Abstract：
Biofilms, constituting over 95 % of the biomass in drinking water distribution systems, form an ecosystem impacting both the aesthetic and microbiological quality of water. This study investigates the microbiome of biofilms within a real-scale drinking water distribution system in eastern Spain, utilizing amplicon-based metagenomics. Forty-one biofilm samples underwent processing and sequencing to analyze both bacterial and eukaryotic microbiomes, with an assessment of active biomass. Genus-level analysis revealed considerable heterogeneity, with Desulfovibrio, Ralstonia, Bradyrhizobium, Methylocystis, and Bacillus identified as predominant genera. Notably, bacteria associated with corrosion processes, including Desulfovibrio, Sulfuricella, Hyphomicrobium, and Methylobacterium, were prevalent. Potentially pathogenic bacteria such as Helicobacter, Pseudomonas, and Legionella were also detected. Among protozoa, Opisthokonta and Archaeplastida were the most abundant groups in biofilm samples, with potential pathogenic eukaryotes (Acanthamoeba, Naegleria, Blastocystis) identified. Interestingly, no direct correlation between microbiota composition and pipe materials was observed. The study suggests that the usual concentration of free chlorine in bulk water proved insufficient to prevent the presence of undesirable bacteria and protozoa in biofilms, which exhibited a high concentration of active biomass.
摘要：
生物膜,构成饮用水分配系统中超过95%的生物量，形成一个影响水的美学和微生物质量的生态系统。这项研究调查了西班牙东部真实规模的饮用水分配系统中生物膜的微生物组，利用基于扩增子的宏基因组学。41个生物膜样品进行了处理和测序，以分析细菌和真核微生物组，与活性生物量的评估。属水平分析显示出相当大的异质性，与Desulfovibrio，Ralstonia,缓生根瘤菌,Methylocystis,和芽孢杆菌被确定为主要属。值得注意的是,与腐蚀过程相关的细菌，包括Desulfovibrio,Sulfuriicella,微生物,和甲基杆菌，很普遍。潜在的致病细菌，如螺杆菌，假单胞菌,还检测到军团菌。在原生动物中，Opisthokonta和Archaeplastida是生物膜样品中最丰富的群体，具有潜在的致病性真核生物(棘阿米巴，Naegleria,囊胚）鉴定。有趣的是,未观察到微生物群组成与管道材料之间的直接相关性。该研究表明，散装水中游离氯的通常浓度被证明不足以防止生物膜中不良细菌和原生动物的存在，表现出高浓度的活性生物质。
