淬灭酶对亚硝化-混合自养脱氮系统的影响

Effect of quenching enzymes on partial nitrification-mixed autotrophic nitrogen removal system

群体感应是微生物间的通信机制,群体淬灭则可通过降解群体感应信号分子来调控微生物行为。本研究通过设置空白对照组R1和实验组R2,探究了群体感应淬灭酶(AHLs酰基转移酶,2μmol/L)对亚硝化-混合自养脱氮工艺性能及微生物群落的影响。结果表明,淬灭酶的加入促进了短程内源反硝化过程并抑制了厌氧氨氧化过程。与R1相比,R2各阶段的总氮去除率平均降低11.1%。R2出水中氨氮和硝氮浓度略低于R1,但出水亚硝氮整体较R1升高19.0mg/L。添加群体淬灭酶使胞外聚合物的含量降低了18.2mg/g,使溶解性微生物产物升高了17.1mg/L。2μmol/L淬灭酶使羟胺氧化还原酶活性由0.80EU/g增长为0.99EU/g,细胞色素c(Heme-c)含量由0.002mmol/g增至0.004mmol/g,Nitrosomonas亚硝化菌和Hyphomicrobium、Thermomonas、Truepera等反硝化菌相对丰度均增加,其中Thermomonas的相对丰度增长幅度最大,由0.28%增长至9.04%。实验结果为群体淬灭技术应用于亚硝化-混合自养脱氮过程的调控提供了理论参考。

Quorum sensing is one kind of communication mechanism between the microorganisms,while quorum quenching can regulate microbial behavior by degrading quorum sensing signaling molecules.In this study,the effects of quorum quenching enzyme(AHLs acyltransferase,2μmol/L)on the performance and microbial characteristics of partial nitrification-mixed autotrophic nitrogen removal process were investigated by adopting blank control group R1 and experimental R2.The results showed that the addition of quenching enzyme promoted the partial endogenous denitrification process but inhibited the anammox process.Compared with R1,the nitrogen removal in R2 was always around 11.1%or lower.The concentration of ammonia and nitrate in the effluent of R2 was slightly lower than those of R1,but the effluent nitrite was 19.0mg/L higher than that of R1.The addition of quorum quenching enzyme reduced the content of extracellular polymeric substances by 18.2mg/g,and increased the soluble microbial products by 17.1mg/L.Compared with R1,2μmol/L quenching enzyme increased the hydroxylamine oxidoreductase activity from 0.80EU/g to 0.99EU/g,and elevated the content of Heme-c from 0.002mmol/g to 0.004mmol/g.The relative abundance of Nitrosomonas,Hyphomicrobium,Thermomonas and Truepera all increased.The Thermomonas presented the highest increase,which rose to 9.04% from 0.28%.The experimental results provide a theoretical reference for the application of quorum quenching technology to the regulation of partial nitrification-mixed autotrophic nitrogen removal process.