多環(huán)芳烴菲降解工程菌的研發(fā)及應(yīng)用
發(fā)布時(shí)間：2018-12-07 15:46
【摘要】：多環(huán)芳烴(polycyclic aromatic hydrocarbon,PAHs)是一種存在范圍十分廣泛的有毒物質(zhì),通常會(huì)在不同介質(zhì)中持續(xù)的積累。菲(Phenanthrene)作為一種特殊的含三個(gè)苯環(huán)的芳烴,具有典型的致癌性區(qū)域“灣”區(qū)(Bayregion)和“K”區(qū)(Kregion)。菲憑借其本身特殊的化學(xué)組成,現(xiàn)已成為許多科學(xué)家探究PAHs致癌性的代表物質(zhì)。利用微生物的代謝與分解可以促使環(huán)境中的一些有毒害物質(zhì)進(jìn)行自然衰減。由于生物處理技術(shù)是一種需求運(yùn)行資金少、處理效率高、無(wú)二次環(huán)境污染及具備其它諸多特點(diǎn)的環(huán)保技術(shù),因此利用該手段治理菲污染是最具競(jìng)爭(zhēng)力的有效途徑之一。目前,針對(duì)底物濃度較高的情況利用微生物進(jìn)行降解的報(bào)道并不常見(jiàn),但是由于一些特殊的人為活動(dòng),如工業(yè)、礦業(yè)、農(nóng)業(yè)等,并且土壤本身環(huán)境背景值較高等其它因素,導(dǎo)致多環(huán)芳烴的污染程度嚴(yán)重。因此,獲得性能良好的菲降解菌株具有一定的應(yīng)用價(jià)值。從沈陽(yáng)北部污水處理廠取得的活性污泥中分離、篩選得到利用菲作為碳源進(jìn)行代謝,且具有良好降解能力的菌株20株。分別進(jìn)行20株菌株降解菲的試驗(yàn),發(fā)現(xiàn)其中6株菌株具有良好的降解菲的能力,分別為W2、W6、W9、W12、W16和W20,菲降解率都在50%以上。對(duì)6株優(yōu)良菌株進(jìn)行復(fù)篩,其中菌株W12的降解效果與生長(zhǎng)性能均處于最佳狀態(tài),確定菌株W12為高效菲降解菌株。通過(guò)對(duì)菌株W12進(jìn)行基本的形態(tài)特征、生理生化特性、16S rDNA測(cè)序分析,鑒定菌株W12為耳炎假單胞菌(Pseudomonas otitidis.)。耳炎假單胞菌屬于新型菌株,目前關(guān)于該菌株降解菲的相關(guān)報(bào)道很少見(jiàn)。同時(shí)報(bào)道了該菌株的基因組序列,為這類菌株提供了可參考的基因組。菌株W12的降解特性試驗(yàn)表明,菌株降解菲的最佳溫度為30℃,最佳pH值為7.0左右,最適接種量為10%;當(dāng)鹽度為2%時(shí),菲降解率及菌株的生長(zhǎng)均表現(xiàn)出明顯的下降趨勢(shì),其最適鹽度為0.5%;加入蛋白胨和酵母膏促進(jìn)了菌株對(duì)菲的降解,使降解率分別提高到75.65%和70.85%,而葡萄糖的加入則抑制了菌株對(duì)菲的降解;在不同無(wú)機(jī)氮源下,菌株的生長(zhǎng)狀況及對(duì)菲的降解變化波動(dòng)不大,以磷酸氫二銨作為氮源時(shí),生長(zhǎng)及降解菲情況最佳,其次是硫酸銨,硝酸鈉的影響則不是很明顯;當(dāng)每個(gè)環(huán)境因子都處于最適宜范圍時(shí),菲濃度為1000mg/L的樣品,經(jīng)菌株進(jìn)行96小時(shí)的降解,降解率達(dá)65.80%,對(duì)菲的耐受濃度可達(dá)2000mg/L。當(dāng)菲濃度為500mg/L時(shí),菲降解率和降解速率均較高,菌株對(duì)菲的降解動(dòng)力學(xué)遵循Monod方程模型,菌株的模型參數(shù)為:vm=0.7710,ks=170.3315,mm=0.0540;菲濃度為1000mg/L時(shí),其降解過(guò)程基本符合Haldane方程,菌株的動(dòng)力學(xué)參數(shù)為:vm=2.66,ks=603.25,ki=1059.06,mm=0.0400。
[Abstract]:Polycyclic aromatic hydrocarbons (polycyclic aromatic hydrocarbon,PAHs) is a widespread toxic substance, which usually accumulates in different media. Phenanthrene (Phenanthrene), as a special aromatic hydrocarbon with three benzene rings, has typical carcinogenic regions, (Bayregion) and (Kregion). In "bay" and "K" regions. Because of its special chemical composition, phenanthrene has become a representative of many scientists to explore the carcinogenicity of PAHs. The metabolism and decomposition of microorganisms can promote the natural attenuation of some toxic substances in the environment. Because biological treatment technology is a kind of environmental protection technology with less running capital, high treatment efficiency, no secondary environmental pollution and many other characteristics, it is one of the most effective ways to use this method to control phenanthrene pollution. At present, it is not common to report the use of microorganisms for degradation of high substrate concentrations, but due to some special human activities, such as industry, mining, agriculture, and other factors, such as higher environmental background value of the soil itself, The pollution of polycyclic aromatic hydrocarbons (PAHs) is serious. Therefore, it has certain application value to obtain phenanthrene degrading strains with good performance. Twenty strains of phenanthrene were isolated from activated sludge obtained from wastewater treatment plant in northern Shenyang and were metabolized by phenanthrene as carbon source. 20 strains of phenanthrene were tested, and 6 strains were found to have a good ability to degrade phenanthrene. The results showed that the degradation rate of phenanthrene was more than 50%. Six excellent strains were screened, among which, the degradation effect and growth performance of strain W12 were in the best condition, and the strain W12 was determined to be a high-efficient phenanthrene degrading strain. The strain W12 was identified as Pseudomonas auricularis (Pseudomonas otitidis.). By basic morphological, physiological and biochemical characteristics and 16s rDNA sequencing. Pseudomonas auricularis is a new strain, and there are few reports about it degrading phenanthrene. At the same time, the genomic sequence of this strain is reported, which provides the reference genome for this kind of strain. The degradation characteristics of strain W12 showed that the optimum temperature, pH and inoculation amount of phenanthrene were 30 鈩，
本文編號(hào)：2367421
[Abstract]:Polycyclic aromatic hydrocarbons (polycyclic aromatic hydrocarbon,PAHs) is a widespread toxic substance, which usually accumulates in different media. Phenanthrene (Phenanthrene), as a special aromatic hydrocarbon with three benzene rings, has typical carcinogenic regions, (Bayregion) and (Kregion). In "bay" and "K" regions. Because of its special chemical composition, phenanthrene has become a representative of many scientists to explore the carcinogenicity of PAHs. The metabolism and decomposition of microorganisms can promote the natural attenuation of some toxic substances in the environment. Because biological treatment technology is a kind of environmental protection technology with less running capital, high treatment efficiency, no secondary environmental pollution and many other characteristics, it is one of the most effective ways to use this method to control phenanthrene pollution. At present, it is not common to report the use of microorganisms for degradation of high substrate concentrations, but due to some special human activities, such as industry, mining, agriculture, and other factors, such as higher environmental background value of the soil itself, The pollution of polycyclic aromatic hydrocarbons (PAHs) is serious. Therefore, it has certain application value to obtain phenanthrene degrading strains with good performance. Twenty strains of phenanthrene were isolated from activated sludge obtained from wastewater treatment plant in northern Shenyang and were metabolized by phenanthrene as carbon source. 20 strains of phenanthrene were tested, and 6 strains were found to have a good ability to degrade phenanthrene. The results showed that the degradation rate of phenanthrene was more than 50%. Six excellent strains were screened, among which, the degradation effect and growth performance of strain W12 were in the best condition, and the strain W12 was determined to be a high-efficient phenanthrene degrading strain. The strain W12 was identified as Pseudomonas auricularis (Pseudomonas otitidis.). By basic morphological, physiological and biochemical characteristics and 16s rDNA sequencing. Pseudomonas auricularis is a new strain, and there are few reports about it degrading phenanthrene. At the same time, the genomic sequence of this strain is reported, which provides the reference genome for this kind of strain. The degradation characteristics of strain W12 showed that the optimum temperature, pH and inoculation amount of phenanthrene were 30 鈩，
本文編號(hào)：2367421
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