摘要
自由生活阿米巴(free-living amoebae,FLA)因其对人类健康的潜在威胁及其在水生生态系统中的关键作用,具有重要的研究意义。采取培养学联合分子学的方法探究长江下游一大型自来水厂内部FLA及其胞内菌的分布特征。3次水厂全流程采样共收集样本107份,FLA检出率为39.3%,且FLA主要分布于原水和水厂前端处理工艺单元,水厂出水均未检出FLA,表明该水厂采用的预臭氧-平板沉淀-砂滤-活性炭滤-消毒处理工艺可以有效去除原水带入的FLA,且过滤工艺单元是主要的FLA去除单元。经分离纯化共获得42株FLA,经测序得到28个操作分类单位,归属于Naegleria、 Vermamoeba和Acanthamoeba这3个属。其中,Naegleria为该水厂的优势阿米巴属,而Acanthamoeba和Vermamoeba的水厂分布可能受温度和溶解氧浓度影响。FLA胞内检出Pseudomonas、Bacillus、Paenibacillus、 Escherichia-Shigella、 Aeromonas等潜在的人类致病菌和Comamonas、 Brevibacillus、 Pelomonas、Aquabacterium、Herminiimonas等水环境常见碳氮转化功能菌,其中Pseudomonas、Brevibacillus和Bacillus为该水厂FLA胞内的核心细菌。部分工艺单元中FLA胞内共生的Pseudomonas和Bacillus等潜在致病菌的检出,表明应升级现有水处理工艺以提高耐氯病原微生物去除效能。研究结果可为提高长江流域供水安全提供技术和数据支撑。
Free-living amoebae(FLA)are of crucial importance due to their role as both potential pathogens to human health and key ecological players in aquatic environments.This study employed a combination of culture-based and molecular techniques to investigate the distribution patterns of FLA and their associated intracellular bacteria in a large water treatment plant located in the lower Yangtze River Basin.A total of 107 samples were collected from various stages of the treatment plant during three sampling events.The total positive rate of FLA was 39.3%.FLA were mainly distributed in the raw water and the initial treatment stages,but none FLA were detected in the effluent of the plant,indicating that the pre-ozonation,horizontal sedimentation,sand filtration,activated carbon filtration,and disinfection were effective in removing FLA originating from raw water and other units,with filtration units being the primary FLA removal stages.A total of 42 FLA strains were isolated and purified,and 28 operational taxonomic units(OTUs)were identified after 18s rRNA gene sequencing,which belong to three genera:Naegleria,Vermamoeba and Acanthamoeba.Among them,Naegleria was the dominant amoeba genus in the plant,followed by Acanthamoeba and Vermamoeba.And the distribution of Acanthamoeba and Vermamoeba in the plant may be influenced by temperature and dissolved oxygen concentration.Several potential human pathogenic bacteria,such as Pseudomonas species,Bacillus species,Paenibacillus species,Escherichia-Shigella,and Aeromonas species,as well as environmentally significant bacteria involved in carbon and nitrogen metabolism,such as Comamonas,Brevibacillus,Pelomonas,Aquabacterium,and Herminiimonas,were detected within the cells of isolated FLA.Among them,Pseudomonas,Brevibacillus and Bacillus were the core intracellular bacteria in FLA of the plant.The detection of FLA-harbored pathogenic bacteria(e.g.,Pseudomonas,Bacillus)in water treatment units necessitates plant upgrades to eliminate chlorine-resistant pathogens.The results of this study can provide technical and data support for improving the safety of water supply in the Yangtze River Basin.
作者
董倩芮
田哲
韩子铭
段福明
张辉灿
张昱
杨敏
DONG Qianrui;TIAN Zhe;HAN Ziming;DUAN Fuming;ZHANG Huican;ZHANG Yu;YANG Min(Henan Institute of Advanced Technology,Zhengzhou University,Zhengzhou 450003,China;National Engineering Research Center of Industrial Wastewater Detoxication and Resource Recovery,Research Center for Eco-Environmental Sciences,Chinese Academy of Sciences,Beijing 100085,China;State Key Laboratory of Environmental Aquatic Chemistry,Research Center for Eco-Environmental Sciences,Chinese Academy of Sciences,Beijing 100085,China;Shijiazhuang Saike Environmental Protection Research Institute,Shijiazhuang 050399,China)
出处
《环境工程学报》
北大核心
2025年第10期2414-2425,共12页
Chinese Journal of Environmental Engineering
基金
国家重点研发计划资助项目(2022YFC3204700)
天津市科技计划资助项目(22YFXTHZ00080)。
关键词
自来水厂
自由生活阿米巴
分离培养
胞内菌
water supply plant
free-living amoebae
cultivation
amoeba-intracellular bacteria
