Geomicrobiology/Microbial Ecology Environmental Analytical Microscopy, Center for Applied Geosciences, University of Tübingen, Tübingen, Germany.
Environ Microbiol. 2012 Nov;14(11):2851-69. doi: 10.1111/j.1462-2920.2012.02724.x. Epub 2012 Mar 12.
Environmental microbiology research increasingly focuses on the single microbial cell as the defining entity that drives environmental processes. The interactions of individual microbial cells with each other, the environment and with higher organisms shape microbial communities and control the functioning of whole ecosystems. A single-cell view of microorganisms in their natural environment requires analytical tools that measure both cell function and chemical speciation at the submicrometre scale. Here we review the technical capabilities and limitations of high-resolution secondary ion mass spectrometry (NanoSIMS) and scanning transmission (soft) X-ray microscopy (STXM) and give examples of their applications. Whereas NanoSIMS can be combined with isotope-labelling, thereby localizing the distribution of cellular activities (e.g. carbon/nitrogen fixation/turnover), STXM provides information on the location and chemical speciation of metabolites and products of redox reactions. We propose the combined use of both techniques and discuss the technical challenges of their joint application. Both techniques have the potential to enhance our understanding of cellular mechanisms and activities that contribute to microbially mediated processes, such as the biogeochemical cycling of elements, the transformation of contaminants and the precipitation of mineral phases.
环境微生物学研究越来越关注单个微生物细胞，将其作为驱动环境过程的决定性实体。单个微生物细胞彼此之间、与环境以及与高等生物的相互作用塑造了微生物群落，并控制着整个生态系统的功能。在自然环境中观察微生物的单细胞视角需要分析工具，这些工具可以在亚微米尺度上测量细胞功能和化学形态。在这里，我们回顾了高分辨率二次离子质谱（NanoSIMS）和扫描透射（软）X 射线显微镜（STXM）的技术能力和局限性，并给出了它们应用的实例。虽然 NanoSIMS 可以与同位素标记相结合，从而定位细胞活动（如碳/氮固定/周转）的分布，但 STXM 提供了关于代谢物和氧化还原反应产物的位置和化学形态的信息。我们建议联合使用这两种技术，并讨论它们联合应用的技术挑战。这两种技术都有可能增强我们对细胞机制和活动的理解，这些机制和活动有助于微生物介导的过程，如元素的生物地球化学循环、污染物的转化和矿物相的沉淀。
