一株高效烟碱降解内生菌的分离及降解特征研究

为了解烟草内生菌的烟碱降解机制，以一株具有高效烟碱降解功能的内生菌G16为对象，通过降解培养及代谢产物分析，对其烟碱降解特征进行研究。结果表明，该菌株经鉴定为Rhizobium sp.G16，在烟碱培养基中的生长符合Slogistic模型，烟碱对G16菌株的最大生长抑制浓度为4000 mg/L；G16菌株的烟碱降解受到pH、接种量及烟碱浓度的影响，其降解过程可采用一级动力学模型进行描述；对G16菌株降解烟碱的中间代谢产物进行分析，发现主要为尼古丁提林、3-（3，4-dihydro-2H-pyrrol-5-yl） pyridine、脱甲基尼古丁、2，3-联吡啶、可铁宁等物质。

Isolation and Degradation Characteristics of an Entophytic Nicotine-degrading Bacterial Strain in Tobacco

In order to understand the nicotine-degrading mechanisms of tobacco endophytes, an endophytic bacterial strain G16 with a high efficiency nicotine-degrading capability was chosen, and its nicotinedegrading characteristics were studied through the methods of nicotine degradation culture and metabolite analysis. The results showed that the strain G16 was identified as Rhizobium sp.G16 and its growth in nicotine medium could be fitted well by the Slogistic model. The growth inhibition concentration of nicotine for strain G16 was 4000 mg/L. The nicotine degradation capability of strain G16 was affected by pH value, inoculation amount of bacterium, and nicotine concentration of broth. Moreover, the results of metabolite analysis by GC-MS showed that the intermediate products of G16 nicotine degradation included nicotyrine, 3-(3,4-dihydro-2H-pyrrol-5-yl) pyridine, nornicotine, cotinine, and so on.