Institute of Groundwater Ecology, Helmholtz Zentrum München, German Research Center for Environmental Health, GmbH, Neuherberg, Germany.
FEMS Microbiol Ecol. 2012 Jul;81(1):230-42. doi: 10.1111/j.1574-6941.2012.01371.x. Epub 2012 Apr 23.
Seasonal patterns of groundwater and sediment microbial communities were explored in a hydrologically dynamic alpine oligotrophic porous aquifer, characterized by pronounced groundwater table fluctuations. Rising of the groundwater level in consequence of snow melting water recharge was accompanied by a dramatic drop of bacterial Shannon diversity in groundwater from H' = 3.22 ± 0.28 in autumn and winter to H' = 1.31 ± 0.35 in spring and summer, evaluated based on T-RFLP community fingerprinting. Elevated numbers of bacteria in groundwater in autumn followed nutrient inputs via recharge from summer rains and correlated well with highest concentrations of assimilable organic carbon. Sterile sediments incubated to groundwater in monitoring wells were readily colonized reaching maximum cell densities within 2 months, followed by a consecutive but delayed increase and leveling-off of bacterial diversity. After 1 year of incubation, the initially sterile sediments exhibited a similar number of bacteria and Shannon diversity when compared to vital sediment from a nearby river incubated in parallel. The river bed sediment microbial communities hardly changed in composition, diversity, and cell numbers during 1 year of exposure to groundwater. Summing up, the seasonal hydrological dynamics were found to induce considerable dynamics of microbial communities suspended in groundwater, while sediment communities seem unaffected and stable in terms of biomass and diversity.
探讨了水文动态高寒贫营养多孔含水层中地下水和沉积物微生物群落的季节性变化模式，该含水层以明显的地下水位波动为特征。由于融雪补给导致地下水位上升，地下水中的细菌 Shannon 多样性急剧下降，从秋季和冬季的 H' = 3.22 ± 0.28 下降到春季和夏季的 H' = 1.31 ± 0.35，这是基于 T-RFLP 群落指纹图谱评估的。秋季地下水中的细菌数量增加，这是由于夏季雨水补给带来的养分输入所致，与可同化有机碳的最高浓度密切相关。在监测井中用地下水培养无菌沉积物，很容易被细菌定殖，在 2 个月内达到最大细胞密度，随后细菌多样性连续但延迟增加并达到稳定。经过 1 年的培养，与附近河流中同时培养的有活力的沉积物相比，最初无菌的沉积物表现出相似数量的细菌和 Shannon 多样性。河床沉积物微生物群落的组成、多样性和细胞数量在 1 年的地下水暴露过程中几乎没有变化。总的来说，季节性水文动态被发现会引起地下水中悬浮微生物群落的相当大的动态变化，而沉积物群落在生物量和多样性方面似乎不受影响且稳定。
