不同种类食细菌线虫对石油污染土壤微生物的影响

通过在石油污染土壤中接种不同种类食细菌线虫，探究土壤微生物活性和多样性的变化.本试验设置5个处理：杀灭线虫土壤（NFS）、石油污染土壤（SP）、在石油污染土壤中分别接种不同线虫，即秀丽隐杆线虫（Caenorhabditis elegans，SPN1）、头叶属线虫（Cephalobus persegnis，SPN2）和小杆属线虫（Rhabditis marina，SPN3）.结果表明，经过168d试验，和NFS相比，SP的土壤基础呼吸和脲酶活性增大，而微生物量碳含量和蔗糖酶活性减小.和SP相比，SPN1、SPN2、SPN3的基础呼吸增大，微生物量碳减少了34.59%~72.48%，蔗糖酶活性增加了15.66%~22.89%.SP、SPN1、SPN2和SPN3的微生物的丰富度（S）分别下降了5.00，7.25，2.50和9.75，Shannon-Wiener指数（H'）分别显著下降了0.18，0.15，0.15和0.23.不同种类的食细菌线虫可通过捕食作用对石油污染土壤微生物活性及多样性产生影响并有种间差异，有利于提高石油污染土壤微生物活性，促进石油降解.

Effects of different speices of bacterial-feeding nematodes on soil microorganisms in oil-contaminated soils

The effects of different species of bacterial-feeding nematodes on soil microbial activity and diversity in oil-contaminated soil were studied in an effort to provide a preliminary theoretical basis and a new research perspective for the bioremediation of oil-contaminated soil. Five treatments were set up in our experiment:nematode-free soil (NFS), oil-contaminated soil (SP), oil-contaminated soil + Caenorhabditis elegans (SPN1); oil contaminated soil + Cephalobus persegnis (SPN2); oil contaminated soil + Rhabditis marina (SPN3). After 168d of the experiment, the findings were as follows:the soil basal respiration and microbial biomass carbon of SP increased due to oil pollution, while the activities of urease and sucrase decreased, and the richness, diversity index and evenness index of microorganisms decreased too. Compared with SP, the basal respiration of SPN1, SPN2 and SPN3 inoculated with nematodes increased, while the microbial biomass carbon decreased by 34.59% to 72.48%, and the sucrase activity increased by 15.66% to 22.89%. Relative to 0d, the microbial richness (S) of SP, SPN1, SPN2 and SPN3 decreased by 5, 7.25, 2.5 and 9.75, respectively, and the shannon-wiener index (H') decreased by 0.18, 0.15, 0.15 and 0.23. The results demonstrated that different species of bacterial-feeding nematodes helped to improve the microbial activity in oil-polluted soil and enhance the oil degradation through predation.