A comprehensive understanding of the molecular mechanisms underlying microbial catabolism of dibutyl phthalate (DBP) is still lacking. Here, we newly isolated a bacterial strain identified as PS1 with high efficiency of DBP degradation. The degradation ratios of DBP at 100–1000 mg/L by this strain reached 80–99 % within 72 h without a lag phase. A rare DBP-degradation pathway containing two monobutyl phthalate-catabolism steps was proposed based on intermediates identified by HPLC-TOF-MS/MS. In combination with genomic and transcriptomic analyses, we identified 66 key genes involved in DBP biodegradation and revealed the genetic basis for a new complete catabolic pathway from DBP to Succinyl-CoA or Acetyl-CoA in the genus for the first time. Notably, we found that a series of homologous genes in and clusters were simultaneously activated under DBP exposure and some key intermediate degradation related gene clusters including , , , , and exhibited a favorable coexisting pattern, which contributed the high-efficient DBP degradation ability and strong adaptability to this strain. Overall, these results broaden the knowledge of the catabolic diversity of DBP in microorganisms and enhance our understanding of the molecular mechanism underlying DBP biodegradation.

中文翻译：

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基于生化和多组学方法对铜绿假单胞菌 PS1 中邻苯二甲酸二丁酯分解代谢的分子见解

目前仍缺乏对邻苯二甲酸二丁酯（DBP）微生物分解代谢分子机制的全面了解。在这里，我们新分离出了一株具有高效降解 DBP 的菌株，命名为 PS1。该菌株对 100–1000 mg/L 的 DBP 的降解率在 72 h 内达到 80–99%，无滞后期。基于 HPLC-TOF-MS/MS 鉴定的中间体，提出了一种包含两个邻苯二甲酸单丁酯分解代谢步骤的罕见 DBP 降解途径。结合基因组和转录组分析，我们鉴定了参与DBP生物降解的66个关键基因，并首次揭示了该属中从DBP到琥珀酰辅酶A或乙酰辅酶A的新完整分解代谢途径的遗传基础。值得注意的是，我们发现 和 簇中的一系列同源基因在 DBP 暴露下同时被激活，并且一些关键的中间降解相关基因簇（包括 、 、 、 、 ）表现出良好的共存模式，这贡献了高效的 DBP 降解能力和强大的性能。对这种菌株的适应性。总的来说，这些结果拓宽了微生物中 DBP 分解代谢多样性的知识，并增强了我们对 DBP 生物降解分子机制的理解。