Isolation and characterization of hydrocarbon-degrading bacteria from gas station leaking-contaminated groundwater in the Southern Amazon, Brazil

Abstract Twenty-three hydrocarbon-degrading bacteria strains were isolated from gas station leaking-contaminated groundwater located in the Southern Amazon, Brazil. Based on hydrocarbon (diesel, hexadecane, benzene, toluene and xylene) degradation ability, two strains were selected for further study. The amplification and sequencing of the 16S rRNA gene showed that these two strains belonged to the genus Bacillus (Bacillus sp. L26 and Bacillus sp. L30). GC-MS analysis showed that strain L30 was the most effective in degrading n-alkane (C10-C27) from diesel after 7 days of cultivation in mineral medium. Both strains produced biosurfactants and showed emulsification activity, specially the strain L30. Alkane hydroxylase gene (group III), which is important for alkane biodegradation, was present in strains. As a result, this study indicated that these bacteria could have promising applications in hydrocarbon bioremediation.

摘要 从巴西亚马孙南部某加油站泄漏污染的地下水中，分离得到23株烃降解细菌菌株。基于对柴油、十六烷、苯、甲苯、二甲苯等烃类的降解能力，筛选出2株菌株开展后续研究。对16S核糖体RNA基因（16S rRNA gene）进行扩增与测序后发现，这两株菌株均隶属于芽孢杆菌属（Bacillus），分别为Bacillus sp. L26与Bacillus sp. L30。气相色谱-质谱联用（GC-MS）分析结果显示，在矿物盐培养基中培养7天后，L30菌株对柴油中的正构烷烃（C10-C27）降解效果最佳。两株菌株均可产生生物表面活性剂并表现出乳化活性，其中L30菌株的该特性尤为突出。两株菌株均携带烷烃生物降解过程中的关键功能基因——Ⅲ族烷烃羟化酶基因。本研究结果表明，上述菌株在烃类污染生物修复领域具有良好的应用前景。