苯并[a]芘降解菌SL-1的筛选、鉴定及其降解特性

LSOLATION,IDENTIFICATION AND DEGRADATION PROPERTIES OF A BENZO[a]PYRENE-DEGRADING STRAIN SL-1

从土壤中筛选出一株以苯并[a]芘为唯一碳源的高效降解菌SL-1,经形态观察、生理生化分析以及16S rDNA基因序列分析,该菌株鉴定为假单胞菌(Pseudomonas sp.)。28℃震荡培养10 d后,菌株SL-1对5mg.L-1苯并[a]芘的降解率为35.7%;同时测定该降解菌的生长曲线、降解率变化曲线、最佳培养条件;土壤修复试验表明,42d时,降解菌SL-1对苯并芘的降解率达到76.3%。

A bacterium strain SL - 1 was isolated from. soil by repeated subculture in liquid medium with benzo [a] pyrene as sole earbon source. To confirm the classification of SL - 1, morphological, physiological and biochemical characterization were applied and PCR was carried out to measure the gone sequence of 16S rDNA. The 16S rDNA was compared with related bacterias in GenBank, and phylogenetic tree was constructed. Based on the above results, the strain SL - 1 was identified as Pseudomonas. sp.. In a mineral salts medium with 5 mg . L - 1 benzo [a] pyrene, the highest degradation rate of 35.7% was obtained after 10 days at 28 ℃ ; and varied curves of growth, degradation rate,optimal conditions of growth. Experiments for bioremediation of bcnzopyrene - contaminated soil were detected, Within 42 days, the degrading rates were 76.3% respectively.