多环芳烃降解菌的筛

发布时间：2018-02-04 07:31

本文关键词： 多环芳烃降解特性高效降解菌系植物-微生物协同修复　出处：《东北农业大学》2015年硕士论文　论文类型：学位论文

【摘要】：多环芳烃(Polycyclic aromatic hydrocarbons,PAHs)是一类在环境中广泛存在、具有高毒性、高生物富集性、持久性和难降解等特点的有机污染物。多环芳烃可持久性的存在于土壤中,其具有不可逆、易迁移却不易降解等特性,危害性大且不易治理,多环芳烃污染土壤的治理问题,越来越受到全世界的关注。目前修复环芳烃污染土壤的主要技术包括物理修复、化学修复、微生物修复、植物修复、以及微生物与植物联合修复。其中植物修复与微生物技术还停留在实验室阶段,不能大规模应用于实践修复与商业领域。这可能由于菌株或植物本身很难适应自然污染环境导致的。将高效降解菌与植物联合修复多环芳烃污染土壤,能够有效的增强修复效果,具有较好的应用前景。本研究从中国农业微生物菌种中心选取菌种,通过平板升华法进行筛选,得到4株直径大于10mm的多环芳烃降解菌,分别为02173、02830、SL-1、F11。02173与02830被鉴定为Pseudomonas mendocina,Pseudomonas plecoglossicida,SL-1和F11为Rhizobium petrolearium。将筛选到的菌株SL-1、02173、02830、F11进行液体摇瓶培养,研究其降解性能。在TSB液体培养基中添加浓度为100ppm的混合多环芳烃,发现菌株在其内培养5天有较好的降解效果,对芴的降解率分别为37.31%,55.96%,51.53%和74.61%,对菲的降解率分别为36.86%,48.26%,49.79%和71.91%。对蒽的降解率分别为6.68%,9.98%,13.89%和7.42%,对芘的降解率分别为14.06%,7.92%,13.89%和10.35%。为了研究微生物与植物联合修复多环芳烃污染土壤的功效,本实验采用盆栽试验,研究苜蓿与不同微生物联合对污染土壤中多环芳烃的修复效果。将筛选得到的三株降解菌02173、02830、SL-1有机组合成5个处理,02173、02830、SL-1、P(02173+02830)和P+S(02173+02830+SL-1),再分别与苜蓿联合修复污染土壤。20天后发现植株生长均较为缓慢,矮小,不同处理间没有明显差异。60天后,苜蓿生长茂盛,接入菌剂处理的植株干重与株高都要略高于没有接入菌剂的处理,其中P+S+Ms处理的干重与株高值最大,分别为0.0224g和13.5cm,说明在高浓度多环芳烃污染土壤中,该降解菌株对苜蓿的生长有一定的促进作用。苜蓿与降解菌株联合修复土壤中低环多环芳烃的降解率在25.69%~45.61%之间。微生物与植物联合修复的PAHs去除率都要高于只接种菌剂和只种植植物的处理。SL-1+Ms、P+S+Ms的处理,是所有处理中去除效果最好的两组。
[Abstract]:Polycyclic aromatic hydrocarbonization (PAHs) is a class of polycyclic aromatic hydrocarbons (PAHs), which is widely found in the environment and has high toxicity and bioconcentration. Persistent and refractory organic pollutants. Polycyclic aromatic hydrocarbons (PAHs) are persistent in soil. They are irreversible, easy to migrate but difficult to degrade, and are harmful and difficult to treat. The treatment of polycyclic aromatic hydrocarbons (PAHs) contaminated soil has attracted more and more attention all over the world. At present, the main technologies for remediation of soils contaminated by PAHs include physical remediation, chemical remediation, microbial remediation and phytoremediation. Among them, phytoremediation and microbial technology are still in the laboratory stage. This may be due to the fact that it is difficult for strains or plants to adapt to the natural pollution environment. Highly efficient biodegradable bacteria are combined with plants to repair polycyclic aromatic hydrocarbons (PAHs) contaminated soils. This study can effectively enhance the repair effect and has a good application prospect. This study selected strains from the center of agricultural microorganism in China and screened them by plate sublimation method. Four strains of polycyclic aromatic hydrocarbons (PAHs) degrading bacteria with diameter of more than 10mm were obtained, which were 02173 and 02830 SL-1, respectively. F11.02173 and 02830 were identified as Pseudomonas mendocina Pseudomonas plecoglossicida. SL-1 and F11 were Rhizobium Petrolearium.The strains SL-1, 02173, 02830 and F11 were used for liquid flask culture. The degradation performance was studied. Adding 100ppm mixed polycyclic aromatic hydrocarbons (PAHs) into the TSB liquid medium, it was found that the strain cultured in the medium for 5 days had a good degradation effect. The degradation rates of fluorene were 37.31% and 74.61%, respectively, and the degradation rates of phenanthrene were 36.86% and 48.26%, respectively. The degradation rate of anthracene was 6.68% and 7.42%, respectively, and the degradation rate of pyrene was 14.06% and 7.92%, respectively. In order to study the effect of microorganism and plant on remediation of soil contaminated by polycyclic aromatic hydrocarbons (PAHs), pot experiment was used in this experiment. The remediation effect of alfalfa combined with different microorganisms on polycyclic aromatic hydrocarbons (PAHs) in contaminated soil was studied. SL-1 (02173 02830) and PS-02173 (02830 SL-1). After 20 days of remediation of contaminated soil with alfalfa, it was found that the growth of alfalfa was relatively slow and short, and there was no obvious difference between different treatments. 60 days later, the growth of alfalfa was prosperous. The dry weight and height of plants treated with inoculation agent were slightly higher than those without inoculation agent, and the dry weight and plant height of PS Ms treatment were 0.0224g and 13.5cm, respectively. It shows that high concentration of polycyclic aromatic hydrocarbons (PAHs) pollutes soil. The degradation rate of low cyclic polycyclic aromatic hydrocarbons (PAHs) in soil repaired by alfalfa and biodegradable strains was between 25.69% and 45.61%. The removal rate of PAHs in compound plants was higher than that in inoculated and plant-only treatments. SL-1. Ms. P S Ms treatment was the best two groups of all treatments.
【学位授予单位】：东北农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X17;X53

【参考文献】