氯氰菊酯污染土壤的微生物修复及对土著微生物的影响

MICROBIAL REMEDIATION OF CYPERMETHRIN-CONTAMINATED SOIL AND EFFECT ON SOIL MICROBIAL COMMUNITIES

在实验室条件下,在含有氯氰菊酯的土壤中添加氯氰菊酯和3-苯氧基苯甲酸(3-PBA)降解菌CDT3(Rhodococcussp.)和PBM11(Pesudomonassp.),同时设不加菌的对照。分别于0、3、7、15、30 d取样,测定土壤中氯氰菊酯和3-PBA的残留,同时用平板计数和变性梯度凝胶电泳(DGGE)方法分析土壤微生物群落的变化。结果显示:CDT3和PBM11在土壤中协同作用能够更好地降解氯氰菊酯及其中间产物3-PBA。氯氰菊酯对土著微生物有较强的抑制作用。投加降解菌可以消除农药对土壤微生物的抑制,有助于土著微生物种群的恢复,但短期内无法改变农药对土壤微生物结构的破坏。

An experiment was conducted in lab by inoculating cypermethrin-contaminated soil, separately, with cypermethrin,3-Phenoxybenzoic acid （3-PBA）-degrading bacteria CDT3 （Rhodoccus sp. ） and PBM11 （ Pesudomonas sp. ） to study their effects on microbial remediation of the contaminated soil and soil microbial communities. Samples were collected＇from the inoculated soils and CK （uninoculated） on D0, D3, D7, D15, and D30 for analysis of residues of cypermethrin and 3-Phenoxybenzoic acid（3-PBA）in the soil as well as monitoring of dynamics of the microbial communities in the soil, using the plate counting method and denaturing gradient gel electrophoresis（DGGE）method. The analysis results show that the cooperation of CDT3 and PBMll promoted the degradation of eypermethrin and its metabolite 3-PBA in the soil. As cypermethrin inhibits significantly native edaphon in soil, inoculation of these degrading-bacteria could eliminate the inhibitive effect of cypermethrin on edaphon, thus promoting restoration of indigenous microbial population and communities. But it could not be expected that the damage cypermethrin brings to the soil microbial structure could be removed within a short period of time.