Mandelbaum R T, Shati M R, Ronen D
Department of Soils and Water, Volcani Research Institute, Beit-Dagan, Israel.
FEMS Microbiol Rev. 1997 Jul;20(3-4):489-502. doi: 10.1111/j.1574-6976.1997.tb00332.x.
The extent to which aquifer microbiota can be studied under laboratory or simulated conditions is limited by our inability to authentically duplicate natural conditions in the laboratory. Therefore, extrapolation of laboratory results to real aquifer situations is often criticized, unless validation of the data is performed in situ. Reliable data acquisition is critical for the estimation of chemical and biological reaction rates of biodegradation processes in groundwater and as input data for mathematical models. Typically, in situ geobiochemical studies relied on the injection of groundwater spiked with compounds or bacteria of interest into the aquifer, followed by monitoring the changes over time and space. In situ microcosms provide a more confined study site for measurements of microbial reactions, yet closer to natural conditions than laboratory microcosms. Two basic types of in situ aquifer microcosm have been described in recent years, and both originated from in situ instruments initially designed for geochemical measurements. Gillham et al. [Ground Water 28 (1990) 858-862] constructed an instrument that isolates a portion of an aquifer for in situ biochemical rate measurements. More recently Shati et al. [Environ. Sci. Technol. 30 (1996) 2646-2653] modified a multilayer sampler for studying the activity of inoculated bacteria in a contaminated aquifer Keeping in mind recent advances in environmental microbiology methodologies such as immunofluorescence direct counts, oligonucleotide and PCR probes, fatty acid methyl esther analysis for the detection and characterization of bacterial communities, measurement of mRNA and expression of proteins, it is evident that much new information can now be gained from in situ work. Using in situ microcosms to study bioremediation efficiencies, the fate of introduced microorganisms and general geobiochemical aquifer processes can shed more realistic light on the microbial underworld. The aim of this paper is to emphasize the importance of in situ studies and to describe two different concepts of construction and application of in situ microcosms for studying microbial activity in aquifers. The overall goal is to promote the development and utilization of these valuable and largely unexplored tools.
在实验室或模拟条件下对含水层微生物群进行研究的程度受到限制，因为我们无法在实验室中真实地复制自然条件。因此，除非在现场对数据进行验证，否则将实验室结果外推到实际含水层情况往往受到批评。可靠的数据采集对于估算地下水中生物降解过程的化学和生物反应速率以及作为数学模型的输入数据至关重要。通常，现场地球生物化学研究依赖于将添加了感兴趣的化合物或细菌的地下水注入含水层，然后监测随时间和空间的变化。现场微观世界为微生物反应的测量提供了一个更封闭的研究场所，但比实验室微观世界更接近自然条件。近年来描述了两种基本类型的现场含水层微观世界，它们都源自最初设计用于地球化学测量的现场仪器。吉尔汉姆等人[《地下水》28(1990)858 - 862]构建了一种仪器，用于隔离含水层的一部分以进行现场生化速率测量。最近，沙蒂等人[《环境科学与技术》30(1996)2646 - 2653]对多层采样器进行了改进，用于研究受污染含水层中接种细菌的活性。考虑到环境微生物学方法的最新进展，如免疫荧光直接计数、寡核苷酸和PCR探针、用于检测和表征细菌群落的脂肪酸甲酯分析、mRNA的测量和蛋白质的表达，很明显现在可以从现场工作中获得很多新信息。利用现场微观世界研究生物修复效率、引入微生物的命运以及一般的地球生物化学含水层过程，可以更真实地揭示微生物的地下世界。本文的目的是强调现场研究的重要性，并描述用于研究含水层中微生物活性的现场微观世界的两种不同构建和应用概念。总体目标是促进这些有价值且在很大程度上未被探索的工具的开发和利用。
