愈创木基丙三醇-β-愈创木基醚对土壤中多环芳烃的归趋的影响及微生物群落效应的研究

Study on the Effects of Guaiacylglycerol-β-guaiacyl Ether on the Fate of Polycyclic Aromatic Hydrocarbons and Microbial Community in Soils

[目的]通过培养试验研究多环芳烃的归趋及降解过程的微生物共代谢机制。[方法]以木质素的一种单体模型愈创木基丙三醇-β-愈创木基醚(GGE)为基质底物、多环芳烃BaA为模式污染物,结合同位素示踪和选择性抑制等技术,设立微宇宙培养试验,采用定量PCR技术和扩增子测序等方法来分析GGE对BaA的归趋的影响及其微生物群落效应。[结果]在培养过程中,加入GGE作为底物基质,未能显著提升处理组的矿化率。定量PCR和高通量测序结果表明,GGE的加入改变了土壤微生物群落,且GGE对细菌群落的影响大于真菌群落。相比于对照,GGE处理组增加了细菌群落中α-变形菌纲、拟杆菌门的相对丰度,而β-变形菌纲和芽单胞菌门有所减少;增加了真菌群落中子囊菌门的相对丰度,而担子菌门的相对丰度有所减少。LEfSe分析表明,GGE的添加促进了Hyphomicrobiaceae、Rhodospirillaceae、Acidobacteriaceae、Burkholderiaceae等细菌科和子囊菌门等真菌的富集。[结论]GGE的添加在一定程度上提升了降解过程中真菌的贡献率。底物基质的添加可能会引起多环芳烃的不同微生物降解机制,促进真菌和细菌的协同作用。GGE的添加还富集了一些PAHs潜在降解菌,这些微生物的富集可能会在整体上提升芳香族化合物的代谢功能,增强土壤对多环芳烃类污染物的降解能力。

[Objective]The fate of PAHs and the mechanism of microbial cometabolism in degradation process were studied by microcosm experiment.[Method]Using GGE,a monomer model of lignin,as the matrix substrate and polycyclic aromatic hydrocarbon BaA as the model pollutant,combined with techniques such as isotope tracing and selective suppression,a microcosmic culture experiment was established,using quantitative PCR technology and expansion methods such as amplicon sequencing are used to analyze the influence of GGE on the fate of BaA and its microbial community effect.[Result]During the incubation,adding GGE as the substrate matrix failed to significantly increase the mineralization rate of the treatment group.The quantitative PCR and high-throughput sequencing results showed that the addition of GGE changed the soil microbial community,and GGE had a greater impact on the bacterial community than the fungal community.Compared with the control,the GGE treatment increased the relative abundance of Alpha-proteobacteria and Bacteroides in the bacterial community,while Beta-proteobacteria and Bacillus phylum decreased.The relative abundance of ascomycetes had increased in the fungal community,while the basidiomycetes decreased.LEfSe analysis showed that the addition of GGE promoted the enrichment of bacteria such as Hyphomicrobiaceae,Rhodospirillaceae,Acidobacteriaceae,Burkholderiaceae,and promoted fungi such as Ascomycota.[Conclusion]The addition of GGE increased the contribution rate of fungi in the degradation process to a certain extent.The addition of substrate matrix may cause different microbial degradation mechanisms of PAHs.It also could promote the synergy of fungi and bacteria.The addition of GGE also enriched some potential PAHs degradation microorganism.The enrichment of these bacterial genera may enhance the overall metabolism of aromatic compounds and enhance the ability of soil to degrade PAHs.