石油降解菌株的分离鉴定及降油特性

从甘肃华庆油田污染严重的土壤中采样,通过富集培养、多次筛选分离得到1株优势菌F1。依据生理生化特征和16S rDNA序列将菌株F1鉴定为白色类诺卡氏菌(Nocardioides albus)。GS-MC结果表明,等量原油经F1菌株降解前、后,表现出先降解高碳数正构烷烃为低碳数正构烷烃;高碳数正构烷烃中奇数碳向偶数碳正构烷烃演化规律;平均降油率为64%,F1菌株能较好地促使五环三萜类化合物立体构型中不稳定构型向稳定性构型转化。F1菌株在含油浓度0.3%、0.5%、1.0%土样中降解石油烃的半衰期分别为17.2、18.2、23.7 d,42 d后均达到78%以上。

Isolation and Identification of Petroleum-Degradable Bacterial Strain and Its Oil-Degradation Characteristics

An oil-degradation bacterial dominant strain F1 was screened and isolated from seriously oil-contaminated soil sampled at Huaqing Oilfield in Gansu Province through enrichement cultivation and multiple screening.Based on physio-biochemical characters and 16S rDNA sequencing indicate that the strain F1 was identified preliminarily as Nocardioides albus.The general law is that after treated with strain F1,the higher molecular weight n-alkanes were degradated into lower molecular weight n-alkanes,and the n-alkanes in odd-numbered carbon were degradated into n-alkanes in even-numbered carbon,as revealed by GS-MC.The average oil-degradation rate was 64%,and the strain F1 could promote the transition from less stable configuration in pentacyclic triterpenes to stable one.In addition,it was shown that the TPH degradation rate of the strain F1 was higher than 78% after 42 days,the degradation half-life of petroleum were about 17.2、18.2、23.7 days under different petroleum-contaminated soils respectively.