Abstract

Petroleum hydrocarbons (PHCs) in petroleum refinery sludge (PRS) are the most adverse components because of their toxic nature, which are harmful to human health and the aquatic ecosystem. This study aimed to identify and characterize an indigenous bacterium isolated from PRS of Indian oil corporation ltd. (IOCL), Haldia, India, and evaluate its performance for biodegradation of total petroleum hydrocarbon (TPH) of PRS. The bacterium molecularly characterized as Stenotrophomonas sp. IRB19 by 16S rRNA sequencing and phylogenetic analysis. The strain IRB19 showed a significant ability to utilize four different oils (kerosene, diesel, petrol and hexadecane) in-vitro. IRB19 could able to degrade up to 65 ± 2.4% of TPH in 28 d of incubation. Solvent extraction study showed that PRS contain 180.57 ± 3.44 g kg⁻¹ of TPH and maltene fraction composed of aliphatic, aromatics and polar components of 52 ± 4, 39 ± 2 and 9 ± 1%, respectively. The TPH degradation best fitted for the Gompertz model and followed the first-order kinetics having the rate constant (k) and half-life period (t _1/2) of 0.036 d⁻¹ and 19 d, respectively. Results of this study verified the suitability of the novel strain IRB19 for the biodegradation of PHCs.

摘要

炼油厂污泥（PRS）中的石油碳氢化合物（PHC）是最不利的成分，因为它们的毒性性质，对人体健康和水生生态系统有害。这项研究旨在鉴定和表征从印度石油公司PRS分离的本地细菌。（IOCL），印度哈尔迪亚，并评估其对PRS的总石油烃（TPH）进行生物降解的性能。该细菌的分子特征为嗜单胞菌。IRB19通过16S rRNA测序和系统发育分析。IRB19菌株显示出显着的体外利用四种不同油（煤油，柴油，汽油和十六烷）的能力。。在孵育28天后，IRB19可以降解高达65±2.4％的TPH。溶剂萃取研究表明，PRS含有180.57±3.44 g kg ^-1的TPH和由脂肪族，芳香族和极性成分分别为52± 4、39 ±2和9±1％组成的麦芽烯馏分。TPH降解最适合Gompertz模型，并遵循一级动力学，其速率常数（k）和半衰期（t _1/2）分别为0.036 d ^-1和19 d。这项研究的结果证实了新菌株IRB19对PHCs的生物降解的适用性。