Biphenyl-Metabolizing Bacteria in the Rhizosphere of Horseradish and Bulk Soil Contaminated by Polychlorinated Biphenyls as Revealed by Stable Isotope Probing
Biphenyl-Metabolizing Bacteria in the Rhizosphere of Horseradish and Bulk Soil Contaminated by Polychlorinated Biphenyls as Revealed by Stable Isotope Probing
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DOI：
10.1128/aem.00466-09
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发表时间：
2009-08
影响因子：
4.4
通讯作者：
O. Uhlík;K. Jecná;M. Mackova;Č. Vlček;Miluše Hroudová;K. Demnerova;V. Paces;T. Macek
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文献类型：
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作者：
O. Uhlík;K. Jecná;M. Mackova;Č. Vlček;Miluše Hroudová;K. Demnerova;V. Paces;T. Macek
摘要以DNA为基础的稳定同位素探针结合末端限制性片段长度多态性，以确定在根际的辣根（Armoracia rusticana）与多氯联苯（PCBs）污染的土壤中培养的微生物群落的成员相比，在初始，未耕种的散装土壤中的微生物群落的联苯代谢的微生物群落的成员。在[13 C]DNA构建的克隆文库中，对噬氢菌属（Hydrogenophaga spp.）辣根根际土壤中的联苯类抗生素似乎占主导地位，而类芽孢杆菌属。是主要的联苯利用细菌在初始散装土壤。在这项基于营养物修正的微观研究中发现的从联苯中获得碳的其他细菌大多属于β-变形菌纲，并被鉴定为无色杆菌属，Variovorax spp.，食甲基菌属，或嗜甲基菌属（Methylophilus spp.）还检测到一些在属水平上未分类的细菌，这些细菌可能是未描述的属的成员。在含[13 C]联苯的土壤中培养3天后，将[13 C]掺入到DNA中的细菌的联苯双加氧酶α亚基（BphA）的氨基酸序列与产碱假单胞菌B-357的BphA的氨基酸序列几乎相同。这表明，可以被这些酶降解的多氯联苯同系物的光谱可能与菌株B-357的相似。这些结果表明，改变土壤环境可以导致不同的细菌参与联苯的代谢。
ABSTRACT DNA-based stable isotope probing in combination with terminal restriction fragment length polymorphism was used in order to identify members of the microbial community that metabolize biphenyl in the rhizosphere of horseradish (Armoracia rusticana) cultivated in soil contaminated with polychlorinated biphenyls (PCBs) compared to members of the microbial community in initial, uncultivated bulk soil. On the basis of early and recurrent detection of their 16S rRNA genes in clone libraries constructed from [13C]DNA, Hydrogenophaga spp. appeared to dominate biphenyl catabolism in the horseradish rhizosphere soil, whereas Paenibacillus spp. were the predominant biphenyl-utilizing bacteria in the initial bulk soil. Other bacteria found to derive carbon from biphenyl in this nutrient-amended microcosm-based study belonged mostly to the class Betaproteobacteria and were identified as Achromobacter spp., Variovorax spp., Methylovorus spp., or Methylophilus spp. Some bacteria that were unclassified at the genus level were also detected, and these bacteria may be members of undescribed genera. The deduced amino acid sequences of the biphenyl dioxygenase α subunits (BphA) from bacteria that incorporated [13C]into DNA in 3-day incubations of the soils with [13C]biphenyl are almost identical to that of Pseudomonas alcaligenes B-357. This suggests that the spectrum of the PCB congeners that can be degraded by these enzymes may be similar to that of strain B-357. These results demonstrate that altering the soil environment can result in the participation of different bacteria in the metabolism of biphenyl.