Chemical and genomic analyses of polycyclic aromatic hydrocarbon biodegradation in Sphingobium barthaii KK22 reveals divergent pathways in soil sphingomonads
Chemical and genomic analyses of polycyclic aromatic hydrocarbon biodegradation in Sphingobium barthaii KK22 reveals divergent pathways in soil sphingomonads
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DOI：
10.1016/j.ibiod.2020.104993
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发表时间：
2020-07
影响因子：
4.8
通讯作者：
Allyn H. Maeda;S. Nishi;Y. Hatada;Y. Ohta;Kanna Misaka;Marie Kunihiro;Jiro F. Mori;R. Kanaly
中科院分区：
文献类型：
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作者：
Allyn H. Maeda;S. Nishi;Y. Hatada;Y. Ohta;Kanna Misaka;Marie Kunihiro;Jiro F. Mori;R. Kanaly
多环芳烃（PAHs）是一种可被土壤细菌降解的有害污染物，而土壤鞘单胞菌被认为是多环芳烃生物降解的主要贡献者。为了预测多环芳烃的环境归宿，有必要了解鞘单胞菌生物降解多环芳烃的化学和遗传学。当土壤鞘氨醇单胞菌Sphingobium barthaiiKK 22暴露于低分子量（LMW）多环芳烃时，通过综合化学分析研究其生物转化产物，通过不同的技术鉴定出至少20种产物，并且发现该生物体中的二醇内和二醇外芳香环裂解途径都是活跃的。鞘氨醇单胞菌是一个庞大而多样的类群，其对多环芳烃的生物降解作用已被研究，但对低分子量多环芳烃的二醇环内裂解作用尚未见报道。全基因组测序及预测。barthaiIKK22功能基因揭示了芳香环羟化加氧酶和PAH生物转化基因的集合。结合化学分析结果，构建了新的、接近完整的土壤鞘单胞菌对PAH的生物转化途径。结合定量分析，一个全面的看法PAH生物降解，揭示了不同的下游途径，推进我们的理解，这些多才多艺的土壤细菌的PAH生物转化能力，并应有助于在土壤生物修复过程中的PAH环境命运的预测。
Polycyclic aromatic hydrocarbons (PAHs) are hazardous pollutants that are biodegraded by soil bacteria and the soil sphingomonads are thought to be major contributors to PAH biodegradation. To predict PAH environmental fates it is necessary to understand the chemistry and genetics of PAH biodegradation by sphingomonads. When the soil sphingomonadSphingobium barthaiiKK22 was exposed to low molecular weight (LMW) PAHs and biotransformation products were investigated by comprehensive chemical analyses, at least twenty products were identified by different techniques and both intradiol- and extradiol-aromatic ring cleavage pathways were found to be active in this organism. Sphingomonads, a large and diverse group, have been studied in regard to PAH biodegradation, however intradiol-ring cleavage of LMW PAHs has never been reported. Whole genome sequencing and prediction ofS. barthaiiKK22 functional genes revealed sets of aromatic ring-hydroxylating oxygenases and PAH biotransformation genes. Combined with chemical analyses results, novel, near complete PAH biotransformation pathways for soil sphingomonads were constructed. In conjunction with quantitative assays, a comprehensive view of PAH biodegradation was obtained that revealed divergent downstream pathways that advanced our understanding of the PAH biotransformation capabilities of these versatile soil bacteria and shall aid in predictions of PAH environmental fate during soil bioremediation.