石油污染土壤生物修复中外源微生物的影响

在室外条件下采用正交盆栽试验设计,以污染水平、细菌接种量、真菌接种量和有机肥添加量为调控因子,研究了石油污染土壤生物修复过程中外源专性微生物(细菌和真菌)接种对土壤中矿物油和美国EPA 16种多环芳烃(PAHs)降解的作用.结果表明,经过一个生长季(150d)各处理土壤中的细菌总量、真菌总量、PAH-降解细菌和PAH-降解真菌数量不受外源专性细菌和真菌初始接种量的影响(p＞0.05);有机肥促进土壤微生物数量的增长,其添加量与土壤细菌总量、真菌总量和PAH-降解细菌数量显著正相关(p＜0.05);实验结束时矿物油的去除率为58.8%～88.3%,PAHs的去除率为91.7%～97.8%,外源专性细菌和真菌的接种对矿物油和PAHs的降解无明显促进作用.

Limited effect of introduced microbial inoculants in the bioremediation of petroleum-contaminated soils

Bacteria and fungi were isolated from a long-term petroleum-contaminated site and their potential to enhance the degradation of mineral oil and 16 polycyclic aromatic hydrocarbons (PAHs) during the bioremediation of diesel-contaminated soil was estimated by means of outdoor pot cultivation. The factors adjusted included contamination level, bacterial inoculation volume, fungal inoculation volume, and manure addition. After one growth season (about 150 days) the initial introduced bacterial and fungal inoculants had no influence on the number of total bacteria, total fungi, PAH-degrading bacteria, and PAH-degrading fungi in each treatment ( p >0.05). Manure addition significantly promoted the increase of soil microorganisms, including total bacteria, total fungi, and PAH-degrading bacteria ( p <0.05). At the end of the test, the removal ratios were 58.8% to 88.3% for mineral oil, and 91.7% to 97.8% for the 16 PAHs listed by the US EPA. No advantages to the degradation of mineral oil and PAHs were achieved by the inoculation of either introduced bacteria or fungi, thus indicating their limited ability to compete in degrading contaminants.