两株假单胞菌对吡啶和喹啉的生物降解(英文)

Biodegradation of pyridine and quinoline by two Pseudomonas strains

【目的】探究2株假单胞菌(Pseudomonas)对吡啶和喹啉的降解。【方法】基于16S rRNA序列同源性和基因间区分析,对分离菌株进行分类鉴定。通过分光光度法和电喷雾电离质谱法(Electrospray Ionisation/Mass Spectrometry,ESI/MS)确定分离菌株对吡啶和喹啉的降解性能。通过质粒消除验证降解质粒的存在,同时克隆了可能的降解基因。【结果】鉴定结果表明,两株分离细菌隶属于Pseudomonas,并将其命名为XJUHX-1和XJUHX-12。降解数据表明,2株菌株分别耐受吡啶和喹啉,同时分别检测到4种和2种吡啶和喹啉的可能降解产物。结果还表明,消除质粒后的菌株对吡啶和喹啉的降解能力降低。扩增的编码NADH还原酶部分的降解喹啉oxoR基因和编码硝酸还原酶的降解吡啶的nifH基因,同时在E.coli中表达了43kDa和16kDa的蛋白。【结论】2株Pseudomonas具有降解吡啶和喹啉的能力。

[Objective] To study the degradation of pyridine and quinoline by two Pseudomonas.[Methods] Based on the analysis of 16S rRNA gene sequence homology and the intergenic spacer region sequence,the two isolates were identified.The degradation capability of pyridine and quinoline was determined according to spectrophotometry and Electrospray Ionisation/Mass Spectrometry（ESI/MS）.The degrading plasmids were detected by plasmid curing and the possible degrading genes were also cloned.[Results] The two isolates were identified as Pseudomonas and nominated XJUHX-1 and XJUHX-12.The two Pseudomonas were tolerant with pyridine and quinoline and two and four possible metabolites were detected in the culture medium containing quinoline and pyridine,respectively.The degrading capability of curing plasmids was lower than the crude isolates.The gene segments coding for the NADH（acceptor） reductase component OxoR for quinoline degradation and nitrogenase reductase（NifH） of denitrification for pyridine degradation were amplified from the genome of XJUHX-1 and XJUHX-12,both were cloned and expressed in E.coli BL 21 producing recombinant proteins with molecular mass of 43 kDa and 16 kDa.[Conclusion] The two isolates could degrade pyridine and quinoline respectively.