冻融作用下湿地土壤微生物对石油污染的响应特征研究

With the sharp increasing population and modernization of society, environment pollution and global warming are aggravating. As one of the most important members of the ecosystem, soil microorganism is extremely sensitive to the change of environmental conditions and is regarded as the ultimate frontier of soil science by "Science". Recently, petroleum pollution status in wetlands soils in northeast China is becoming increasingly serious, which poses a severe threat to the sustainable development and utilization of wetland resources. To achieve the restoration of polluted environment, it is necessary to clarify the internal relation between oil pollution and wetland soil under the guidance of local conditions. Therefore, this project aims to explore the response property of microorganism in wetland soil on petroleum pollution under freeze-thaw condition (a case of the petroleum polluted soils in Momoge wetland, Jilin Province). In this project, a series of experiments with field monitoring and indoor simulation will be carried out. Varied traditional and modern microbiological technology and the advanced test methods will be applied to comprehensively analyze the interaction between petroleum hydrocarbons and microorganisms in wetland soil under the action of freezing and thawing at the microbial community, individual strains and molecular level, respectively. The expected results of this project will provide theoretical basis for the development of microbial remediation technology with regional characteristics, which is of great practical significance.

随着人口的急剧增多和社会的现代化，环境污染与全球变暖的趋势不断加重。土壤微生物作为生态系统中最重要的成员之一，对这种环境条件的变化反应极为敏感，被《Science》视为土壤科学的最终前沿。目前，东北地区的湿地型油田在开采过程中造成的土壤石油污染问题日益严峻，对湿地资源的可持续发展与利用造成严重威胁。如需在不过渡干扰环境的前提下，实现污染环境的修复，就必须在因地制宜的指导思想下，明确石油污染与湿地土壤之间的内在联系。因此，本项目以吉林省莫莫格湿地石油污染区土壤为研究对象，旨在探索冻融作用下湿地土壤微生物对石油污染胁迫的响应特征。通过野外监测和室内模拟实验，利用传统和现代的微生物学检测技术，结合先进的分析测试手段，从群落、个体菌株和分子水平上全面解析冻融作用下石油烃与湿地土壤微生物间的互作规律。本项目的预期成果将为发展具有地域特色的微生物修复技术提供理论依据，具有重要的现实意义。

本项目以湿地石油污染区土壤为研究对象，通过野外监测和室内模拟实验，利用传统和现代的微生物学检测技术，重点探讨了石油烃降解菌对石油污染胁迫的响应特征。项目组从湿地石油污染区土壤中分离筛选到两株耐盐石油烃降解菌，经分类鉴定分别命名为Delftia sp. FM6-1和Achromobacter sp. FM8-1。研究表明，这两株菌对盐浓度具有较广的适应范围，菌株FM8-1的最佳生长盐浓度为4% (m/v)，菌株FM6-1的生长在盐浓度为2.5%以内不受影响。此外，这两株菌均可利用芳香烃(萘、菲、荧蒽和芘)和脂肪烃(C12、C16、C20和C32)作为唯一碳源来进行生长。通过底物适应性阈值的研究发现，菌株FM8-1对石油烃组分的耐受程度高于菌株FM6-1。为进一步解析这两株菌对石油烃的降解性能，以菲作为底物，详细探讨了这两株菌对菲的降解动力学特征，并分别从个体菌株、代谢和细胞水平解析了这两株菌对菲的降解途径和降解性能。其中菌株FM6-1通过“邻苯二甲酸”途径代谢菲，菌株FM8-1则通过“萘”途径代谢菲。该研究成果以第一作者兼通讯作者发表于Science of the Total Environment。从莫莫格湿地的石油污染土壤中，以菲( Phe)作为唯一碳源，分离出一株多环芳烃耐盐碱的Phe高效降解细菌株 S1-8，经鉴定属于盐单胞菌，命名为Halomonas sp. S1-8; 该菌株降解Phe的最适盐浓度(NaCl)为5%，pH为8.0，温度为30℃。在盐浓度低于5%时，随着盐度的增加，菌株S1-8在盐碱胁迫下对Phe的降解动力学，符合一级降解动力学模型。菌株S1-8对盐浓度和环境酸碱度具有较广的适应范围，分别为NaCl含量0～30%和pH(6.0～11.0)。Halomonas sp. S1-8在湿地油田污染的生物修复中具有潜在的应用前景。研究成果发表于《土壤与作物》，项目实施期间设计的一种可用于土壤学研究的3D打印土壤孵育器，获得了实用新型专利（ZL202021004344.7）。