微生物-植物联合修复，将微生物修复与植物修复的优点相结合，利用自然环境中植物根系对微生物生长的促进作用，有效地提高石油类污染物的微生物降解率，所以植物与微生物二者的联合作用对石油污染物的降解研究已成为近年来新的研究热点之一。本研究筛选柴油、芘为研究底物，从长期受石油污染的土壤中分别分离、筛选得到针对柴油和芘降解的菌株，围绕植物强化微生物降解土壤石油类污染物的新技术原理，研究植物-微生物联合修复土壤柴油、芘的效率及机制，探讨了植物吸收积累、微生物降解土壤中柴油、芘的相对贡献率。主要成果如下：（1）通过筛选，分离出3株对柴油降解效果最佳的菌株Q10、Q14和Q18以及2株对芘降解效果最佳的菌株B6和B17。结合Biolog自动菌种鉴定仪分析结果，初步确定菌株Q10、Q14、Q18、B6和B17分别为单胞菌（Pseudomonas sp.）、黄杆菌(Flavobacterium sp.)和红球菌(Rhodococcus sp.) 、球形芽孢杆菌（Bacillus sp.）、假单孢菌属(Pseudomonas sp.）（基因吻合度87%～99%）。（2）与菌株单独降解柴油相比，种植植物苜蓿、芥菜后菌株Q10、Q14及Q18对土壤中柴油污染物降解能力均有不同程度的提高。在本实验条件下，苜蓿和芥菜都不能有效降解柴油污染物，苜蓿和芥菜可能主要起到改善土壤环境、强化菌株Q10、Q14和Q18降解柴油的作用。苜蓿和芥菜强化菌株降解能力上并不相同，在砂土中，苜蓿强化菌株Q18降解柴油的能力强于芥菜；而在砂壤土和粘土中，芥菜强化菌株Q18降解柴油的能力强于苜蓿。在本实验中，菌株Q18-芥菜复合体在沙壤土中降解柴油能力最强（69.2％）。（3）植物可以从土壤中吸收PAHs，总体而言，芥菜的吸收PAHs能力强于苜蓿。另外，苜蓿和芥菜吸收芘的能力均强于菲。本实验条件下，苜蓿和芥菜吸收的菲和芘主要累积在植物根系，向植物地上部分传输的量很小。（4）土壤中种植植物苜蓿后，芘的去除率明显得到提高（20d时去除率为43.49%），均高于单纯植物修复和微生物修复。种植苜蓿土壤中过氧化氢酶和多酚氧化酶活性要高于不种植苜蓿土壤。种植苜蓿后，在基质土壤和根际土壤的菌株数量都有较大的提高，且根际土壤的菌株数量大于基质土壤。可见，植物苜蓿除了能通过自身能吸收而去除芘外，还能通过改善土壤环境，起到强化微生物降解芘的作用。

With the expansion of the oil-pollutant soil, the work on the treatment of oil pollutant in soil has great developed in different degree and area, especially biotechnology by using microbe advanced rapidly. But because the components of the oil and the process of the degradation are more complicated we do not entirely understand the universal law to increase the degradation efficiency in oil treatment.Using diesel oil and pyrene as unique carbon source,repectively, take soil sample from sewage control factory and gas station, microbe having the capacity of desulphurization was selected and named as Q10, Q14, Q18, B6 and B17. After isolation, purification this microbe as well as detection of its appearance, physiological and biochemical characteristics, growth characteristics, it was identified Pseudomonas sp., Flavobacterium sp., Rhodococcus sp., Bacillus sp. and Pseudomonas sp. according to bacteriological analytical manual (FDA) and taxology of microorganism.And the plants, alfalfa and Indian mustard, do improve the effectiveness of diesel oil biodegradation. Both of them along with bacteria exhibited more effective degradation of diesel oil than isolates alone. The diesel oil biodegradation due to combination of the plants and the bacteria go up to 69.2%. Indian mustard shows more effective in the improvement of the biodegradation of diesel oil than alfalfa. The strain Q18 had the greatest degradation ability for diesel oil in sandy loam. Both alfalfa and mustard along with bacteria was more effective in degradation of diesel oil than bacteria alone. Mustard resulted in the maximum diesel oil reduction in sandy loam and clay, but alfalfa resulted in the maximum diesel oil reduction in sandy.It was also indicated that the P6-alfalfa association was more effective in removal of pyrene. The pyrene was also both detected in the shoots and roots of alfalfa, and more pyrene was accumulated in the roots than those in the shoots. Through analysis of pathways of pyrene removal, this enhanced removal of pyrene by plant-microbial association might be the result of alfalfa promoted microbial degradation. The POD (peroxidase) in plant roots was generally higher than that in shoots. In contrast, the PPO (phenol oxidase) in roots was lower than that in shoots. The catalase and polyphenol oxidase activities in soil were both higher in planted soil than unplanted soil. And the bacteria populations in soil, especially in rhizosphere were also inspired by the growth of alfalfa. These could be explained by the rhizosphere effect. This enhanced dissipation of pyrene in planted soil might be due to increased biological activity in the rhizosphere.