焦化厂PAHs污染土壤中微生物群落多样性特征

Characteristics of microbial community diversity in PAHs contaminated soil of a coking plant

土壤中微生物在多环芳烃(PAHs)的降解过程中起着重要作用。以华北某焦化厂土壤为研究对象,在5个采样点(每个点分6层)采集30个土壤样品,分析土壤环境因子(理化性质和PAHs浓度)、微生物丰度及群落结构,探讨土壤中微生物组成与环境因子间的关系。结果表明:土壤中细菌丰度为5.33~8.89,与土壤深度呈显著负相关(P<0.01),与土壤PAHs、有机碳、全氮浓度呈正相关(P<0.05);土壤中优势细菌类群(门)为变形菌门(Proteobacteria),其相对丰度占比最高达90%,其次是绿弯菌门(Chloroflexi)、放线菌门(Actinobacteria)、厚壁菌门(Firmicutes)和酸杆菌门(Acidobacteria),其占门水平分类细菌数量的64%~97%;细菌类群与环境因子冗余分析表明,焦化厂土壤中细菌群落结构特征是PAHs污染和环境因子共同作用的结果,其中土壤pH与速效钾、PAHs、全氮浓度对土壤细菌群落组成影响明显,PAHs潜在降解菌Proteobacteria丰度与PAHs、全氮、有效磷、速效钾、有机碳浓度呈正相关。

Soil microorganism plays an important role in the degradation of polycyclic aromatic hydrocarbons(PAHs).Taking the soil of a coking plant in North China as the research object,30 soil samples were collected at 5 sampling sites(each site was divided into 6 layers).Soil environmental factors(physical and chemical properties and PAHs concentration),microbial abundance and community structure were analyzed,and the relationship between soil microbial composition and soil environmental factors was discussed.The results showed that the abundance of bacteria in soil ranged from 5.33 to 8.89,which was significantly negatively correlated with soil depth(P<0.01),and positively correlated with soil PAHs,organic carbon and total nitrogen concentrations(P<0.05).The dominant bacteria group(phyla)in the soil was Proteobacteria,whose relative abundance accounted for up to 90%,followed by Chloroflexi,Actinobacteria,Firmicutes and Acidobacteria,which accounted for 64%-97%of the bacteria in the level classification of phyla.Redundancy analysis of bacteria groups and environmental factors showed that the soil bacterial community structure in the coking plant was the result of the combination of PAHs pollution and environmental factors.Soil pH,available potassium,PAHs and total nitrogen content had the most obvious effects on soil bacterial community composition.Abundance of Proteobacteria(a potential PAHs degrading bacterium)was positively correlated with PAHs,total nitrogen,available phosphorus,available potassium and organic carbon content.