ABSTRACT This work studied the biodegradation of petroleum hydrocarbons (PHCs) extracted from refinery wastewater to produce industrially important by-products at different incubation periods. Two out of 13 bacterial isolates, KRD2 and KRA4 were isolated. Dichloromethane was used to extract the PHC, and gas chromatography-mass spectrometry (GC-MS) analysis revealed that the refinery wastewater PHC was successfully biodegraded using the selected bacterial isolates within 15 days of incubation. Both KRD2 and KRA4 isolates degraded all 13 initially extracted PHC compounds within 5 days, except C13BD and C9BD, which produced 6 and 4 compounds as secondary metabolites with peak area percentages of 1.58, 1.38, 0.85, 29.94, 7.59, and 11.16% and 3.55, 2.88, 52.31, and 6.14%, respectively. These metabolites have been reported in industrial and medical applications. After 10 days, only 6 and 8 compounds were degraded by both isolates, respectively, and C11PAD compound was produced, as well as C5PAD, C7PAD, and C13PAD. After 15 days, it was clear that all the initial PHC compounds have been completely degraded by both isolates. Metabolites C5PAD, C6PAD, C8PAD, and C13PAD were produced by KRD2, and metabolites C5PAD, C6PAD, C8PAD, and C9PAD were produced by KRA4 at different peak areas. The alignment revealed that the KRA4 isolate was included in the genus Chryseobacterium gambrini, while KRD2 isolate was successfully identified as Mycobacterium confluentis using the Biolog microbial identification system. The incubation period evidently affected biodegradation process by indigenous degraders. These effective bacteria were shown to be of great potential for further application in biodegradation technology of PHC contaminated refinery wastewater to produce industrially important by-products.

中文翻译：

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潜伏期对马来西亚关丹炼油厂废水中石油烃生物降解的影响

摘要 这项工作研究了从炼油厂废水中提取的石油烃 (PHC) 的生物降解，以在不同的潜伏期生产具有重要工业意义的副产品。分离出 13 个细菌分离株中的两个，KRD2 和 KRA4。使用二氯甲烷提取 PHC，气相色谱-质谱联用 (GC-MS) 分析表明，在孵育 15 天内，使用选定的细菌分离物成功生物降解炼油厂废水 PHC。KRD2 和 KRA4 分离株均在 5 天内降解了所有 13 种最初提取的 PHC 化合物，但 C13BD 和 C9BD 产生了 6 和 4 种化合物作为次级代谢物，峰面积百分比分别为 1.58、1.38、0.85、29.94、7.59 和 11.155% 和 3 、2.88、52.31 和 6.14%。这些代谢物已在工业和医疗应用中得到报道。10 天后，两种分离物仅分别降解了 6 和 8 种化合物，并产生了 C11PAD 化合物，以及 C5PAD、C7PAD 和 C13PAD。15 天后，很明显所有初始 PHC 化合物都已被两种分离物完全降解。代谢物 C5PAD、C6PAD、C8PAD 和 C13PAD 由 KRD2 产生，代谢物 C5PAD、C6PAD、C8PAD 和 C9PAD 由 KRA4 在不同的峰面积产生。比对显示 KRA4 分离物包含在金黄色金黄色葡萄球菌属中，而 KRD2 分离物使用 Biolog 微生物鉴定系统成功鉴定为汇合分枝杆菌。潜伏期明显影响本地降解者的生物降解过程。