多环芳烃菲降解工程菌的研发及应用
发布时间：2018-12-07 15:46
【摘要】：多环芳烃(polycyclic aromatic hydrocarbon,PAHs)是一种存在范围十分广泛的有毒物质,通常会在不同介质中持续的积累。菲(Phenanthrene)作为一种特殊的含三个苯环的芳烃,具有典型的致癌性区域“湾”区(Bayregion)和“K”区(Kregion)。菲凭借其本身特殊的化学组成,现已成为许多科学家探究PAHs致癌性的代表物质。利用微生物的代谢与分解可以促使环境中的一些有毒害物质进行自然衰减。由于生物处理技术是一种需求运行资金少、处理效率高、无二次环境污染及具备其它诸多特点的环保技术,因此利用该手段治理菲污染是最具竞争力的有效途径之一。目前,针对底物浓度较高的情况利用微生物进行降解的报道并不常见,但是由于一些特殊的人为活动,如工业、矿业、农业等,并且土壤本身环境背景值较高等其它因素,导致多环芳烃的污染程度严重。因此,获得性能良好的菲降解菌株具有一定的应用价值。从沈阳北部污水处理厂取得的活性污泥中分离、筛选得到利用菲作为碳源进行代谢,且具有良好降解能力的菌株20株。分别进行20株菌株降解菲的试验,发现其中6株菌株具有良好的降解菲的能力,分别为W2、W6、W9、W12、W16和W20,菲降解率都在50%以上。对6株优良菌株进行复筛,其中菌株W12的降解效果与生长性能均处于最佳状态,确定菌株W12为高效菲降解菌株。通过对菌株W12进行基本的形态特征、生理生化特性、16S rDNA测序分析,鉴定菌株W12为耳炎假单胞菌(Pseudomonas otitidis.)。耳炎假单胞菌属于新型菌株,目前关于该菌株降解菲的相关报道很少见。同时报道了该菌株的基因组序列,为这类菌株提供了可参考的基因组。菌株W12的降解特性试验表明,菌株降解菲的最佳温度为30℃,最佳pH值为7.0左右,最适接种量为10%;当盐度为2%时,菲降解率及菌株的生长均表现出明显的下降趋势,其最适盐度为0.5%;加入蛋白胨和酵母膏促进了菌株对菲的降解,使降解率分别提高到75.65%和70.85%,而葡萄糖的加入则抑制了菌株对菲的降解;在不同无机氮源下,菌株的生长状况及对菲的降解变化波动不大,以磷酸氢二铵作为氮源时,生长及降解菲情况最佳,其次是硫酸铵,硝酸钠的影响则不是很明显;当每个环境因子都处于最适宜范围时,菲浓度为1000mg/L的样品,经菌株进行96小时的降解,降解率达65.80%,对菲的耐受浓度可达2000mg/L。当菲浓度为500mg/L时,菲降解率和降解速率均较高,菌株对菲的降解动力学遵循Monod方程模型,菌株的模型参数为:vm=0.7710,ks=170.3315,mm=0.0540;菲浓度为1000mg/L时,其降解过程基本符合Haldane方程,菌株的动力学参数为: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，
本文编号：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，
本文编号：2367421
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