High-elevation arid regions harbor microbial communities reliant on metabolic niches and flexibility to survive under biologically stressful conditions, including nutrient limitation that necessitates the utilization of atmospheric trace gases as electron donors. Geothermal springs present “oases” of microbial activity, diversity, and abundance by delivering water and substrates, including reduced gases. However, it is unknown whether these springs exhibit a gradient of effects, increasing the spatial reach of their impact on trace gas-oxidizing microbes in the surrounding soils. This study assessed whether proximity to Polloquere, a high-altitude geothermal spring in an Andean salt flat, alters the diversity and metabolic structure of nearby soil bacterial populations compared to the surrounding cold desert. Recovered DNA quantities and metagenomic analyses indicate that the spring represents an oasis for microbes in this challenging environment, supporting greater biomass with more diverse metabolic functions in proximal soils that declines sharply with radial distance from the spring. Despite the sharp decrease in biomass, potential rates of atmospheric hydrogen (H2) and carbon monoxide (CO) uptake increase away from the spring. Kinetic estimates suggest that this activity is due to high-affinity trace gas consumption, likely as a survival strategy for energy and/or carbon acquisition. These results demonstrate that Polloquere regulates a gradient of diverse microbial communities and metabolisms, culminating in increased activity of trace gas-oxidizers as the influence of the spring yields to that of the regional salt flat environment. This suggests that the spring holds local importance within the context of the broader salt flat and potentially represents a model ecosystem for other geothermal systems in high-altitude desert environments.

中文翻译：

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在高海拔安第斯寒冷沙漠中，微量气体氧化土壤细菌的流行随着距 Polloquere 温泉的径向距离的增加而增加

高海拔干旱地区的微生物群落依靠代谢生态位和灵活性在生物应激条件下生存，包括营养限制，需要利用大气微量气体作为电子供体。地热泉通过输送水和基质（包括减少的气体）呈现出微生物活动、多样性和丰富性的“绿洲”。然而，尚不清楚这些泉水是否表现出梯度效应，从而增加了它们对周围土壤中微量气体氧化微生物影响的空间范围。这项研究评估了与周围寒冷的沙漠相比，靠近安第斯盐滩高海拔地热温泉 Polloquere 是否会改变附近土壤细菌种群的多样性和代谢结构。回收的 DNA 数量和宏基因组分析表明，泉水在这一充满挑战的环境中代表了微生物的绿洲，支持近端土壤中具有更多样化代谢功能的更大生物量，而随着距泉水的径向距离的增加，生物量急剧下降。尽管生物量急剧下降，但远离春季，大气中氢气 (H2) 和一氧化碳 (CO) 吸收的潜在速率却有所增加。动力学估计表明，这种活动是由于高亲和力微量气体消耗所致，可能是作为能源和/或碳获取的生存策略。这些结果表明，Polloquere 调节不同微生物群落和新陈代谢的梯度，最终导致微量气体氧化剂的活性增加，因为泉水产量对区域盐滩环境的影响。这表明该泉水在更广泛的盐滩背景下具有当地的重要性，并可能代表高海拔沙漠环境中其他地热系统的模型生态系统。