石油降解菌群的构建及其对混合烃的降解特性

经富集、分离、纯化,并经选择性培养基的筛选和对总石油烃(TPH)降解能力的测试,从大庆油田石油污染土壤中获得6株分别具有环烷烃、直链烷烃和芳烃降解能力的菌株B_1、B_2、B_3、B_6、B_7和B_9。经16S r RNA基因序列比对,菌株B_1、B_2、B_6和B_7分别属于嗜氢菌属(Hydrogenophaga sp.)、苯基杆菌属(Phenylobacterium sp.)、鞘脂菌属(Sphingobium sp.)和芽胞杆菌属(Bacillus sp.),B_3和B_9属于节杆菌属(Arthrobacter sp.)。通过对接种比例、接种量和生长条件的优化,构建了微生物降解菌群,并采用该菌群进行混合烃污染土壤的修复。结果表明,该菌群对三类烃的去除均具有明显的促进作用。经过40 d的修复,环十二烷去除率达74.5%;100 d后,正十六烷和芘的去除率分别达56.9%和60.4%。前10 d修复过程中,各污染物降解速率最大,之后则逐渐降低,与土壤微生物多样性、数量以及活性的变化趋势相似。

Construction of petroleum degrading bacteria consortium and its degradation properties of mixed hydrocarbons

After enrichment, separation, purification, screening by selective medium, and testing by degradation ability of the total petroleum hydrocarbon(TPH), 6 strains(B₁, B₂, B₃, B₆, B₇ and B₉) with cyclanes, alkanes, and aromatics degradation ability were obtained. Based on the sequence analysis of 16S rRNA gene, B₁, B₂, B₆ and B₇ were identified as Hydrogenophaga sp., Phenylobacterium sp., Sphingobium sp. and Bacillus sp., respectively; B₃ and B₉ were identified as Arthrobacter sp.. A microbial degradation flora was constructed through the optimization of the inoculum proportion, size, and growth conditions. The degradation flora was then used in the remediation of mixed hydrocarbon-contaminated soil, the results demonstrated an obvious effect of the flora in the degradation of three kinds of hydrocarbons. After 40 d of remediation, the degradation extent of cyclododecane can be reach to 74.5%; and after 100 d, the degradation extents of n-hexadecane and pyrene reached to 56.9% and 60.4%, respectively. There was a significant decrease of pollutants during the first 10 d, and the removal efficiency was reduced along with the experiment, showed a similar variation tendency with microbial diversity, quantity and activity in soil.