盐胁迫对石油污染土壤生物强化修复过程的影响

Influence of salt stress on bio-enhanced remediation of petroleum contaminated soil

在添加外源耐盐石油烃降解菌Staphylococcus 2-24的基础上,研究了1.0%、2.0%、3.0%NaCl与土壤中石油烃降解率、对应微生物数量、微生物菌群结构及优势菌变化的关系。结果显示,特定的菌群在高盐中(3.0%NaCl)的定殖能力强于低盐环境(1%NaCl);石油烃的降解率、可培养微生物总数及石油烃降解菌的数量与盐度呈负相关;菌群丰度及多样性在修复前期与盐度相关性较小,修复后期与盐度正相关;盐胁迫显著影响了菌群结构及优势属的相对丰度,盐胁迫下优势属为KCM-B-112、Halomonas、Virgibacillus,菌群结构及优势属随修复时间的推移而变化。

The corresponding relationship between the concentrations(1%,2%and 3%)of NaCl in the soil respectively and the degrading rate of petroleum hydrocarbons in the soil,corresponding microbial quantity,microbial flora structure and dominant bacteria change are studied on the basis of adding with salt-tolerant degrading strain Staphylococcus2-24 during the remediation process.The result shows that a specific flora represents a stronger colonization ability in high salt environment(3.0%NaCl)than that in low salt environment(1%NaCl).The degrading rate of petroleum hydrocarbons,total number of culturable microorganisms and the number of degrading bacteria for petroleum hydrocarbon are all negative correlation with NaCl concentration.The abundance and diversity of microflora have little correlation with NaCl concentration in the early stage of remediation,and have a positive correlation with NaCl concentration in the late stage of restoration.Salt stress affects significantly the structure of microflora and the relative abundance of dominant bacteria.KCM-B-112,Halomonas and Virgibacillus are the dominant bacteria under salt stress.Salinity changes the bacterial community structure under the experimental conditions,and both the flora structure and the dominant bacteria change with the degradation process of petroleum hydrocarbons in the soil.