Distribution patterns of attached and suspended bacteria in pristine and contaminated shallow aquifers studied with an in situ sediment exposure microcosm
Distribution patterns of attached and suspended bacteria in pristine and contaminated shallow aquifers studied with an in situ sediment exposure microcosm
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DOI：
10.3354/ame028117
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发表时间：
2002-06-26
影响因子：
1.4
通讯作者：
Geiger-Kaiser, M
中科院分区：
文献类型：
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作者：
Griebler, C;Mindl, B;Geiger-Kaiser, M
我们使用专门设计的充满天然基质的微环境来研究微生物在浅层含水层中的定植。灭菌后的沉积物暴露于3种不同物理、化学和生物特性的地下水中：(1)原始地下水（PI 92）；(2)原址观测井地下水（omv11）；(3)垃圾填埋场污染地下水（omv5）。垃圾填埋场的悬浮细菌数量最高(4.0 +/- 4,2[标准差，SD] × 10(6)个细胞cm(-3))，是井水(2.5 +/- 3.0 × 10（5)个细胞cm(-3)）的16倍，是原始地下水(4.1 +/- 1.3 × 10（4)个细胞cm(-3)）的96倍。微生物群落中的沉积物迅速定植，暴露10个月后附着细菌总数在垃圾填埋场最高(1.8 +/- 0.4 × 10(8)个细胞cm(-3))，其次是井水沉积物(1.5 +/- 0.5 × 10（8)个细胞cm(-3)）和原始地下水(5.0 +/- 1.5 × 10（7)个细胞cm(-3)）。从图像分析中估计，垃圾填埋场附着的细胞平均碳含量（28 +/- 36 fgC细胞（-1））高于井水（24 +/- 23 fgC细胞（-1））和原始地下水（21 +/- 23 fgC细胞（-1））。接触10个月后，微生物与悬浮菌的附着比在原始地下水中最高（1657:1），在污染地点最低（59:1）。根据我们的研究结果，我们强调了多孔地下系统中附着微生物群落的重要性，并强调了地下水和沉积物样品对地下微生物特征的重要意义。此外，浅层含水层系统中附着与悬浮细菌的比例被认为是主要营养浓度的一个指标。
We used specially designed microcosms filled with natural substrate to study microbial colonization in a shallow aquifer. Sterilized sediments were exposed to 3 types of groundwater varying in physical, chemical and biological characteristics: (1) pristine groundwater (site PI 92); (2) groundwater in an observation well at a pristine site (OMV 11); and (3) contaminated groundwater at a landfill site (OMV 5). The number of suspended bacteria was always highest at the landfill site (4.0 +/- 4,2 [standard deviation, SD] x 10(6) cells cm(-3)), i.e. on average 16 times higher than in the well water (2.5 +/- 3.0 x 10(5) cells cm(-3)) and 96 times higher than in the pristine groundwater (4.1 +/- 1.3 x 10(4) cells cm(-3)). Sediments in the microcosms were rapidly colonized and the total number of attached bacteria after 10 mo of exposure was highest at the landfill site (1.8 +/- 0.4 x 10(8) cells cm(-3)) followed by the sediment incubated in well water (1.5 +/- 0.5 x 10(8) cells cm(-3)) and in pristine groundwater (5.0 +/- 1.5 x 10(7) cells cm(-3)). As estimated from image analysis, attached cells from the landfill site were on average characterized by higher cell carbon contents (28 +/- 36 fgC cell(-1)) than at the well water (24 +/- 23 fgC cell(-1)) and the pristine groundwater site (21 +/- 23 fgC cell(-1)). The ratio of attached to suspended bacteria after 10 mo of exposure was highest in the microcosm incubated in pristine groundwater (1657:1) and lowest at the contaminated site (59:1). On the basis of our results we emphasize the importance of attached microbial communities in porous subsurface systems and underline the need for groundwater as well as sediment samples for a serious microbiological characterization of the subsurface. Furthermore, the ratio of attached to suspended bacteria in shallow aquifer systems is suggested to be an indicator of prevailing nutrient concentrations.