Peduzzi Peter, Luef Birgit
University of Vienna, Department of Freshwater Ecology, Althanstrasse 14, 1090 Vienna, Austria.
Aquat Sci. 2008 May;70(2):186-194. doi: 10.1007/s00027-008-8068-3.
A short overview of currently available studies on the ecology of viruses in running waters is provided. Additionally, a survey was conducted on the dynamics of both viruses and bacteria in an isolated floodplain segment of the Danube River and in the main channel near Vienna (Austria) during the hydrologically most dynamic phase (spring - summer). The study evaluates the differences between the main channel and the floodplain segment for suspended particle abundance and quality in relation to bacterial and viral parameters; both free-living forms and those attached to particles are examined. The hydrological disconnection of these two contrasting sampling sites influenced particle abundance and quality as well as the distribution of free-living vs. attached bacteria and viruses. The per-cell activity of bacteria attached to particles was significantly higher than that of the free-living fraction, particularly in the isolated water body. The abundance of bacteria and viruses on particles depended on particle quality (size). In the main channel, bacteria were significantly more abundant on surfaces (per mm(2)) of suspended matter > 5 μm (aggregates with organic constituents) compared to particles < 5 μm (mostly mineral grains). In the isolated water body, both bacteria and viruses were more abundant on the larger particles/aggregates. Data from both locations revealed a positive correlation between abundance of particles > 5μm and attached viruses; free-living viruses were less abundant at high > 5μm particle loads. Only in the isolated floodplain section was viral abundance positively influenced by elevated per-cell productivity of potential host bacteria. The results demonstrate that system variability on a relatively small topographical scale (within a river-floodplain system) has consequences for microbial life, including viruses.
本文提供了关于流水环境中病毒生态学现有研究的简要概述。此外，还对多瑙河一段孤立的洪泛区以及奥地利维也纳附近主河道在水文动态最活跃阶段（春夏季）的病毒和细菌动态进行了调查。该研究评估了主河道和洪泛区在悬浮颗粒丰度和质量方面与细菌和病毒参数相关的差异；同时研究了自由生活形式以及附着在颗粒上的形式。这两个截然不同的采样点的水文分隔影响了颗粒的丰度和质量，以及自由生活与附着细菌和病毒的分布。附着在颗粒上的细菌的细胞活性显著高于自由生活部分，特别是在孤立水体中。颗粒上细菌和病毒的丰度取决于颗粒质量（大小）。在主河道中，与小于5μm的颗粒（主要是矿物颗粒）相比，大于5μm的悬浮物（含有有机成分的聚集体）表面（每平方毫米）上的细菌数量显著更多。在孤立水体中，细菌和病毒在较大颗粒/聚集体上更为丰富。来自两个地点的数据都显示，大于5μm的颗粒丰度与附着病毒之间存在正相关；在大于5μm颗粒负载较高时，自由生活病毒的数量较少。只有在孤立的洪泛区部分，潜在宿主细菌的细胞生产力提高对病毒丰度有积极影响。结果表明，在相对较小的地形尺度（河流-洪泛区系统内）上的系统变异性会对包括病毒在内的微生物生命产生影响。
