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一些根表细菌生物膜具有促进植物生长,提高植物抗逆性以及降解根际有机污染物等生态功能。明确多环芳烃(PAHs)污染条件下根表成膜细菌的群落结构,有助于从植物根表分离筛选出具有PAHs降解功能的成膜细菌,规避植物PAHs污染风险。从长期受PAHs污染的场地采集了距污染源不同距离的土壤和植物(车前草(Plantago depressa Willd)和狗尾巴草(Setaria viridis(L.)Beauv))样品,全面分析了供试样品中PAHs的含量,并利用PCR-DGGE(Polymerase Chain Reaction-Denaturing Gradient Gel Electrophoresis)技术探究了不同PAHs污染强度下根表成膜细菌的群落结构。结果表明,在土壤和植物样品中共检出7种PAHs,车前草和狗尾巴草体内PAHs的种类和浓度各不相同,但其总PAHs含量均远大于土壤中总PAHs的含量。PAHs污染条件下,车前草根表细菌的主要类群为变形杆菌门(Proteobacteria)、放线菌门(Actinobacteria)和厚壁菌门(Firmicutes),狗尾巴草根表的细菌类群主要为变形杆菌门(Proteobacteria),放线菌门(Actinobacteria)、厚壁菌门(Firmicutes)和拟杆菌门(Bacteroidetes)。车前草和狗尾巴草根表成膜细菌的群落结构具有一定的差异性,且其多样性随着PAHs污染强度的增加而逐渐降低,同时其种类及优势菌群也发生较大改变,但一些优势类群如变形杆菌门(Proteobacteria)在不同PAHs污染强度下皆存在且占有重要比例,推测这些类群中的细菌可以利用PAHs为碳源生长或是具备PAHs降解功能。
Some root-surface bacterial biofilms have ecological functions such as promoting plant growth, enhancing plant stress resistance, and degrading rhizosphere organic pollutants. A clear polycyclic aromatic hydrocarbons (PAHs) contaminated conditions under the surface of the membrane-forming bacteria community structure, help to plant from the root surface of the separation and screening of PAHs degrading function of the membrane-forming bacteria to avoid plant PAHs contamination risk. Soil samples and plants (Plantago depressa Willd and Setaria viridis (L.) Beauv) collected at different distances from the sources of contamination were collected from sites contaminated by PAHs for a long time. A comprehensive analysis of PAHs The PCR-DGGE (Polymerase Chain Reaction-Denaturing Gradient Gel Electrophoresis) was used to investigate the community structure of root-forming bacteria under different PAHs pollution intensity. The results showed that seven kinds of PAHs were detected in soils and plant samples. The species and concentrations of PAHs in plantain and tailgrass were different, but the total PAHs contents were much larger than the total PAHs in soil. Under the condition of PAHs pollution, the main groups of epiphytic bacteria in the plantago are Proteobacteria, Actinobacteria and Firmicutes, Proteobacteria, Actinobacteria, Firmicutes and Bacteroidetes. The community structure of plant-forming bacteria in plantain and pakistan grass root has some differences, and its diversity decreases with the increase of pollution intensity of PAHs, and its species and dominant flora also change greatly, but some The dominant groups, such as Proteobacteria, are present and occupy a significant proportion of the PAHs with different PAHs concentrations. It is speculated that the bacteria in these groups can utilize PAHs for carbon source growth or PAHs degradation.