基于活性微生物特征的供水管壁生物膜生长特性

管网生物膜由各种活性微生物、微生物残体及有机无机杂质组成,管网生物膜的生长会导致机会致病菌寄居、管道腐蚀以及水质恶化等系列饮用水卫生问题.为研究供水管壁生物膜形成过程和附着生长活性微生物的分布特征,采用异养菌平板计数(HPC)、流式细胞术(FCM)和16S rRNA高通量测序对3种典型室内供水管材:聚氯乙烯(PVC)、无规共聚聚丙烯(PPR)、不锈钢(STS)内壁活性微生物的生长特性和群落多样性进行了分析.结果表明,PVC管壁生物量在第73 d最先达到峰值,3种管材内壁单位面积最大生物量、生物膜成熟时期生物量均呈现PVC PPR STS的规律. 3种管材表面活性细菌群落结构组成上,PVC管表面主要以硝化螺旋菌门为主,PPR和STS管以疣微菌门为主,其中STS管壁上生物膜物种丰富度最低、多样性最小,群落结构最简单. PVC和PPR管内壁表面相较STS管存在更多的蓝藻细菌和放线菌,在饮用水输配过程中更易引发饮用水嗅味问题.管材介质对管壁生物膜上微生物群落结构存在一定影响.

Growth Features of Water Supply Pipeline Biofilms Based on Active Microorganisms

Biofilm in the water distribution system is composed of various active microorganisms, microbial residues, and organic and inorganic impurities. The growth of pipeline biofilms causes several drinking water hygiene problems, such as the colonization of opportunistic pathogens, corrosion of pipelines, and deterioration of water quality. To investigate the biofilm formation process and the distribution characteristics of live microorganisms attached to drinking water pipe walls, heterotrophic plate count (HPC), flow cytometry (FCM), and high-throughput 16S rRNA sequencing were analyzed to examine the growth characteristics and diversity of active microorganisms on the wall of three typical building water supply pipeline materials:polyvinyl chloride (PVC), polypropylene random (PPR), and stainless steel (STS). The results showed that after 73 d, the biomass on the PVC pipe wall was firstly up to peak. The relationships between the maximum biomass and mature biofilm biomass per unit area among the three pipelines were both PVC > PPR > STS. Regarding the composition and structure of the biofilm active bacterial community on the three different pipelines, the predominant phylum on PVC was Nitrospirae, while Verrucomicrobia was predominant on PPR and STS. The species richness and diversity of biofilm on STS were smallest, and thus the community structure was the simplest. Compared to STS, there were more Cyanobacteria and Actinomycetes on PVC and PPR-hence, odor is more likely to be an issue. The results demonstrated that pipe material can affect the community structure of the attached biofilm.