本文選題：尼古丁　切入點(diǎn)：代謝途徑　出處：《浙江工業(yè)大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

【摘要】：尼古丁是一種會(huì)使人上癮或產(chǎn)生依賴性的生物堿,其進(jìn)入人體會(huì)引起多種疾病,包括肺癌、口腔癌、食道癌、心血管病和胃功能障礙等。我國煙民數(shù)量之多,煙草生產(chǎn)及加工產(chǎn)業(yè)之龐大,產(chǎn)生了大量含高濃度尼古丁的煙草廢棄物,給環(huán)境帶來了極大的安全隱患。微生物作為環(huán)境污染物降解的主力軍,其在環(huán)境修復(fù)中的應(yīng)用一直被認(rèn)為是高效、可靠和環(huán)境友好的。因此,發(fā)現(xiàn)具尼古丁降解功能的微生物,研究其降解特性及機(jī)理,探索其“變廢為寶”的內(nèi)在規(guī)律,是符合我國可持續(xù)性發(fā)展戰(zhàn)略要求的,具有重大的理論意義和應(yīng)用價(jià)值。本研究從杭州一農(nóng)藥廠的活性污泥中篩選得到兩株尼古丁降解菌,并選取其中降解能力更強(qiáng)的菌株作為本次研究的對(duì)象,命名為T2。根據(jù)其生理生化特性及其16S rDNA基因序列同源性分析,鑒定為極小單胞菌(Pusillimonas)。這是在該菌屬里首次發(fā)現(xiàn)具有尼古丁降解能力的菌株。對(duì)T2降解特性的研究結(jié)果顯示菌株T2降解尼古丁的最佳條件為:pH 7.0左右,溫度30℃左右,接種量100%左右,尼古丁初始濃度500 mg/L左右。本研究利用紫外掃描法(UV)、高效液相色譜法(HPLC)和高效液相色譜-質(zhì)譜聯(lián)用法(LC-MS)共檢測(cè)到六種中間代謝產(chǎn)物,分別為6-羥基尼古丁(6HN),6-羥基-N-甲基麥斯明(6HMM),6-羥基假氧化尼古丁(6HPON),6-羥基-3-琥珀酸吡啶(HSP),2,5-二羥基吡啶(2,5-DHP)和2,6-二羥基吡啶(2,6-DHP)。之前未見報(bào)道有中間產(chǎn)物2,5-DHP(吡咯烷途徑產(chǎn)物)和2,6-DHP(吡啶途徑產(chǎn)物)同時(shí)出現(xiàn)在同一菌株代謝過程中,由此我們推測(cè)T2的尼古丁降解途徑可能是一條吡啶-吡咯烷結(jié)合的新途徑。進(jìn)一步的降解實(shí)驗(yàn)顯示,以尼古丁、6HPON或HSP為底物時(shí)降解液的顏色分別為藍(lán)、灰藍(lán)和綠。菌株T2以6HPON作為唯一碳源時(shí),檢測(cè)到產(chǎn)物HSP,2,5-DHP和2,6-DHP。在菌株T2的粗酶液中還分別檢測(cè)到HSP水解酶和2,6-DHP氧化酶活性,酶活性大小分別為0.087和0.012 U/mg蛋白。這些結(jié)果進(jìn)一步證明:T2先將尼古丁降解成6HN,繼而6HN轉(zhuǎn)變?yōu)?HMM,接著6HMM自發(fā)水解生成6HPON,然后6HPON分別通過吡啶途徑和吡咯烷途徑降解成2,6-DHP以及HSP和2,5-DHP。這是一條新型的尼古丁降解途徑,即吡啶-吡咯烷結(jié)合途徑。
[Abstract]:Nicotine is an alkaloid that can be addictive or dependent. Its entry into the body can cause many diseases, including lung cancer, oral cancer, esophageal cancer, cardiovascular disease and gastric dysfunction. The huge production and processing industry of tobacco has produced a large amount of tobacco waste containing high concentration of nicotine, which has brought a great security hazard to the environment. Microbes are the main force in the degradation of environmental pollutants. Its application in environmental remediation has always been considered to be highly efficient, reliable and environmentally friendly. Therefore, microbes with nicotine degradation function are found, their degradation characteristics and mechanisms are studied, and the inherent law of "turning waste into treasure" is explored. In this study, two strains of nicotine degrading bacteria were screened from activated sludge of an agricultural pharmaceutical factory in Hangzhou. The strain with stronger biodegradability was selected as the object of this study, named T2.According to its physiological and biochemical characteristics and the homology analysis of 16s rDNA gene sequence, The strain was identified as Pusillimonasus. This is the first strain with nicotine degradation ability found in the genus Pusillimonas.A study on the degradation of nicotine by T2 showed that the optimum conditions for the degradation of nicotine by strain T2 were about 7. 0 pH and 30 鈩，

本文編號(hào)：1565589