两株石油烃降解菌的分离及原油降解地球化学特征

ISOLATION OF TWO PETROLEUM HYDROCARBON DEGRADING BACTERIA AND GEOCHEMICAL CHARACTERISTICS OF CRUDE OIL DEGRADATION

为研究在自然界条件下内源微生物降解原油的机理，从辽河原油中发现具有较强原油降解能力的混合菌种，进行分离纯化，选择3#和9#菌株进行原油降解实验研究。通过微生物降解模拟实验、降解后液体表面张力测定和原油降解前后饱和烃、芳烃GC—MS定量分析，将两菌株对原油不同组分的降解效果进行对比。结果表明，两菌株虽然不具备产表面活性剂的能力，但具有较强降解饱和烃的能力，且较易降解正构烷烃，同时发现9＃群菌株具更强的降解正构烷烃及姥鲛烷和植烷的能力，而3#菌株对三环萜烷和甾烷系列的降解能力较好。3#和9#菌株对萘系列和菲系列的降解效果均不明显，且对萘和菲系列的芳香烃化合物的降解有选择性。研究结果可为MEOR矿场试验及微生物修复提供依据。

In order to study the mechanism of crude oil degradation by indigenous microbes in the natural condition, the mixed strains with relatively strong degradation ability towards crude oil is discovered in Liaohe crude oil. After isolation and purification, 3# and 9# strains are selected to carry out the experimental study of crude oil degradation. Through the microbial degradation simulating experiments, the measurement of liquid surface tension after degradation and the GC-MS quantitative analysis of saturated crude oil degradation, the degradation effects of these two hydrocarbon and aromatic hydrocarbon before and after strains towards the different crude oil components are compared. The result shows that although the two strains do not have the ability of generating surfactants, they have the relatively strong ability of degrading saturated hydrocarbon and tend to degrade normal paraffin hydrocarbon more easily. Meanwhile, it is found that 9# strain has the relatively stronger ability of degrading normal paraffin hydrocarbon, pristane and phytane, however, 3# strain has the relatively better ability of degrading trieyelic terpane and gonane. Both 3# and 9# strains do not have an obvious degradation effect towards naphthalene and phenanthrene series, but they have selectivity for the degradation of aromatic compounds of naphthalene and phenanthrene series. This research result can provide evidences for MEOR field test and microbial restoration.