【摘要】 目的在前期发现实验室保存的铜绿假单胞菌PAO1具有较强的菲、萘降解能力基础上,对该菌株的菲、萘降解特性及代谢产物进行研究和分析。方法在MM基础培养基中通过改变各种因素来确定PAO1降解的最适条件,应用TLC和HPLC等方法确定了PAO1降解菲、萘过程中存在的重要代谢产物。结果 PAO1对菲、萘的最适降解温度为37℃,最适降解pH值为7.0,对菲、萘的降解属于好氧途径,添加表面活性剂或通过添加低抑制浓度抗生素而增加生物表面活性剂鼠李糖脂的产生都可增加菲、萘的降解,后者效果更好。初步推测PAO1的菲降解存在水杨酸途径和邻苯二甲酸途径;萘降解过程存在水杨酸途径,不存在龙胆酸途径。结论对后续降解途径的进一步清晰以及在此基础上降解酶的确定和工程菌株的构建奠定了基础。更多还原

【Abstract】 Aim Previous study has revealed that Pseudomonas aeruginosa PAO1 could degrade phenanthrene and naphthalene effectively.In this study,the culture conditions for degradation were optimized and the phenanthrene and naphthalene degradation pathways in PAO1 had been investigated.Methods The characteristics of PAHs degradation by PAO1 were determined by changing the growth conditions in MM medium.TLC and HPLC were used to analyse the degradation pathway and products.Results The optimized conditions for phenanthrene and naphthalene degradation by PAO1 were 37℃,pH 7.0 in aerobic environment.Presence of surfactant Tween-80 at 0.1~0.2 g/L and subinhibitory concentrations of tetracycline and vancomycin could facilitate the degradation process.The antibiotic effect was possibly due to their effect on biosurfactant-rhamnolipid production.The production of rhamnolipid was enhanced by subinhibitory concentrations of these two antibiotics.The phenanthrene degradation pathway in PAO1 involved both salicylic acid pathway and phthalic acid pathway while naphthalene degradation involved only the salicylic acid pathway.Conclusion The results expand the further study on the subsequent degradation pathway and build the foundation for the identification of bottleneck degrading enzymes and construction of engineering strains.更多还原