高氮负荷下硫自养反硝化菌群的胞外聚合物和信号分子特征  

Characterization of extracellular polymer substances and acyl-homoserine lactones of sulfur-based autotrophic denitrification microbial community under high nitrate loading

作　　者：许炜怡 黄凯文 刘崇 沈斐 王硕 李激 XU Wei-yi;HUANG Kai-wen;LIU Chong;SHEN Fei;WANG Shuo;LI Ji(Jiangsu Key Laboratory of Anaerobic Biotechnology,School of Environment&Ecology,Jiangnan University,Wuxi 214122,China;101 Institute of the Ministry of Civil Affairs,Beijing 100070,China;Laboratory of Instrumental Analysis,Jiangsu Wuxi Environmental Monitoring Center,Wuxi 214121,China;Jiangsu College of Water Treatment Technology and Material Collaborative Innovation Center,Suzhou 215009,China)

机构地区：[1]江南大学环境与生态学院,江苏省厌氧生物技术重点实验室,江苏无锡214122 [2]民政部一零一研究所,北京100070 [3]江苏无锡环境监测中心仪器分析实验室,江苏无锡214121 [4]江苏省高校水处理技术与材料协同创新中心,江苏苏州215009

出　　处：《中国环境科学》2024年第8期4314-4325,共12页China Environmental Science

基　　金：国家重点研发项目(2023YFC3207601);江苏省政策引导类计划(国际科技合作/港澳台科技合作)专项资金(BZ2021030);中央级公益性科研院所基本科研业务费专项(102118220110000009024)。

摘　　要：硫自养反硝化工艺(SADN)受水力停留时间(HRT)和进水NO_(3)^(-)-N浓度的影响.通过逐步缩短HRT,提高进水NO_(3)^(-)-N浓度的方式探究工艺脱氮极限,同时解析在此过程中胞外聚合物(EPS)和信号分子酰基高丝氨酸内酯(AHLs)的变化特征以及微生物群落结构演替过程.在HRT从4.1h缩短至1.0h的过程中,硫自养反硝化菌群可快速适应环境,当HRT=1.0h,进水NO_(3)^(-)-N含量为40mg/L,系统的TN去除率为99.74%,脱氮负荷高达958.53mg/(L·d).在此过程中,EPS含量的增加以TB-PN和TB-PS为主,AHLs含量的增加以C4-HSL为主.较缩短HRT而言,提高进水NO_(3)^(-)-N浓度会促使C4-HSL含量显著增加并导致污泥结构逐渐趋向不稳定状态.C6-HSL是系统内最主要的AHLs,其含量在G4和G7阶段大幅增长是基于系统脱氮能力弱化后微生物所进行的自我调节.微生物群落组成分析表明,系统运行和氮负荷变化会对微生物群落进行驯化选择.在降HRT组中,Proteobacteria的norank_f_Pleomorphomona-daceae作为优势菌属发挥主要作用,为反硝化菌提供底物以维持系统稳定运行.在提高NO_(3)^(-)-N浓度后,UKL 13-1、Simplicispira、Allorhizobium-Neorhizobium-Pararhizobium-Rhizobium、Thermomonas逐渐演变为优势菌属,这些优势菌属均为具备脱氮功能的关键微生物.Sulfur-based autotrophic denitrification(SADN)was influenced by hydraulic retention time(HRT)and influent NO_(3)^(-)-N concentration.By progressively shortening the HRT and increasing the influent NO_(3)^(-)-N concentration,the nitrogen removal limit of the process was explored.Simultaneously,the changes in extracellular polymeric substances(EPS)and signal molecules acyl-homoserine lactones(AHLs)were analyzed,along with the evolution of microbial community structure in this process.During the transition from an HRT of 4.1h to 1.0h,SADN bacteria rapidly adapted to the environment.When the HRT was 1.0h and the influent NO_(3)^(-)-N concentration was 40mg/L,the system achieved a TN removal rate of 99.74%,with a denitrification load as high as 958.53mg/(L·d).In this process,the increase in EPS concentration was mainly driven by TB-PN and TB-PS,while the increase in AHLs concentration was primarily led by C4-HSL.In comparison to shortening the HRT,raising the influent NO_(3)^(-)-N concentration significantly increased the C4-HSL concentration,leading to a gradual trend towards an unstable state in the sludge structure.C6-HSL,the predominant AHL in the system,exhibited substantial growth in stages G4 and G7,reflecting a self-regulation by the microorganisms following the weakening of the system's denitrification capability.Analysis of the microbial community composition indicated that system operation and nitrogen load variations drove the domestication selection of microbial communities.In the reduced HRT group,norank_f_Pleomorphomonadaceae of Proteobacteria played a primary role as the dominant bacterial genus,providing substrates for denitrification bacteria to sustain system stability.Following the increase in NO_(3)^(-)-N concentration,UKL 13-1,Simplicispira,Allorhizobium-Neorhizobium-Pararhizobium-Rhizobium,and Thermomonas gradually evolved into dominant bacterial genera,all crucial microorganisms with denitrification capabilities.

关 键 词：硫自养反硝化 脱氮极限 胞外聚合物 酰基高丝氨酸内酯 群体感应 

分 类 号：X703[环境科学与工程—环境工程]