Abstract

Accretion of polycyclic aromatic hydrocarbons in environment due to variety of anthropogenic activities has taken this ecosystem to the brink of destruction. Since the dawn of century, various physio-chemical methods have been postulated for the removal of these noxious substances. So far, microbial degradation is a most effective way to get rid of this ecological problem. Therefore, the assessment of randomly nominated soil samples from different sites of country land (Pakistan) was performed to scrutinize the proficiency of indigenous bacteria in degrading hydrocarbons (Hi-Octane, petrol, kerosene oil, and lubricating oil). The statistically based Plackett–Burman experimental design was also applied to evaluate the cultural conditions affecting degradation potency. Potential isolates were identified through biochemical and molecular analysis followed by the Gravimetric test to estimate the degradation level. In addition, the isolated strains exhibited a significant production of bio-surfactants in their cell-free condition. Five potent strains including Streptococcus sp., Bacillus flexus, Arthrobacter sp., Bacillus sp., and Ancyclobacter rudongensis were screened out, which have an ability to degrade and utilize kerosene oil, Hi-octane, petrol, and lubricating oil when analyzed individually. However, the bacterial consortium of all five strains (AA1-5) exhibited prodigious efficiency to degrade variety of hydrocarbons in less time.

摘要

由于各种人为活动，环境中多环芳烃的增加已将该生态系统带到了破坏的边缘。自本世纪初以来，人们提出了各种物理化学方法来去除这些有毒物质。迄今为止，微生物降解是摆脱这一生态问题的最有效方法。因此，对来自乡村土地（巴基斯坦）不同地点的随机指定的土壤样本进行了评估，以仔细检查本地细菌在降解碳氢化合物（高辛烷值、汽油、煤油和润滑油）方面的能力。基于统计的 Plackett-Burman 实验设计也用于评估影响降解效力的培养条件。通过生化和分子分析确定潜在的分离株，然后进行重量测试以估计降解水平。此外，分离的菌株在无细胞条件下表现出大量的生物表面活性剂。五种有效菌株，包括筛选出链球菌属、弯曲杆菌属、节杆菌属、芽孢杆菌属和如东环杆菌属，单独分析时具有降解和利用煤油、高辛烷值、汽油和润滑油的能力。然而，所有五种菌株 (AA1-5) 的细菌聚生体表现出惊人的效率，可以在更短的时间内降解各种碳氢化合物。