Pennine Water Group, Department of Civil and Structural Engineering, Sir Frederick Mappin Building, University of Sheffield, Sheffield, S1 3JD, UK.
Theoretical Biology and Bioinformatics, Science for Life, Utrecht University, Hugo R. Kruytgebouw, Padualaan 8, 3584, CH, Utrecht, the Netherlands; Centre for Molecular and Biomolecular Informatics, Radboud University Medical Centre, Geert Grooteplein Zuid 26-28, 6525, GA, Nijmegen, the Netherlands.
Water Res. 2020 Apr 15;173:115586. doi: 10.1016/j.watres.2020.115586. Epub 2020 Feb 5.
Drinking water distribution systems host complex microbial communities as biofilms that interact continuously with delivered water. Understanding the diversity, behavioural and functional characteristics will be a requisite for developing future monitoring strategies and protection against water-borne health risks. To improve understanding, this study investigates mobilisation and accumulation behaviour, microbial community structure and functional variations of biofilms developing on different pipe materials from within an operational network. Samples were collected from four pipes during a repeated flushing operation three months after an initial visit that used hydraulic forces to mobilise regenerating biofilms yet without impacting the upstream network. To minimise confounding factors, test sections were chosen with comparable daily hydraulic regimes, physical dimensions, and all connected straight of a common trunk main and within close proximity, hence similar water chemistry, pressure and age. Taxonomical results showed differences in colonising communities between pipe materials, with several genera, including the bacteria Pseudomonas and the fungi Cladosporium, present in every sample. Diverse bacterial communities dominated compared to more homogeneous fungal, or mycobiome, community distribution. The analysis of bacterial/fungal networks based on relative abundance of operational taxonomic units (OTUs) indicated microbial communities from cast iron pipes were more stable than communities from the non-ferrous pipe materials. Novel analysis of functional traits between all samples were found to be mainly associated to mobile genetic elements that play roles in determining links between cells, including phages, prophages, transposable elements, and plasmids. The use of functional traits can be considered for development in future surveillance methods, capable of delivering network condition information beyond that of limited conventional faecal indicator tests, that will help protect water quality and public health.
饮用水分配系统是复杂微生物群落的栖息地，这些群落以生物膜的形式存在，并与输送的水不断相互作用。了解其多样性、行为和功能特征将是制定未来监测策略和防范水源性健康风险的必要条件。为了增进理解，本研究调查了在运行管网内从不同管材上形成的生物膜的迁移和积累行为、微生物群落结构和功能变化。在初始水力冲刷三个月后，进行了重复冲洗操作，从四个管道中采集了样本。初始水力冲刷利用水力将再生生物膜从管中移走，但不会影响上游管网。为了减少混杂因素，选择了具有相似日水力条件、物理尺寸、与共同干管的所有直段相连、且水化学、压力和年龄相似的测试段。分类学结果表明，管材上的定植群落存在差异，包括假单胞菌和黑曲霉在内的几个属存在于每个样本中。与真菌（即真菌群落）相比，细菌群落更加多样化。基于操作分类单元（OTU）相对丰度的细菌/真菌网络分析表明，与非铁质管材相比，铸铁管中的微生物群落更加稳定。对所有样本的功能特征分析发现，主要与移动遗传元件有关，这些元件在确定细胞之间的联系中发挥作用，包括噬菌体、前噬菌体、转座元件和质粒。可以考虑将功能特征用于未来监测方法的开发，这些方法能够提供超出有限传统粪便指示物测试的网络状况信息，从而有助于保护水质和公共健康。
