Institute of Microbiology, Academy of Sciences of the Czech Republic v.v.i., Vídeňská 1083, CZ-142 20 Prague 4, Czech Republic; Department for Innovation in Biological, Agro-food and Forest Systems (DIBAF), University of Tuscia, Via S. Camillo De Lellis, 01100 Viterbo, Italy; Institute for Environmental Studies, Faculty of Science, Charles University in Prague, Benátská 2, CZ-128 01 Prague 2, Czech Republic.
Institute of Microbiology, Academy of Sciences of the Czech Republic v.v.i., Vídeňská 1083, CZ-142 20 Prague 4, Czech Republic.
Sci Total Environ. 2015 Nov 15;533:177-86. doi: 10.1016/j.scitotenv.2015.06.019. Epub 2015 Jul 5.
This study was aimed at complex characterization of three soil samples (bulk soil, topsoil and rhizosphere soil) from a site historically contaminated with polychlorinated biphenyls (PCB). The bulk soil was the most highly contaminated, with a PCB concentration of 705.95 mg kg(-1), while the rhizosphere soil was the least contaminated (169.36 mg kg(-1)). PCB degradation intermediates, namely chlorobenzoic acids (CBAs), were detected in all the soil samples, suggesting the occurrence of microbial transformation processes over time. The higher content of organic carbon in the topsoil and rhizosphere soil than in the bulk soil could be linked to the reduced bioaccessibility (bioavailability) of these chlorinated pollutants. However, different proportions of the PCB congener contents and different bioaccessibility of the PCB homologues indicate microbial biotransformation of the compounds. The higher content of organic carbon probably also promoted the growth of microorganisms, as revealed by phospholipid fatty acid (PFLA) quantification. Tag-encoded pyrosequencing analysis showed that the bacterial community structure was significantly similar among the three soils and was predominated by Proteobacteria (44-48%) in all cases. Moreover, analysis at lower taxonomic levels pointed to the presence of genera (Sphingomonas, Bulkholderia, Arthrobacter, Bacillus) including members with reported PCB removal abilities. The fungal community was mostly represented by Basidiomycota and Ascomycota, which accounted for >80% of all the sequences detected in the three soils. Fungal taxa with biodegradation potential (Paxillus, Cryptococcus, Phoma, Mortierella) were also found. These results highlight the potential of the indigenous consortia present at the site as a starting point for PCB bioremediation processes.
本研究旨在对历史上受到多氯联苯（PCB）污染的三个土壤样品（原状土、表土和根际土）进行复杂的特征描述。原状土污染最严重，PCB 浓度为 705.95mg/kg，而根际土污染最轻（169.36mg/kg）。所有土壤样品中均检测到 PCB 降解中间产物，即氯苯甲酸（CBA），这表明随着时间的推移，微生物转化过程一直在发生。表土和根际土中的有机碳含量高于原状土，这可能与这些氯化污染物的生物可利用性降低有关。然而，不同比例的 PCB 同系物含量和不同的 PCB 同系物生物可利用性表明化合物发生了微生物生物转化。较高的有机碳含量可能也促进了微生物的生长，这一点可以通过磷脂脂肪酸（PFLA）定量来揭示。标签编码焦磷酸测序分析表明，三种土壤的细菌群落结构非常相似，所有情况下都以变形菌门（Proteobacteria）为主（44-48%）。此外，在较低的分类学水平上的分析表明，存在具有报道的 PCB 去除能力的属（Sphingomonas、Bulkholderia、Arthrobacter、Bacillus）。真菌群落主要由担子菌门和子囊菌门组成，占三种土壤中检测到的所有序列的>80%。还发现了具有生物降解潜力的真菌类群（Paxillus、Cryptococcus、Phoma、Mortierella）。这些结果突出了该地点存在的土著菌群作为 PCB 生物修复过程起点的潜力。
