Nisar Nimra, Fareed Anum, Naqvi Syed Tatheer Alam, Zeb Bibi Saima, Amin Bilal Ahmad Zafar, Khurshid Ghazal, Zaffar Habiba
Department of Environmental Sciences, COMSATS University Islamabad, Abbottabad Campus, Abbottabad 22060, Pakistan.
Department of Biotechnology, COMSATS University Islamabad, Abbottabad Campus, Abbottabad 22060, Pakistan.
ACS Omega. 2024 Dec 31;10(1):541-549. doi: 10.1021/acsomega.4c06964. eCollection 2025 Jan 14.
Used engine oil is considered to be one of the high-risk pollutants, and if introduced untreated in the environment, it threatens the whole ecosystem. Therefore, there is a need to find some rapid and efficient methods for the remediation of used engine oil. The present study aimed to isolate indigenous bacterial strains having the capability to degrade used engine oil. The enrichment technique was employed for the isolation of bacterial strains, which were identified by the 16S rRNA technique. As biosurfactants play a vital role in the degradation process, the activity was determined by standard protocols. The bacterial strain was isolated by the enrichment technique and identified as the strain NMA. The bacterial isolate has the ability to utilize used engine oil as the sole source of energy. The biodegradation experiment revealed that both free and immobilized cells degrade used engine oil, but immobilized cells showed the best biodegradation result, with 98-99% degradation efficiency in 7 days of incubation irrespective of all oil concentrations. For the analysis of degraded products, gas chromatography-mass spectrometry (GC-MS) was performed, which indicates that the treated samples do not carry the major engine components, i.e., methyl hexane, pyrene, and phytane, which confirmed that these were transformed by the bacterial activity. Monod kinetics further confirmed that the isolated bacterium utilizes used engine oil as the sole source of energy. These findings clearly indicate the potential of the bacterium NMA to degrade used engine oil with high kinetics, converting it into nontoxic products, and thus be a potential candidate for remediation at contaminated sites.
废机油被认为是高风险污染物之一，如果未经处理排放到环境中，会威胁到整个生态系统。因此，需要找到一些快速有效的方法来修复废机油。本研究旨在分离出具有降解废机油能力的本地细菌菌株。采用富集技术分离细菌菌株，并通过16S rRNA技术进行鉴定。由于生物表面活性剂在降解过程中起着至关重要的作用，其活性通过标准方法测定。通过富集技术分离出细菌菌株，鉴定为NMA菌株。该细菌分离株能够将废机油作为唯一能源利用。生物降解实验表明，游离细胞和固定化细胞都能降解废机油，但固定化细胞表现出最佳的生物降解效果，在7天的培养期内，无论油浓度如何，降解效率都达到98 - 99%。为了分析降解产物，进行了气相色谱 - 质谱联用（GC - MS）分析，结果表明处理后的样品中不含有主要的发动机成分，即甲基己烷、芘和植烷，这证实了这些成分已被细菌活性转化。莫诺德动力学进一步证实，分离出的细菌将废机油作为唯一能源利用。这些发现清楚地表明了NMA细菌具有以高动力学降解废机油的潜力，能将其转化为无毒产物，因此是污染场地修复的潜在候选菌株。
