Pressure effects on sulfur‐oxidizing activity of Thiobacillus thioparus

Abstract

Carbon capture and storage technologies are crucial for reducing carbon emission from power plants as a response to global climate change. The CarbFix project (Iceland) aims at examining the geochemical response of injected CO2 into subsurface reservoirs. The potential role of the subsurface biosphere has been little investigated up to now. Here, we used Thiobacillus thioparus that became abundant at the CarbFix1 pilot site after injection of CO2 and purified geothermal gases in basaltic aquifer at 400–800 m depth (4–8 MPa). The capacity of T. thioparus to produce sulfate, through oxidation of thiosulfate, was measured by Raman spectroscopy as a function of pressure up to 10 MPa. The results show that the growth and metabolic activity of T. thioparus are influenced by the initial concentration of the electron donor thiosulfate. It grows best at low initial concentration of thiosulfate (here 5 g.l−1 or 31.6 mM) and best oxidizes thiosulfate into sulfate at 0.1 MPa with a yield of 14.7 ± 0.5%. Sulfur oxidation stops at 4.3 ± 0.1 MPa (43 bar). This autotrophic specie can thereby react to CO2 and H2S injection down to 430 m depth and may contribute to induced biogeochemical cycles during subsurface energy operations.

In situ Raman quantitative monitoring of methanogenesis: Culture experiments of a deep-sea cold seep methanogenic archaeon

“…Laser Raman spectroscopy is an excellent method for studying gases ( Wang et al, 2011 ; Hanf et al, 2014 ), fluids ( Facq et al, 2014 ; Li et al, 2018 ), and mineral components ( Ma et al, 2021 ). In recent years, Raman spectroscopy has been gradually applied in the studies of microbiology because of its unique advantages of being inexpensive, nondestructive, requiring a short time, exhibiting high accuracy, and enabling in situ monitoring ( Shope et al, 1987 ; Picard et al, 2007 ; Wu et al, 2015 ; Schalk et al, 2017 ; Jehlicka et al, 2019 ; Shi et al, 2020 ; Osman et al, 2021 ; Wang et al, 2022 ). Furthermore, owing to the ability of Raman spectroscopy to detect rapidly the characteristic peaks of several gas–and liquid-phase substances from a closed system, it can be used for the long-term monitoring of gas production.…”

Characterizing the Piezosphere: The Effects of Decompression on Microbial Growth Dynamics

“…Inoculating such devices for high-pressure enrichment experiments also usually requires ambient pressure conditions. Other alternatives to study microorganisms under in situ pressure conditions include (i) the implementation of optic windows in the high-pressure vessels to monitor growth and motility ( Maldonado et al, 2016 ; Garel et al, 2019 ); (ii) using high-pressure capillaries or other high-pressure cells coupled with microscopy to study molecular behaviors under extreme conditions with specific high-pressure cell using fluorescence microscopy ( Raber et al, 2006 ; Usui et al, 2012 ; Patra et al, 2017 ; Bourges et al, 2020 ); and (iii) application of spectroscopy techniques to characterize microbial metabolism under high-pressure conditions ( Kato and Fujisawa, 1998 ; Picard et al, 2007 , 2015 ; Peters et al, 2014 ; Martinez et al, 2016 ; Osman et al, 2021 ). These alternatives are promising but require both specific and costly equipment and expertise to perform high-pressure in situ monitoring, and are not-yet widespread.…”