Impact of low intensity summer rainfall on E. coli-discharge event dynamics with reference to sample acquisition and storage
Impact of low intensity summer rainfall on E. coli-discharge event dynamics with reference to sample acquisition and storage
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夏季低强度降雨对大肠杆菌排放事件动态的影响（参考样品采集和储存）
DOI：
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发表时间：
2015
影响因子：
3
通讯作者：
R. Quilliam
中科院分区：
文献类型：
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作者：
D. Oliver;Kenneth D. H. Porter;A. Louise Heathwaite;Ting Zhang;R. Quilliam
了解不同的降雨情景对粪便指示生物（FIO）动态在可变的现场条件下的作用是很重要的，以加强证据基础上，监管机构和土地管理人员可以根据知情的决策扩散微生物污染风险。我们试图调查低强度夏季降雨对大肠杆菌排放（Q）模式的影响，以提供新的经验数据，在基流条件下观察到的FIO浓度在源头流域尺度。此外，我们评估了使用自动采样器收集和储存淡水样本的潜在影响，以便在夏季风暴采样活动期间进行后续微生物分析。E.在苏格兰中部一个相对干燥的夏季，在六个事件中捕获了Q大肠杆菌浓度。E.大肠杆菌浓度和Q是复杂的，没有可辨别的细胞出现模式，Q在所有事件中重复。有几次，E.大肠杆菌的浓度甚至在Q略有增加的情况下也会出现，但响应并不一致，并突出了试图验证大肠杆菌的时间响应的挑战。在低强度降雨过程中，大肠杆菌相对于Q的浓度。交叉比较E.使用同时的手动抓取和自动样品收集来确定水样中的大肠杆菌浓度，在两种方法之间没有观察到浓度差异。然而，在自动进样器单元内样品储存的持续时间被发现在影响微生物水质的代表性方面更成问题，未冷藏的自动进样器显示出显著不同的E浓度。大肠杆菌相对于初始样品储存12小时后。这项研究的结果提供了重要的经验贡献，在集水区微生物动力学领域不断增长的证据基础。
Understanding the role of different rainfall scenarios on faecal indicator organism (FIO) dynamics under variable field conditions is important to strengthen the evidence base on which regulators and land managers can base informed decisions regarding diffuse microbial pollution risks. We sought to investigate the impact of low intensity summer rainfall on Escherichia coli-discharge (Q) patterns at the headwater catchment scale in order to provide new empirical data on FIO concentrations observed during baseflow conditions. In addition, we evaluated the potential impact of using automatic samplers to collect and store freshwater samples for subsequent microbial analysis during summer storm sampling campaigns. The temporal variation of E. coli concentrations with Q was captured during six events throughout a relatively dry summer in central Scotland. The relationship between E. coli concentration and Q was complex with no discernible patterns of cell emergence with Q that were repeated across all events. On several occasions, an order of magnitude increase in E. coli concentrations occurred even with slight increases in Q, but responses were not consistent and highlighted the challenges of attempting to characterise temporal responses of E. coli concentrations relative to Q during low intensity rainfall. Cross-comparison of E. coli concentrations determined in water samples using simultaneous manual grab and automated sample collection was undertaken with no difference in concentrations observed between methods. However, the duration of sample storage within the autosampler unit was found to be more problematic in terms of impacting on the representativeness of microbial water quality, with unrefrigerated autosamplers exhibiting significantly different concentrations of E. coli relative to initial samples after 12-h storage. The findings from this study provide important empirical contributions to the growing evidence base in the field of catchment microbial dynamics.