【背景】烟草在生产和加工中会产生高浓度的尼古丁废弃物，对环境造成较大的污染。【目的】筛选降解尼古丁的微生物菌种并解析其降解尼古丁的代谢途径，理解微生物如何降解尼古丁。【方法】用常规分离筛选方法、结合形态学观察和分子鉴定手段分离和鉴定菌株类别，进而利用单因素试验方法，通过设置不同的尼古丁浓度、温度和pH确定菌株降解尼古丁的最适发酵条件和降解率，利用气相色谱-质谱联用技术检测菌株在尼古丁降解过程中的主要代谢产物。【结果】获得一株以尼古丁为唯一碳源和氮源的节杆菌属(Arthrobacter)菌株，编号为D4；该菌株降解尼古丁的最适温度和pH分别为30.0℃和7.0；在1 g/L的尼古丁浓度下具备较快的尼古丁降解速率，培养18 h时尼古丁降解率可达到90%以上；尼古丁浓度≥4 g/L时菌株生长受到明显抑制；与目前报道的节杆菌属降解途径不同，该菌株降解尼古丁过程中产生了新的终产物N-甲基吡咯烷酮、可替宁及中间产物麦斯明。【结论】本研究分离鉴定到一株具有较快尼古丁降解速率的节杆菌，该菌株很可能存在新的尼古丁降解途径。
[Background] High concentrations of nicotine waste are generated during the production and processing of tobacco, causing serious environmental pollution. [Objective] The purpose of this study is to screen out the microbial strain capable of degrading nicotine, and analyze the metabolic pathways of the strain in nicotine degradation. [Methods] We employed the conventional method for strain isolation and identified the target strain based on morphological characteristics and molecular evidence. The fermentation conditions including nicotine concentration, temperature, and pH were optimized by single factor tests with degradation rate as the indicator. The main metabolites of the strain in nicotine degradation were detected by gas chromatography-mass spectrometry. [Results] Arthrobacter sp. D4 was isolated, which could utilize nicotine as the sole carbon and nitrogen source. The optimal conditions of the strain for degrading nicotine were 30.0℃, pH 7.0, and nicotine concentration of 1 g/L, under which the degradation rate reached 90% within 18 h. The growth of the strain was significantly inhibited when the concentration of nicotine in the culture medium was greater than or equal to 4 g/L. Subsequent experiments revealed that the strain produced new end-products N-methylpyrrolidone and cotinine and the intermediate product myosmine, which were different from the reported degradation pathway of Arthrobacter sp. [Conclusion] In this study, an Arthrobacter sp. strain characterized by fast nicotine degradation was isolated and identified. Moreover, this strain may have a new nicotine degradation pathway.
邓帅军,张鸽,刘德水,貊志杰,史素娟,李志豪,马莉,刘晓晖,张海波,刘好宝,王倩.一株尼古丁降解菌株Arthrobacter sp. D4的分离鉴定及其降解代谢途径[J].微生物学通报,2022,49(9):3644-3656复制