Microbial life under extreme CO2 exhalations

在莫夫石中，地源二氧化碳以极高的浓度排放到大气中，导致土壤酸化和缺氧条件。定居在莫夫特核心区的微生物群落必须能够容忍这些极端情况，并可能与未受影响的陆地参照点截然不同。由于在地质水库中捕获二氧化碳被认为是一种很有前途的处置策略，莫夫岩可能是研究二氧化碳储存和泄漏对生物地球化学过程和微生物群落的潜在生态影响的理想地点。因此，该项目将揭开栖息在普莱斯纳山谷(西北部-捷克)的沼泽中微生物群落的多样性和生物地球化学。在没有氧气的情况下，二氧化碳的同化及其作为终端电子受体的使用对莫夫类的微生物过程应该是重要的。孔隙水和土壤气体化合物中13C的组成与特定古生物和细菌脂类的13C消耗有关，这将进一步深入了解适应开发地源二氧化碳的微生物种群的优势。由于甲烷在大多数地点不会释放，产乙酸菌可能会将二氧化碳还原为乙酸酯，这将根据其功能FHS标记基因进行量化。它们的代谢多样性和耐氧性可能使乙酸菌既可以在二氧化碳浓度极高的缺氧土壤中定居，也可以在植物的根际定居，如绒毛扇贝，它似乎通过将O2输送到根来适应富含二氧化碳的土壤。对于新的“嗜莫夫”微生物的浓缩和潜在的分离，将使用梯度管技术并根据现场条件进行调整。

In mofettes, geogenic CO2 is emitted in extremely high concentrations to the atmosphere leading to soil acidification and anoxic conditions. The microbial community colonizing the core zone of mofettes has to be able to tolerate these extremes and might be distinct from unaffected terrestrial reference sites. Since capture of CO2 in geological reservoirs is discussed as promising disposal strategy, mofettes might be an ideal site to study potential ecological impacts of CO2 storage and leakage on biogeochemical processes and microbial communities. Thus, this project will unravel the diversity and biogeochemistry of the microbial community inhabiting a mofette located in the Plesna valley (NW-Czechia). The assimilation of CO2 and its use as terminal electron acceptor in the absence of oxygen should be significant for microbial processes in mofettes. The composition of 13C in pore water and soil gas compounds linked with 13C depletion of specific archaeal and bacterial lipids will give further insights into the dominance of microbial populations adapted to exploiting geogenic CO2. Since CH4 is not emitted at most mofette sites, CO2 might be reduced to acetate by acetogenic bacteria which will be quantified based on their functional fhs marker gene. Their metabolic versatility and oxygen tolerance might enable acetogens to colonize both anoxic soils with extremely high CO2 concentrations and also the rhizosphere of plants, like Eriophorum vaginatum, that appears to be adapted to CO2-rich soils by the transport of O2 to their roots. For enrichment and potential isolation of novel “moffetophilic” microorganisms, the gradient tube technique will be used and adjusted to the in situ conditions.