Wang Xu, Wu Yanan, Chen Meng, Fu Changai, Xu Hangzhou, Li Li
Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, 72 Binhai Road, Qingdao 266237, China.
Marine Genomics and Biotechnology Program, Institute of Marine Science and Technology, Shandong University, 72 Binhai Road, Qingdao 266237, China.
Microorganisms. 2024 Aug 17;12(8):1700. doi: 10.3390/microorganisms12081700.
Microorganisms harbor catabolic plasmids to tackle refractory organic pollutants, which is crucial for bioremediation and ecosystem health. Understanding the impacts of plasmids on hosts provides insights into the behavior and adaptation of degrading bacteria in the environment. Here, we examined alterations in the physiological properties and gene expression profiles of sp. strain p52 after losing two conjugative dioxin-catabolic megaplasmids (pDF01 and pDF02). The growth of strain p52 accelerated after pDF01 loss, while it decelerated after pDF02 loss. During dibenzofuran degradation, the expression levels of dibenzofuran catabolic genes on pDF01 were higher compared to those on pDF02; accordingly, pDF01 loss markedly slowed dibenzofuran degradation. It was suggested that pDF01 is more beneficial to strain p52 under dibenzofuran exposure. Moreover, plasmid loss decreased biofilm formation, especially after pDF02 loss. Transcriptome profiling revealed different pathways enriched in upregulated and downregulated genes after pDF01 and pDF02 loss, indicating different adaptation mechanisms. Based on the transcriptional activity variation, pDF01 played roles in transcription and anabolic processes, while pDF02 profoundly influenced energy production and cellular defense. This study enhances our knowledge of the impacts of degradative plasmids on native hosts and the adaptation mechanisms of hosts, contributing to the application of plasmid-mediated bioremediation in contaminated environments.
微生物携带分解代谢质粒以应对难降解有机污染物，这对生物修复和生态系统健康至关重要。了解质粒对宿主的影响有助于深入了解降解细菌在环境中的行为和适应性。在此，我们研究了sp. 菌株p52在丢失两个接合性二恶英分解代谢大质粒（pDF01和pDF02）后生理特性和基因表达谱的变化。pDF01丢失后，菌株p52的生长加速，而pDF02丢失后生长减速。在二苯并呋喃降解过程中，pDF01上二苯并呋喃分解代谢基因的表达水平高于pDF02上的；因此，pDF01的丢失显著减缓了二苯并呋喃的降解。结果表明，在二苯并呋喃暴露条件下，pDF01对菌株p52更有益。此外，质粒丢失减少了生物膜形成，尤其是在pDF02丢失后。转录组分析揭示了pDF01和pDF02丢失后上调和下调基因中富集的不同途径，表明存在不同的适应机制。基于转录活性变化，pDF01在转录和合成代谢过程中发挥作用，而pDF02对能量产生和细胞防御有深远影响。本研究增进了我们对降解性质粒对天然宿主的影响以及宿主适应机制的认识，有助于质粒介导的生物修复在污染环境中的应用。
