<p>Remediation of PAH-contaminated soils is often limited by oxygen delivery, highlighting the importance of organisms that maintain PAH degradation under anoxic conditions. We isolated three <i>Pseudomonas/Stutzerimonas</i> strains on pyrene with nitrate as electron acceptor and confirmed their rapid nitrate-reducing removal of phenanthrene (up to ∼90% in 4 d) and benzo[a]pyrene (up to ∼95% in 5 d), expanding pure-culture evidence for high-molecular-weight PAH degradation under nitrate respiration. Combined with six previously reported facultative anaerobic PAH-degrading <i>Pseudomonas</i> strains, we analyzed nine genomes representing the presently verifiable phenotype-defined subset. Comparative genomics showed an accessory-dominated pan-genome with a strict core (0.07% of 30101 orthogroups), coexistence of diverse aerobic ring-hydroxylation and anaerobic-associated activation (including carboxylation- and methylation- related) genes. Notably, stress resistance genes were present at significantly elevated copy numbers compared to other genes, reflecting adaptive genomic plasticity. The finding that <i>Pseudomonas</i> was the only genus consistently detected across all 17 petroleum-contaminated soils aligns well with the metabolic flexibility and stress-tolerance potential revealed by our phenotypic and genomic analyses. These findings provide a genomic and ecological framework for understanding facultative anaerobic PAH-degrading <i>Pseudomonas</i> strains and support their application in complex, contaminated environments.</p>

错误:搜索内容不能为空,请输入英文关键词
错误:关键词超出字数限制,请精简
高级检索

Integrated strain isolation, comparative genomics, and microbial community analysis reveal metabolic versatility and adaptive strategies of facultative anaerobic PAH-degrading Pseudomonas

  • Nanlan Zhao,
  • Nan Zhou,
  • Zuotao Zhang,
  • Dixiang Wang,
  • Hui Wang

摘要

Remediation of PAH-contaminated soils is often limited by oxygen delivery, highlighting the importance of organisms that maintain PAH degradation under anoxic conditions. We isolated three Pseudomonas/Stutzerimonas strains on pyrene with nitrate as electron acceptor and confirmed their rapid nitrate-reducing removal of phenanthrene (up to ∼90% in 4 d) and benzo[a]pyrene (up to ∼95% in 5 d), expanding pure-culture evidence for high-molecular-weight PAH degradation under nitrate respiration. Combined with six previously reported facultative anaerobic PAH-degrading Pseudomonas strains, we analyzed nine genomes representing the presently verifiable phenotype-defined subset. Comparative genomics showed an accessory-dominated pan-genome with a strict core (0.07% of 30101 orthogroups), coexistence of diverse aerobic ring-hydroxylation and anaerobic-associated activation (including carboxylation- and methylation- related) genes. Notably, stress resistance genes were present at significantly elevated copy numbers compared to other genes, reflecting adaptive genomic plasticity. The finding that Pseudomonas was the only genus consistently detected across all 17 petroleum-contaminated soils aligns well with the metabolic flexibility and stress-tolerance potential revealed by our phenotypic and genomic analyses. These findings provide a genomic and ecological framework for understanding facultative anaerobic PAH-degrading Pseudomonas strains and support their application in complex, contaminated environments.