Examinando por Autor "Carrizo, D."

Mostrando 1 - 2 de 2

Acceso Abierto
Biological production of H2, CH4 and CO2 in the deep subsurface of the Iberian Pyrite Belt
(Society for Applied Microbiology, 2021-05-10) Sanz, J. L.; Escudero, C.; Carrizo, D.; Amils, R.; Rodríguez Rivas, Noé; Agencia Estatal de Investigación (AEI); Sanz, J. L. [0000-0003-3226-3967]; Rodríguez, N. [0000-0003-4109-4851]; Escudero, C. [0000-0003-1240-4144]; Carrizo, D. [0000-0003-1568-4591]; Amils, R. [0000-0002-7560-1033]
Most of the terrestrial deep subsurfaces are oligotrophic environments in which some gases, mainly H2, CH4 and CO2, play an important role as energy and/or carbon sources. In this work, we assessed their biotic and abiotic origin in samples from subsurface hard-rock cores of the Iberian Pyrite Belt (IPB) at three different depths (414, 497 and 520 m). One set of samples was sterilized (abiotic control) and all samples were incubated under anaerobic conditions. Our results showed that H2, CH4 and CO2 remained low and constant in the sterilized controls while their levels were 4, 4.1 and 2.5 times higher respectively, in the unsterilized samples compared to the abiotic controls. The δ13CCH4-values measured in the samples (range −31.2 to −43.0 ‰) reveals carbon isotopic signatures that are within the range for biological methane production. Possible microorganisms responsible for the biotic production of the gases were assessed by CARD-FISH. The analysis of sequenced genomes of detected microorganisms within the subsurface of the IPB allowed to identify possible metabolic activities involved in H2 (Rhodoplanes, Shewanella and Desulfosporosinus), CH4 (Methanobacteriales) and CO2 production. The obtained results suggest that part of the H2, CH4 and CO2 detected in the deep subsurface has a biological origin.
Acceso Abierto
Methanogenesis at High Temperature, High Ionic Strength and Low pH in the Volcanic Area of Dallol, Ethiopia
(Multidisciplinary Digital Publishing Institute (MDPI), 2021-06-06) Sanz, J. L.; Escudero, C.; Carrizo, D.; Amils, R.; Gómez, F.; Rodríguez Rivas, Noé; Agencia Estatal de Investigación (AEI); Sanz, J. L. [0000-0003-3226-3967]; Escudero, C. [0000-0003-1240-4144]; Carrizo, D. [0000-0003-1568-4591]; Amils, R. [0000-0002-7560-1033]; Gómez, F. [0000-0001-9977-7060]; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
The Dallol geothermal area originated as a result of seismic activity and the presence of a shallow underground volcano, both due to the divergence of two tectonic plates. In its ascent, hot water dissolves and drags away the subsurface salts. The temperature of the water that comes out of the chimneys is higher than 100 °C, with a pH close to zero and high mineral concentration. These factors make Dallol a polyextreme environment. So far, nanohaloarchaeas, present in the salts that form the walls of the chimneys, have been the only living beings reported in this extreme environment. Through the use of complementary techniques: culture in microcosms, methane stable isotope signature and hybridization with specific probes, the methanogenic activity in the Dallol area has been assessed. Methane production in microcosms, positive hybridization with the Methanosarcinales probe and the δ13CCH4-values measured, show the existence of extensive methanogenic activity in the hydrogeothermic Dallol system. A methylotrophic pathway, carried out by Methanohalobium and Methanosarcina-like genera, could be the dominant pathway for methane production in this environment.