分散剂及生物柴油对石油降解微生物多样性的影响研究

发布时间：2018-04-14 18:56

本文选题：石油污染 + 生物修复　；参考：《青岛理工大学》2014年硕士论文

【摘要】：石油是当今社会生产发展的重要能源。随着人类社会的快速进步与发展，石油需求量大大增加，这就导致每年都有大量的石油由于突发事件进入海洋等水域，造成极其严重的后果，对海洋生态平衡构成了严重破坏与威胁。在石油发生泄漏后，往往在第一时间向海洋中投加分散剂，尽可能的降低石油污染对海洋的影响，并且在后续生物修复过程中会投加生物柴油促进石油的生物降解，分散剂和生物柴油的投加都可能会对石油降解微生物造成影响。目前，对分散剂以及生物柴油处理后的石油污染海水中微生物种群多样性的变化尚未开展系统的研究。因此，本课题将基于分子生物学的克隆文库技术和PCR-RFLP技术相结合的方法，研究并分析分散剂以及生物柴油的投加对石油污染海水中微生物群落结构多样性的影响，并在研究中得到以下结论：（1）随着分散剂投加量的增加，石油污染海水中的优势菌群逐渐从食碱菌科Alcanivorax、海洋螺菌科Marinomonas、黄杆菌科Flavobacterium以及产碱菌科Achromobacter向红菌科Parvibaculum、红螺菌科Thalassospira过渡。（2）随着生物柴油投加量的增大，其污染海水中的优势菌群逐渐由食碱菌科Alcanivorax、红菌科Parvibaculum和海洋螺菌科Marinomonas变为红螺菌科Thalassospira，鞘脂单胞菌科Novosphingobium。（3）生物柴油的投加与分散剂相比更能促进海水中微生物的生长，提高生物降解效率。分散剂以及生物柴油在相同的投加量下，投加生物柴油的污染海水中微生物的含量明显高于投加分散剂的污染海水且石油降解率也是投加生物柴油的海水中较高。（4）克隆子测序结果通过NCBI比对后显示，16S rDNA克隆文库中均只有50%-70%的克隆子测序结果可以在NCBI中找到相似度大于97%的菌株。因此表明，在各个条件下海水中石油降解微生物中均存在部分未被人类分类培养和鉴定的细菌种类。（5）石油污染海水中，，海水细菌主要由变形菌纲以及黄杆菌纲和放线菌纲的细菌组成，其中α-变形菌纲以及γ-变形菌纲占绝对优势，分散剂的投加有利于γ-变形菌纲以及黄杆菌纲微生物的生长与繁殖，而生物柴油的投加更有利于α-变形菌纲微生物的生长繁殖。（6）生物柴油以及分散剂的投加能促进芳香烃降解菌大量繁殖，并逐步成为优势菌群，且随着分散剂以及生物柴油投加量的增加，污染海水中芳香烃降解菌的比重也逐步增大，这表明生物柴油以及分散剂的投加能促进石油中芳香烃类物质的降解。
[Abstract]:Petroleum is an important energy source for the production and development of our society.With the rapid progress and development of human society, the demand for oil has increased greatly. This has led to a large amount of oil entering the sea and other waters every year due to unexpected events, resulting in extremely serious consequences.It is a serious damage and threat to the marine ecological balance.After oil spills, dispersants are often added to the ocean for the first time to minimize the impact of oil pollution on the ocean, and biodiesel is added to the subsequent bioremediation process to promote the biodegradation of oil.The addition of dispersants and biodiesel may have an impact on petroleum degradation microbes.At present, no systematic study has been carried out on the variation of microbial population diversity in seawater contaminated by petroleum and biodiesel treated with dispersants and biodiesel.Therefore, based on the methods of molecular biology and PCR-RFLP, the effects of dispersant and biodiesel on the diversity of microbial community in petroleum polluted seawater were studied and analyzed.The conclusions are as follows:1) with the increase of dispersant dosage, the dominant flora of petroleum polluted seawater gradually transitioned from Alcanivorax, Marinomonas, Flavobacterium and Achromobacter to Parvibaculum and Thalassospira.2) with the increase of biodiesel dosage, the dominant flora in polluted seawater changed from Alcanivorax, Parvibaculum and Marinomonas to Thalassospira and Novosphingobium.3) compared with dispersant, the addition of biodiesel can promote the growth of microorganisms in seawater and improve the biodegradation efficiency.Under the same dosage of dispersant and biodiesel, the microbial content of polluted seawater added with biodiesel was significantly higher than that of polluted seawater with dispersant, and the oil degradation rate was also higher in the seawater fed with biodiesel.The results of clone sequencing showed that only 50% -70% clones of 16s rDNA clones could be found in NCBI with a similarity of more than 97%.It is concluded that there are some species of petroleum degrading microorganisms in seawater which have not been cultured and identified by human taxonomy.In petroleum polluted seawater, seawater bacteria are mainly composed of Proteus, xanthobacterium and actinomycetes, among which 伪 -Proteus and 纬 -Proteus are dominant.The addition of dispersant is beneficial to the growth and reproduction of 纬 -Proteus and Xanthobacterium, while the addition of biodiesel is more favorable to the growth and reproduction of 伪 -Proteus.(6) the addition of biodiesel and dispersant can promote the proliferation of aromatic hydrocarbon degrading bacteria and gradually become the dominant flora, and with the increase of dispersant and biodiesel dosage, the proportion of aromatic hydrocarbon degrading bacteria in polluted sea water increases gradually.This indicates that the addition of biodiesel and dispersant can promote the degradation of aromatic hydrocarbons in petroleum.
【学位授予单位】：青岛理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：X172;X55

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