【摘要】 从烟草种植土壤中分离可降解尼古丁的菌株并分析其降解特性。通过形态学观察和分子生物学方法分离、鉴定菌株，利用单因素试验方法确定最适发酵条件和降解率，并利用色谱分离技术检测降解过程中的主要代谢产物，最后采用基因工程手段分析尼古丁降解的关键基因。筛选到1株具有尼古丁稳定降解能力的细菌，经鉴定为嗜水气单胞菌（Aeromonas hydrophila）,命名为AH2016菌株。该菌株在最适生长条件(尼古丁质量浓度2 g·L^-1,温度30℃,pH 6.0)下培养16 h即可降解90%的尼古丁(初始尼古丁的质量浓度为2 g·L^-1),表现出较强的尼古丁降解活性。且AH2016菌株的中间代谢产物在310 nm处未出现吡咯途径特有的6-羟基-3琥珀酰吡啶吸收峰，与假单胞菌属的降解途径不同。最后筛选出一个具有降解尼古丁能力的阳性克隆子AH2016-Y,并初步推测出尼古丁降解的相关基因。更多还原

【Abstract】 Nicotine-degrading strain was isolated from tobacco growing soil by conventional separation method, and identified by morphology observation and molecular biology method. Then its optimal fermentation condition and degradation rate were analyzed via single factor experiment, and the main metabolites during the degradation were separated and detected by chromatography. The key gene involved in nicotine degradation was further analyzed by genetic engineering approaches. The results showed that a bacterial strain（AH2016） with stable degradation ability of nicotine was screened and identified as Aeromonas hydrophila. Under the optimal growth condition, the strain could degrade 90% nicotine(initial concentration of 2 g·L^-1) after 16 h, showing high nicotine degradation activity. Moreover, the intermediate metabolites of strain AH2016 did not show the typical absorption peak of 6-hydroxy-3-succinylpyridine at 310 nm, which was different from the reported degradation pathway of Pseudomonas for nicotine so far. Finally, a positive clone AH2016-Y with nicotine-degrading ability was selected, together with preliminarily speculated genes related to nicotine degradation.更多还原