Ugolini Fabio, Henneberger Ruth, Bürgmann Helmut, Zeyer Josef, Schroth Martin H
Institute for Biogeochemistry and Pollutant Dynamics, ETH Zürich, Universitätstrasse 16, CH-8092 Zürich, Switzerland.
Ground Water. 2014 Sep-Oct;52(5):737-47. doi: 10.1111/gwat.12105. Epub 2013 Aug 12.
Sampling methods for characterization of microbial communities in aquifers should target both suspended and attached microorganisms (biofilms). We investigated the effectiveness and reproducibility of low-frequency (200 Hz) sonication pulses on improving extraction efficiency and quality of microorganisms from a petroleum-contaminated aquifer in Studen (Switzerland). Sonication pulses at different power levels (0.65, 0.9, and 1.1 kW) were applied to three different groundwater monitoring wells. Groundwater samples extracted after each pulse were compared with background groundwater samples for cell and adenosine tri-phosphate concentration. Turbidity values were obtained to assess the release of sediment fines and associated microorganisms. The bacterial community in extracted groundwater samples was analyzed by terminal-restriction-fragment-length polymorphism and compared with communities obtained from background groundwater samples and from sediment cores. Sonication enhanced the extraction efficiency up to 13-fold, with most of the biomass being associated with the sediment fines extracted with groundwater. Consecutive pulses at constant power were decreasingly effective, while pulses with higher power yielded the best results both in terms of extraction efficiency and quality. Our results indicate that low-frequency sonication may be a viable and cost-effective tool to improve the extraction of microorganisms from aquifers, taking advantage of existing groundwater monitoring wells.
用于表征含水层中微生物群落的采样方法应针对悬浮和附着的微生物（生物膜）。我们研究了低频（200 Hz）超声脉冲对提高瑞士施图登一处受石油污染含水层中微生物提取效率和质量的有效性及可重复性。将不同功率水平（0.65、0.9和1.1千瓦）的超声脉冲应用于三口不同的地下水监测井。每次脉冲后提取的地下水样本与背景地下水样本进行细胞和三磷酸腺苷浓度比较。通过测量浊度值来评估沉积物细颗粒及相关微生物的释放情况。利用末端限制性片段长度多态性分析提取的地下水样本中的细菌群落，并与背景地下水样本和沉积物岩芯中的群落进行比较。超声处理使提取效率提高了13倍，大部分生物量与随地下水提取出的沉积物细颗粒相关。在恒定功率下连续脉冲的效果逐渐降低，而较高功率的脉冲在提取效率和质量方面均产生了最佳结果。我们的结果表明，利用现有的地下水监测井，低频超声处理可能是一种可行且经济高效的工具，可用于提高从含水层中提取微生物的效率。
