高效稠油降解菌DL1-G的筛选及降解特性

从大连保税库区稠油污染土壤中分离出1株稠油降解菌DL1-G,经形态观察、生化鉴定、16S rRNA序列及系统发育分析,鉴定该菌株为弯曲芽孢杆菌(Bacillus flexus).菌株DL1-G在第9d对稠油的降解率为39.89%,饱和烃和芳香烃的总含量降低了68.30%;GC-MS分析显示,饱和烃中nC11~nC38、nC6~nC30-烷基环已烷及姥鲛烷(27.179min)、植烷(30.657min)降解完全、未检出,C14~C16二环倍半萜烷及8α(H)-补身烷、8β(H)-补身烷、8β(H)-升补身烷降解率达99%以上,13β(H),14α(H)-C19~C29三环萜烷共降解了36.32%,11种甾烷类化合物共降解了12.04%;芳烃中萘系物、菲系物、芴系物、二苯并噻吩系物、联苯系物、甲基芘系物等都有不同程度降解,其中萘系物、芴系物、二苯并噻吩系物的降解率均达90%以上;菌株DL1-G对多环芳烃(PAHs)中的蒽、菲、芴、芘、萘的降解率分别达98.55%、97.16%、82.98%、64.85%、63.61%,表明该菌株在稠油污染治理方面具有良好的应用潜力.

Isolation and degradation properties of heavy oil-degrading strain Bacillus flexus DL1-G

A bacterial strain DL1-G able to effectively degrade heavy oil was isolated from heavy oil-contaminated soil in the Dalian Bonded Area.The strain was identified to Bacillus flexus through morphological observation,physiological characteristics,16S rRNA gene sequence and phylogenetic tree analysis.The results showed that the degradation rate of 1g/L heavy oil was 39.89%,the total absolute contents of saturated and aromatic hydrocarbons was decreased by 68.30%.The saturated hydrocarbon nC11～nC38,nC6～nC30-alkyl cyclohexanes,pristine,phytane were undetected by gas chromatography-mass spectrometry(GC-MS) after biotreatment,more than 99% C14～C16-bicyclic sesquiterpanes,8α(H),8β(H)-Drimane degraded,13β(H),14α(H)-C19～C29-tricyclic terpanes and 11 kinds of steroidal compounds degraded by 36.32% and 12.04%,respectively.Among the aromatic hydrocarobons,more than 90% naphthalene series,fluorene series,dibenzothiophene series were degraded,anthracene,phenanthrene,fluorine,pyrene and naphthalene were degraded by 98.55%、97.16%、82.98 %、64.85%、63.61%,respectively,indicating strain DL1-G might play a significant role in biotreatment of heavy oil pollution.