via the acetyl CoA pathway. Sites naturally exposed to extremely high CO2 levels could potentially represent an untapped source of microorganisms with unique capabilities to catalytically convert CO2 into valuable organic chemicals and fuels. 10 Published version https //www.frontiersin.org/journals/microbiology# 12/09/2019 Microbiomes in soils exposed to naturally high concentrations of CO2 Bossoleto Mofette Tuscany, Italy FAZI.pdf Articolo in rivista Frontiers Research Foundation, 1664 302X Frontiers in microbiology Frontiers in microbiology Front. microbiol. Frontiers in microbiology orlandovaselli VASELLI ORLANDO francotassi TASSI FRANCO VENTURI STEFANIA fabrizio.ungaro UNGARO FABRIZIO stefano.fazi FAZI STEFANO federico.aulenta AULENTA FEDERICO carolina.cruzviggi CRUZ VIGGI CAROLINA silvia.baronti BARONTI SILVIA francesca.ugolini UGOLINI FRANCESCA antonio.raschi RASCHI ANTONIO mariacostanza.calzolari CALZOLARI MARIA COSTANZA TA.P05.014.002 Studio della distribuzione degli elementi e degli isotopi nell astenosfera, litosfera, idrosfera e atmosfera |
