【摘要】：菲是一種具有三個苯環(huán)結構的多環(huán)芳烴(PAHs),化學性質(zhì)穩(wěn)定且疏水性強,能持久的存在于受煤、石油等化石原料污染的土壤、水體和空氣中,并通過食物鏈向人體富集使人體細胞產(chǎn)生癌變。目前,微生物法修復環(huán)境中多環(huán)芳烴污染受到廣泛關注,特別是多環(huán)芳烴高效降解菌的篩選成為研究的熱點。因此,本研究從焦化廢水處理廠回流污泥中取樣,通過馴化、篩選得到一株菲高效降解菌株,通過菌株的形態(tài)觀察、生理生化特性及16S rDNA序列測定對其進行鑒定,并采用響應面法優(yōu)化了菌株的生長條件,同時借助GC-MS、高效液相色譜、傅里葉紅外光譜等分析手段考察了菌株對菲的降解特性及降解途徑。結果如下:(1)從焦化廢水處理廠回流污泥中篩選出1株能以菲為唯一碳源和能源生長的高效降解細菌,命名為P-1。形態(tài)觀察表明該菌株為革蘭氏陽性菌,菌落呈淡黃色、圓形、邊緣整齊、呈半球狀高凸,表面光滑濕潤;菌體較小,呈短桿狀單個排列,菌體大小約為0.2~0.3×0.5~0.8μm。16S rDNA鑒定結果表明菌株P-1可能為鞘脂菌屬。(2)通過單因素實驗、Plackett-Burman實驗、最陡爬坡實驗及響應面實驗優(yōu)化了菌株的最佳生長條件,即溫度為33℃、pH為7.3、裝液量為36ml。此條件下菌株生長量預測值為0.602(OD600),驗證實驗生長量為0.613(OD600),實際值與預測值基本一致。(3)在菌株最佳生長條件下處理含菲廢水,14d后對濃度為1000mg/L的菲的降解率達到99.99%;向廢水中加入1g/L的表面活性劑Tween-80,經(jīng)過6d處理,菲的降解率達到99.75%,是未添加Tween-80時降解速率的2.3倍;向培養(yǎng)基中加入其它多環(huán)芳烴與菲共基質(zhì),萘的加入使菌株對菲的降解率降低41.7%,蒽的加入使菲降解率提高12.65%,而三者同時存在時菲降解率降低22.82%。(4)菌株P-1能以萘、水楊酸、鄰苯二酚為唯一碳源和能源生長,GC-MS和高效液相色譜分析表明,菲降解的中間產(chǎn)物有水楊酸和鄰苯二甲酸,可推測菌株P-1對菲的降解同時具有水楊酸途徑和鄰苯二甲酸途徑。高效液相色譜定量分析結果表明,菌株對菲的降解以水楊酸途徑為主,且該途徑通過鄰苯二酚-2,3-雙加氧酶使苯環(huán)發(fā)生間位斷裂,生成2-羥基黏糠酸半醛。(5)菌株在降解菲的過程中會產(chǎn)生黃色色素,且隨著菲降解率的增大而色度加深,根據(jù)GC-MS、傅里葉紅外及紫外可見光譜分析,可推測為類胡蘿卜素中的β-胡蘿卜素。
[Abstract]:Phenanthrene (phenanthrene) is a polycyclic aromatic hydrocarbon (PAHs),) with three benzene rings, which has stable chemical properties and strong hydrophobicity. It can persist in soil, water and air contaminated by fossil materials such as coal, petroleum and so on. And through the food chain to enrich the human body so that human cells produce cancer. At present, microbial remediation of polycyclic aromatic hydrocarbons (PAHs) pollution in the environment has received extensive attention, especially the screening of high efficient PAHs degradation bacteria has become a hot topic. Therefore, a phenanthrene biodegradable strain was obtained from reflux sludge of coking wastewater treatment plant by domestication. The strain was identified by morphological observation, physiological and biochemical characteristics and 16s rDNA sequencing. The growth conditions of phenanthrene were optimized by response surface method, and the degradation characteristics and pathways of phenanthrene were investigated by means of GC-MS, high performance liquid chromatography and Fourier transform infrared spectroscopy. The results are as follows: (1) A highly efficient biodegradable bacterium, named P-1, was isolated from the reflux sludge of coking wastewater treatment plant and could grow with phenanthrene as the sole carbon source and energy source. Morphological observation showed that the strain was Gram-positive, the colony was yellowish, round, brim neat, hemispherical high convex, smooth and moist surface. The bacteria were small and arranged in the shape of a short rod. The size of the bacteria was about 0.2 脳 0. 5 0. 8 渭 m.16S rDNA. The results showed that the strain P-1 might be sphingomonas. (2) by single factor experiment, Plackett-Burman test, the strain P-1 might belong to sphingomonas. The optimum growth conditions of the strain were optimized by the steepest climbing test and response surface test. The temperature was 33 鈩，

本文編號：2390211