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.

中文翻译：

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压力对硫代硫杆菌硫氧化活性的影响

碳捕获和储存技术对于减少发电厂的碳排放以应对全球气候变化至关重要。CarbFix 项目（冰岛）旨在检查注入地下储层的 CO _{2的地球化学反应。}到目前为止，地下生物圈的潜在作用很少被研究。在这里，我们使用了在 400-800 m 深度（4-8 MPa）的玄武岩含水层中注入 CO _{2和纯化地热气体后在}CarbFix1 试验场变得丰富的硫代硫杆菌。T. thioparus的能力通过硫代硫酸盐的氧化产生硫酸盐，通过拉曼光谱测量，作为高达 10 MPa 的压力的函数。结果表明，T. thioparus的生长和代谢活性受电子供体硫代硫酸盐初始浓度的影响。它在低硫代硫酸盐初始浓度（此处为 5 gl ^-1或 31.6 mM）下生长最好，并且在 0.1 MPa 时最好将硫代硫酸盐氧化成硫酸盐，产率为 14.7 ± 0.5%。硫氧化在 4.3 ± 0.1 MPa (43 bar) 时停止。因此，这种自养物种可以对下至 430 m 深度的 CO ₂和 H ₂ S 注入作出反应，并可能有助于在地下能源操作期间诱导生物地球化学循环。