Abstract:

In order to improve the effectiveness of microbial treatment of oily sludge, this study screened 4 efficient petroleum hydrocarbon degrading bacteria R, J, C and K from oilfield oily sludge, and identified them as Pseudomonas aeruginosa, Candida tropicalis, Rhodococcus erythropolis, and Bacillus subtilis through 16S rDNA. These strains of bacteria could metabolize biosurfactants and had good degradation performance on crude oil. Through antagonistic experiments, surface tension measurements, and analysis of the degradation performance of different components of petroleum hydrocarbons, combined with the principle of complementary advantages, it was ultimately determined to combine strains R, K, J, and C in a ratio of 1∶1∶1∶1 to construct an efficient composite degradation microbial community. The composite microbial community could exert synergistic effects among different strains, further improving the degradation performance of petroleum hydrocarbons. Under the same conditions, the degradation rate of petroleum hydrocarbons reached 91.2%, which was significantly better than that of a single strain. Through field application, it was found that after 60 days of composite microbial community bioaugmentation treatment, the oil content in the soil decreased from the initial 4.97% to 0.34%, meeting the national second class standard for arable land. This indicated that the microbial community had broad application prospects in the remediation of oily soil.

Key words: oily soil, microbial remediation, biodegradation, bacterial screening, construction of composite microbial communities

摘要：

为提高微生物修复含油土壤效果，本研究从油田含油土壤中筛选出4株高效石油烃降解菌R、J、C及K，通过16S rDNA分别鉴定为铜绿假单胞菌、热带假丝酵母菌、红城红球菌和枯草芽孢杆菌。这几株菌均能代谢生物表面活性剂，并对原油具有良好的降解性能。通过拮抗实验、表面张力测定以及对石油烃不同组分的降解性能分析，并结合优势互补原则最终确定将菌株R、K、J和C按1∶1∶1∶1进行复配以构建高效复合降解菌群。复合菌群能够发挥不同菌株之间的协同作用，进一步提高其对石油烃的降解性能，在相同条件下对石油烃降解率达到91.2%，明显优于单菌株。通过现场实验发现，采用复合菌剂对含油土壤进行生物强化处理60d后，土壤中的含油量从初始的4.97%下降到了0.34%，达到国家耕地二类标准，表明该菌群在含油土壤修复方面具有广阔的应用前景。

关键词: 含油土壤, 微生物修复, 生物降解, 菌种筛选, 复合菌群构建