污水地下渗滤系统微生物代谢组学分析

Microbial metabolomics analysis of subsurface wastewater infiltration system

应用超高效液相色谱-质谱技术(UPLC-MS),基于代谢组学方法,筛选不同进水有机负荷下地下渗滤系统潜在生物标志物.采用偏最小二乘法(PLS-DA)和主成分分析(PCA)模式识别方法对样品进行分型处理,根据模型的变量重要性因子(VIP值)筛选潜在生物标志物,分析代谢产物蕴含的生物学信息,研究代谢通路,通过RDA分析探索代谢产物与环境因子之间的相关性.PLS-DA模型结果表明,当进水有机负荷为250mg/L、400mg/L、500mg/L时,同一高度层代谢产物间存在显著性差异,共筛选出VIP值大于1.5的230种差异代谢物,以有机酸为主;同时也存在一些醇类、酚类等微生物代谢中间产物.此外,微生物代谢产物与模拟土柱高度有显著对应性.在水力负荷为0.14m^3/(m^2·d),COD污染负荷为400mg/L条件下,3个高度层H2(500mm)、H4(1000mm)、H6(1500mm)筛选出53种VIP值大于1.5的差异代谢物,以酸类、酮类物质为主.RDA分析表明,随着有机负荷波动和剖面高度的变化,代谢产物受到氧化还原环境(ORP)与硝态氮(NO3-)的影响较大,呈负相关.

Based on metabolomics method,ultra-performance liquid chromatography-mass spectrometry(UPLC-MS)was used to screen potential biomarkers of subsurface infiltration systems under different organic loads.The samples were typed by partial least squares(PLS-DA)and principal component analysis(PCA)pattern recognition methods,and potential biomarkers were screened according to the model's variable importance factor(VIP).Furthermore,biological information involved in metabolites and metabolic pathways were revealed.Finally,correlation between metabolites and environmental factors was explored by RDA analysis.The results of PLS-DA model showed that when the influent organic load gradually increased from 250mg/L to 400mg/L and 500mg/L,there was a significant difference between the metabolites in the same soil profile.A total of 230differential metabolites with a VIP value greater than 1.5 were screened out,which were mainly composed of organic acids,such as lactic acid,tartronic acid,dioleoylphosphatidic acid.The microbial metabolites had a significant correspondence with the soil profile.Under the condition of hydraulic load 0.14m^3/(m^2·d)and COD 400mg/L,53metabolites with a VIP value greater than 1.5 were screened out from H2(500mm),H4(1000mm)and H6(1500mm),respectively,which was mainly composed of acid and ketone substances,such as 6-Hydroxyondansetron sulfate,19-Norandrosterone glucuronide and Methylcarbamyl PAF C-8.The results of RDA suggested that with the variation of pollution load and substrate profile,metabolites were negatively influenced by oxidation reduction potential(ORP)and nitrate(NO3-).