Mycobacterium sp. WY10的特性及其对菲和芘的降解研究

发布时间：2018-06-24 02:17

  本文选题：菲 + 芘　； 参考：《浙江大学》2017年硕士论文

【摘要】：多环芳烃(Polycyclic Aromatic Hydrocarbons,PAHs)是一种环境中广泛分布的有机污染物,具有致畸、致癌和致突变等毒性,严重危害着人类健康以及生态环境。如何去除环境中的PAHs引起了全世界的广泛研究,许多研究表明微生物修复是高效去除环境中PAHs的主要手段之一。因此,获得PAHs高效降解菌以及生物修复过程中降解菌的修复效果等对实际环境中的PAHs污染的微生物治理具有非常重要的指导意义。本研究从PAHs污染的土壤中筛选分离获得了一株高效降解菌WY10,并对这株菌进行了鉴定;同时探究了菌株WY10降解菲和芘的影响因素,以及菌株WY10在菲和芘污染土壤修复中的应用和修复过程中PAHs降解基因的丰度变化,得到了以下主要研究结果:(1)通过形态学、生理生化以及16SrRNA、hsp65、recA和r叩oB基因的序列分析等手段进行鉴定,判定菌株WY10属于分枝杆菌属(Mycobacterium)。(2)菌株WY10可以分别在pH(4.5-8.5)和温度(20-35 ℃)的范围内高效地降解菲和芘。菲和芘的最佳降解条件分别是:pH 4.5-7.5、温度30-35 ℃和pH 4.5-7.5、温度28-35℃。在pH6.5、温度28℃条件下培养72h,菲(100mg·L-1)和芘(50 mg·L-1)的降解率分别高达100.0%和92.3%。除了培养24h之前葡萄糖和麦芽糖的添加会促进菌株WY10对芘的降解外,果糖、葡萄糖和麦芽糖添加浓度为100mgL-1时,对菌株WY10降解菲和芘都没有显著的影响。(3)菌株WY10对土壤中的菲和芘也有非常高的降解效果,接种WY10的土壤培养35天后,菲和芘的浓度分别从39.8 mg·kg-1和18.2 mg·kg-1快速降解到后3.0mg·kg-1和1.1mg·kg-1;土壤中的土著微生物也能降解土壤中的菲和芘,降解后期对照处理土壤中菲和芘的残留浓度分别为5.0 mg·kg-1和2.9 mg·kg-1。(4)土壤中Mycobacterium 16S rRNA、RHDα-GP、nidA、nidB基因丰度都随着菲和芘的降解而逐渐增加,同时土壤中菲和芘的残留浓度与Mycobacterium 16S rRNA、RHDα-GP、nid4、nidB基因丰度呈现非常高的负相关性,说明土壤中分枝杆菌以及携带有RHDα-GP、nidA和nindB基因的微生物对土壤中菲和芘的降解起到非常重要的作用。
[Abstract]:Polycyclic Aromatic hydrocarbons (PAHs) are widely distributed organic pollutants in the environment, with teratogenic, carcinogenic and mutagenic toxicity, which seriously harm human health and ecological environment. How to remove PAHs from the environment has caused extensive research all over the world. Many studies have shown that microbial remediation is one of the main methods to efficiently remove PAHs from the environment. Therefore, it is very important to obtain the efficient degradation bacteria of PAHs and the remediation effect of biodegradable bacteria in the process of bioremediation for the treatment of PAHs pollution in the actual environment. In this study, a strain WY10 was isolated from PAHs contaminated soil and identified, and the factors influencing the degradation of phenanthrene and pyrene by strain WY10 were investigated. The application of strain WY10 in phytoremediation of phenanthrene and pyrene contaminated soil and the changes in the abundance of PAHs degradation genes during remediation were obtained. The main results were as follows: (1) Morphology, Physiological and biochemical methods and sequence analysis of 16s rRNA hsp65recA and r koroB genes were used to identify the strain WY10, which belongs to Mycobacterium). (2 strain, which can efficiently degrade phenanthrene and pyrene in the range of pH (4.5-8.5) and temperature (20-35 鈩，

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