Our understanding of Earth's rock-hosted subsurface biosphere has advanced over the past two decades through the collection and analysis of fluids and rocks from aquifers within the continental and oceanic crust. Improvements in cell extraction, cell sorting, DNA sequencing, and techniques for detecting cell distributions and activity have revealed how the combination of lithology, permeability, and fluid mixing processes controls the diversity and heterogeneous distribution of microbial communities in fractured rock systems. However, the functions of most organisms, and the rates of their activity and growth, remain largely unknown. To mechanistically understand what physiochemical and hydrological factors control the rock-hosted biosphere, future studies are needed to characterize the physiology of microorganisms adapted to mineral-associated growth under energy- and nutrient-limited conditions. Experiments should be designed to detect synergistic interactions between microorganisms, and between microorganisms and minerals, at highly variable turnover rates.▪The heterogeneous distribution of the rock-hosted biosphere is controlled by variations in porosity, permeability, and chemical disequilibrium.▪Several imaging and chemical techniques can sensitively detect microbial activity within the rock-hosted biosphere.▪The physiology and turnover rates of the subsurface rock-hosted biosphere remain poorly known.

中文翻译：

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岩石承载的生物圈


在过去的二十年里，通过收集和分析大陆和海洋地壳含水层中的流体和岩石，我们对地球岩石赋存的地下生物圈有了更深入的了解。细胞提取、细胞分选、DNA 测序以及检测细胞分布和活性的技术的改进揭示了岩性、渗透性和流体混合过程的结合如何控制裂隙岩石系统中微生物群落的多样性和异质分布。然而，大多数生物体的功能及其活动和生长速度在很大程度上仍然是未知的。为了从机制上了解哪些理化和水文因素控制着岩石承载的生物圈，需要未来的研究来表征在能量和营养有限条件下适应矿物相关生长的微生物的生理学。应设计实验以检测微生物之间以及微生物与矿物之间在高度可变的周转率下的协同相互作用。▪岩石承载的生物圈的异质分布受孔隙度、渗透性和化学不平衡的变化控制。▪几种成像和化学技术可以灵敏地检测岩石承载的生物圈内的微生物活动。▪地下岩石承载的生物圈的生理学和周转率仍然鲜为人知。