本文關(guān)鍵詞： 蒼白桿菌PW 共代謝 Tween80 TPPB 代謝途徑　出處：《北京化工大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

【摘要】：多環(huán)芳烴(Polycyclic Aromatic Hydrocarbons, PAHs)是一類廣泛存在于土壤、水環(huán)境等自然環(huán)境中的有機污染物,其主要是由煤、石油、天然氣等含碳化合物不完全燃燒產(chǎn)生的。由于多環(huán)芳烴具有“三致”的危害效應(yīng)、化學(xué)結(jié)構(gòu)穩(wěn)定而難以被降解以及脂溶性高而易通過食物鏈進入人體積累等特點易于對生態(tài)環(huán)境產(chǎn)生危害,并對人體健康產(chǎn)生潛在的威脅,因此,對于多環(huán)芳烴污染修復(fù)的研究亟待進行。本文以芘(Pyrene)為研究對象,以本實驗室從北京焦化廠多環(huán)芳烴污染土壤篩選得到的一株芘的高效降解菌蒼白桿菌PW(Ochrobactrum sp. PW)為菌株,研究了共代謝對蒼白桿菌PW降解芘的影響,并對無機鹽液體培養(yǎng)基(MSM)的部分成分作了單因子試驗,探討了表面活性劑以及兩相分配生物反應(yīng)器(TPPB)應(yīng)用于多環(huán)芳烴微生物修復(fù)的可行性,并初步分析了蒼白桿菌PW降解芘的下游途徑,主要研究結(jié)果如下：(1)選取胰蛋白胨、酵母浸粉、麥芽糖和醋酸鈉分別作為外加碳源,其中酵母浸粉對促進蒼白桿菌PW降解芘的效果最顯著。以酵母浸粉作為外加碳源,其濃度為50 mg/L時能夠促進芘的降解,但當其濃度超過100mg/L時,反而會抑制芘的降解；將MSM培養(yǎng)基中的FeSO4濃度由1 mg/L變?yōu)? mg/L,能夠促進芘的降解,而改變(NH4)2SO4和K2HPO4的則會抑制芘的降解。(2) Tween80能夠顯著增加芘在水中的溶解度,且芘的溶解度隨著Tween80的濃度提高而增加；Tween80能夠提高蒼白桿菌PW對芘的利用效率,促進芘的降解,如Tween80濃度分別為100 mg/L和250 mg/L,芘的濃度為100 mg/L時,芘在第5-8 d的降解率分別為80.3%-91.1%和88.6%-93.5%,高于對照組的73.3%-92.5%。但當Tween80濃度過高時,其反而會抑制芘的降解,且芘濃度越高,Tween80對芘的降解的促進效果越差。(3) TPPB技術(shù)對蒼白桿菌PW降解芘具有一定的促進作用。TPPB技術(shù)對芘降解的影響受到有機相的種類、有機相的比例、芘濃度以及液體擾動速率等因素的影響。液體擾動速率的增加,能夠增加水相與有機相之間的接觸面積以及芘在兩相之間的傳質(zhì)速率,從而促進芘的降解；對于同一種有機相,在芘的濃度較高時,適當提高有機相的比例能夠促進芘的降解,如芘的初始濃度為1000 mg/L,有機相比例為2.5%-20%時,水-十六烷體系中芘的降解率分別為24.3%-44.3%,水-十八烷體系中芘的降解率分別為22.6%-48.8%,反之,當芘的濃度較低時,應(yīng)降低有機相的比例。(4)蒼白桿菌PW降解芘的下游途徑有兩條,一條為鄰苯二甲酸途徑,另外一條為水楊酸途徑,在水楊酸途徑中,水楊酸并未被降解為鄰苯二酚,而是通過其它途徑進入三羧酸循環(huán)。
[Abstract]:Polycyclic Aromatic hydrocarbons (PAHs) are a class of organic pollutants in the natural environment, such as soil, water environment and so on. Because polycyclic aromatic hydrocarbons (PAHs) have a "triple-induced" hazard effect, The chemical structure is stable and difficult to degrade, and the characteristics of high liposolubility and easy accumulation through the food chain are easy to harm the ecological environment and pose a potential threat to human health. It is urgent to study the remediation of polycyclic aromatic hydrocarbons (PAHs) pollution. In this paper, Pyrene Pyrene was used as the research object, and a pyrene degrading bacterium, PW(Ochrobactrum sp. PWS, was selected from PAHs contaminated soil of Beijing Coking Plant in our laboratory. The effect of co-metabolism on PW degradation of pyrene by Bacillus pallidus was studied. The feasibility of the application of surfactant and TPPBin in microbial remediation of polycyclic aromatic hydrocarbons (PAHs) was discussed. The downstream pathway of PW degradation of pyrene by P. pallidus was preliminarily analyzed. The main results were as follows: 1) tryptone was selected. Yeast extract powder, maltose and sodium acetate were respectively used as additional carbon sources, among which yeast extract powder had the most significant effect on promoting PW degradation of pyrene. Yeast extract powder could promote pyrene degradation when the concentration of yeast extract powder was 50 mg/L. But when the concentration was over 100mg / L, the degradation of pyrene was inhibited, and the concentration of FeSO4 in MSM medium was changed from 1 mg/L to 2 mg / L, which could promote the degradation of pyrene. However, changing NH _ 4H _ 2SO _ 4 and K _ 2HPO _ 4 could inhibit the degradation of pyrene. Tween80 could significantly increase the solubility of pyrene in water, and the solubility of pyrene increased with the increase of Tween80 concentration. Tween80 could increase the utilization efficiency of pyrene and promote the degradation of pyrene by PW. If the concentration of Tween80 was 100 mg/L and 250 mg / L, and the concentration of pyrene was 100 mg/L, the degradation rates of pyrene were 80.3% -91.1% and 88.6-93.5% at 5-8 days, respectively, which were higher than those of the control group (73.3 -92.5%). However, when the concentration of Tween80 was too high, the degradation of pyrene was inhibited. The higher the concentration of pyrene is, the worse the effect of Tween80 on the degradation of pyrene is. The TPPB technique can promote the degradation of pyrene by PW. The effect of Tween80 on the degradation of pyrene is affected by the kinds of organic phase and the proportion of organic phase. The increase of liquid disturbance rate can increase the contact area between water phase and organic phase and the mass transfer rate of pyrene between two phases, thus promoting the degradation of pyrene. When the concentration of pyrene is high, increasing the proportion of organic phase can promote the degradation of pyrene, such as when the initial concentration of pyrene is 1000 mg / L, the proportion of organic phase is 2.5-20%, The degradation rates of pyrene in water-cetane system were 24.3-44.3 and 22.6-48.8 in water-cetane system, respectively. On the contrary, when the concentration of pyrene was low, the proportion of organic phase should be reduced. One is the phthalic acid pathway, the other is the salicylic acid pathway. In the salicylic acid pathway, salicylic acid is not degraded to catechol, but enters the tricarboxylic acid cycle through other channels.
【學(xué)位授予單位】：北京化工大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：X172;X592

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本文編號：1549612