Department of Vaccinology and Applied Microbiology, Helmholtz Centre for Infection Research (HZI), Inhoffenstrasse 7, D-38124 Braunschweig, Germany.
Water Res. 2013 Oct 1;47(15):5614-30. doi: 10.1016/j.watres.2013.06.034. Epub 2013 Jun 29.
In temperate regions, seasonal variability of environmental factors affects the bacterial community in source water and finished drinking water. Therefore, the bacterial core community and its seasonal variability in cold and the respective hot drinking water was investigated. The bacterial core community was studied by 16S rRNA-based SSCP fingerprint analyses and band sequencing of DNA and RNA extracts of cold and hot water (60 °C). The bacterial communities of cold and hot drinking water showed a highly different structure and phylogenetic composition both for RNA and DNA extracts. For cold drinking water substantial seasonal dynamics of the bacterial community was observed related to environmental factors such as temperature and precipitation affecting source and drinking water. Phylogenetic analyses of the cold water community indicated that the majority of phylotypes were very closely affiliated with those detected in former studies of the same drinking water supply system (DWSS) in the preceding 6 years, indicating a high stability over time. The hot water community was very stable over time and seasons and highly distinct from the cold water with respect to structure and composition. The hot water community displayed a lower diversity and its phylotypes were mostly affiliated with bacteria of high temperature habitats with high growth rates indicated by their high RNA content. The conversion of the cold to the hot water bacterial community is considered as occurring within a few hours by the following two processes, i) by decay of most of the cold water bacteria due to heating, and ii) rapid growth of the high temperature adapted bacteria present in the hot water (co-heated with the cold water in the same device) using the nutrients released from the decaying cold water bacteria. The high temperature adapted bacteria originated partially from low abundant but beforehand detected members of the cold water; additionally, the rare members ("seed bank ") of the cold water are considered as a source.
在温带地区，环境因素的季节性变化会影响水源水和成品饮用水中的细菌群落。因此，研究了寒冷地区和相应热水中的细菌核心群落及其季节性变化。通过基于 16S rRNA 的 SSCP 指纹图谱分析和冷、热水（60°C）DNA 和 RNA 提取物的带测序研究了细菌核心群落。冷、热水的细菌群落结构和系统发育组成均有很大差异，无论是 DNA 还是 RNA 提取物。对于冷水，观察到细菌群落的实质性季节性动态，与影响水源和饮用水的环境因素（如温度和降水）有关。冷水群落的系统发育分析表明，大多数类群与之前在同一饮用水供应系统（DWSS）中进行的 6 年研究中检测到的类群密切相关，表明随着时间的推移具有高度的稳定性。热水群落随着时间和季节的推移非常稳定，与结构和组成上与冷水有很大的不同。热水群落的多样性较低，其类群主要与高温栖息地的细菌有关，这些细菌的高增长率由其高 RNA 含量表明。冷热水细菌群落的转换被认为是通过以下两个过程在几个小时内发生的，i）由于加热，大部分冷水细菌的衰减，和 ii）存在于热水中的高温适应细菌（与冷水在同一设备中共同加热）利用从衰减的冷水细菌释放的营养物质快速生长。高温适应细菌部分来源于先前检测到的冷水中低丰度但存在的成员，此外，冷水的稀有成员（“种子库”）被认为是一个来源。
