生物表面活性剂强化微生物修复多环芳烃污染土壤的初探

EFFECT OF BIOSURFACTANT ENHANCING BIOREMEDIATION OF POLYCYCLIC AROMATIC HYDROCARBONS(PAHs) CONTAMINATED SOILS

通过温室盆栽实验,单独或联合接种多环芳烃专性降解菌(DB)和添加生物表面活性剂-鼠李糖脂(RH),研究了生物表面活性剂强化微生物修复多环芳烃(PAHs)长期污染土壤的效果。结果表明,添加RH和接种DB能明显促进土壤中PAHs总量和各组分PAHs的降解。经过90 d培养后,添加RH、DB和RH+DB处理的PAHs的降解率分别为21.3%、32.6%、36.0%,较对照分别提高了333.0%、563.3%、633.0%。此外,随着苯环数的增加,土壤中15种PAHs平均降解率逐渐降低。同时也发现DB、RH+DB处理土壤中脱氢酶活性、多酚氧化酶活性和PAHs降解菌数量显著高于CK、RH处理,但是CK与RH处理没有显著差异,说明DB、RH在促进土壤中PAHs的降解方面有不同的机制。

A pot experiment in greenhouse was carried out to investigate effects of application of rhamnolipid（RH）,a type of biosurfactant on the effect of PAHs-specific degrading bacteria（DB） in bioremediation of soils that have long been contaminated by PAHs.Results indicate that application of RH in addition to DB inoculation significantly increased total PAHs and promoted degradation of PAHs different in number of rings in the soil.After 90 days of incubation,the PAHs degradation ratio of Treatments RH,DB and RH＋DB reached 21.3%,32.6% and 36.0%,respectively,and increased by 333.0%,563.3% and 633.0% as compared against that（4.9%） of the control.In addition,the average PAHs degradation ratio declined with the number of rings of the 15 PAHs.It was also found that the number of PAHs degrading bacteria,dehydrogenase activity and polyphenol oxidase activity in soils of Treatments DB and RH＋DB were much higher than in Treatment RH and in CK,but differed slightly between Treatment RH and CK,suggesting that the mechanism of DB promoting degradation of PAHs in the soil is different from that of RH.