石油污染土壤的修复日益重要，细菌是污染土壤中降解石油的主要生物。食细菌线虫是土壤线虫的重要功能类群，可通过取食细菌影响微生物的数量、活性和群落结构，参与土壤的多种生态过程，但食细菌线虫如何调控细菌群落影响污染土壤石油降解的机理尚不清晰。本研究拟通过在不同土壤温度、湿度和有机质条件下,接种不同种类和密度的食细菌线虫，采用变性梯度凝胶电泳及末端限制性片段长度多态性技术，研究食细菌线虫作用下石油污染土壤细菌群落结构的变化；然后利用荧光原位杂交技术，探究食细菌线虫对石油降解菌数量的影响；在此基础上分析污染土壤石油降解与食细菌线虫及石油降解菌群落组成和数量的相关关系，确认在食细菌线虫与石油降解菌互作条件下影响石油降解的环境因子及生物学机理，明确食细菌线虫在石油污染土壤中的生态功能，为揭示食细菌线虫与石油降解菌之间的"牧食与促进作用"的分子生物学机制及发掘和利用调控石油降解的有益土壤生物提供理论基础。

The remediation of soil petroleum contamination is becoming increasingly important. Bacteria are the key organisms for petroleum degradation in contaminated soil and bacterial-feeding nematodes are the main functional group of soil nematodes. In addition to their roles in metabolic activity, soil bacterial-feeding nematodes are involved in soil ecological processes through grazing on soil bacteria, resulting in changes in the number of microbes, microbial activity and microbial community structure. However, the potential impact of bacterial-feeding nematodes on the petroleum degradation through grazing on soil bacteria is currently unknown. In this study, various species of bacterial-feeding nematodes in various densities will be inoculated into petroleum-contaminated soils with the following variable conditions: soil temperature, moisture and organic matrix. The impact of bacterial-feeding nematodes on the dynamic of bacterial community structure will be investigated using methods called denaturing gradient gel electrophoresis (DGGE) and terminal restriction fragment length polymorphism (T-RFLP). Further, the effect of bacterial-feeding nematodes on the number of petroleum-degrading bacteria in contaminated soil will be investigated using a method called fluorescence in situ hybridization (FISH) using specific oligonucleotide probe markers. The goal of this project is to reveal the role of bacterial-feeding nematodes in degrading petroleum in contaminated soils, to identify the environmental factors that are favorable for bacterial-feeding nematodes and petroleum-degrading bacteria enhancing the petroleum degradation, to explore the biological mechanisms of bacterial-feeding nematodes' influence on petroleum degradation, and to clarify the mechanisms of molecular biology for "grazing and enhancing" relationship between bacterial-feeding nematodes and petroleum-degrading bacteria. It is expected that all the research into this program will pave the way for discovery and rational use of beneficial soil organisms that can regulate the degradation of petroleum in soils.