Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University , Jinan, China.
Environ Sci Technol. 2017 Jun 6;51(11):6298-6307. doi: 10.1021/acs.est.7b00188. Epub 2017 May 18.
Genetic bioaugmentation, in which bacteria harboring conjugative plasmids provide catabolic functions, is a promising strategy to restore dioxin-contaminated environments. Here we examined the conjugative transfer of the dioxin-catabolic plasmids pDF01 and pDF02 harbored by Rhodococcus sp. strain p52. A mating experiment using strain p52 as a donor showed that pDF01 and pDF02 were concomitantly and conjugatively transferred from strain p52 to a Pseudomonas aeruginosa recipient at a conjugation frequency of 3 × 10 colonies per recipient. pDF01 and pDF02 were isolated from the P. aeruginosa transconjugant and identified by Southern hybridization, and they were localized in the transconjugant cells by fluorescence in situ hybridization. Moreover, the catabolic plasmids functioned in the transconjugant, which gained the ability to use dibenzofuran and chlorodibenzofuran for growth, and they were maintained in 50% of the transconjugant cells for 30 generations without selective pressure. Furthermore, conjugative transfer of the catabolic plasmids to activated sludge bacteria was detected. Sequencing of pDF01 and pDF02 revealed the genetic basis for the plasmids' conjugative transfer and stable maintenance, as well as their cooperation during dioxin catabolism. Therefore, strain p52 harboring pDF01 and pDF02 has potential for genetic bioaugmentation in dioxin-contaminated environments.
遗传生物增强，其中携带可接合质粒的细菌提供分解代谢功能，是恢复二恶英污染环境的一种很有前途的策略。在这里，我们研究了 Rhodococcus sp. 菌株 p52 携带的二恶英分解代谢质粒 pDF01 和 pDF02 的可接合转移。使用菌株 p52 作为供体的交配实验表明，pDF01 和 pDF02 同时从菌株 p52 到 Pseudomonas aeruginosa 受体以 3×10 个菌落每受体的接合频率进行可接合转移。pDF01 和 pDF02 从 P. aeruginosa 转导子中分离出来，并通过 Southern 杂交鉴定，通过荧光原位杂交将它们定位在转导子细胞中。此外，这些分解代谢质粒在转导子中起作用，转导子获得了利用二苯并呋喃和氯二苯并呋喃进行生长的能力，并且在没有选择压力的情况下，它们在 50%的转导子细胞中维持了 30 代。此外，还检测到这些分解代谢质粒到活性污泥细菌的可接合转移。pDF01 和 pDF02 的测序揭示了质粒可接合转移和稳定维持的遗传基础，以及它们在二恶英分解代谢过程中的合作。因此，携带 pDF01 和 pDF02 的菌株 p52 有可能在二恶英污染环境中进行遗传生物增强。
