Adlan Nur Aina, Sabri Suriana, Masomian Malihe, Ali Mohd Shukuri Mohamad, Rahman Raja Noor Zaliha Raja Abd
Enzyme and Microbial Technology Research Centre, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, Serdang, Malaysia.
Department of Microbiology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, Serdang, Malaysia.
Front Microbiol. 2020 Sep 8;11:565608. doi: 10.3389/fmicb.2020.565608. eCollection 2020.
The deposition of paraffin wax in crude oil is a problem faced by the oil and gas industry during extraction, transportation, and refining of crude oil. Most of the commercialized chemical additives to prevent wax are expensive and toxic. As an environmentally friendly alternative, this study aims to find a novel thermophilic bacterial strain capable of degrading paraffin wax in crude oil to control wax deposition. To achieve this, the biodegradation of crude oil paraffin wax by 11 bacteria isolated from seawater and oil-contaminated soil samples was investigated at 70°C. The bacteria were identified as N3A7, NFA23, DFY1, MK7, T7, DFY3 and AZ72, D9, SA36, AD11, and AD24. The GCMS analysis showed that strains N3A7, MK7, DFY1, AD11, and AD24 achieved more than 70% biodegradation efficiency of crude oil in a short period (3 days). Notably, most of the strains could completely degrade C-C and increase the ratio of C-C, especially during the initial 2 days incubation. In addition, the degradation of crude oil also resulted in changes in the pH of the medium. The degradation of crude oil is associated with the production of degradative enzymes such as alkane monooxygenase, alcohol dehydrogenase, lipase, and esterase. Among the 11 strains, the highest activities of alkane monooxygenase were recorded in strain AD24. A comparatively higher overall alcohol dehydrogenase, lipase, and esterase activities were observed in strains N3A7, MK7, DFY1, AD11, and AD24. Thus, there is a potential to use these strains in oil reservoirs, crude oil processing, and recovery to control wax deposition. Their ability to withstand high temperature and produce degradative enzymes for long-chain hydrocarbon degradation led to an increase in the short-chain hydrocarbon ratio, and subsequently, improving the quality of the oil.
原油中石蜡的沉积是石油和天然气行业在原油开采、运输和精炼过程中面临的一个问题。大多数商业化的防蜡化学添加剂既昂贵又有毒。作为一种环保替代方案，本研究旨在寻找一种能够降解原油中石蜡以控制蜡沉积的新型嗜热细菌菌株。为实现这一目标，在70°C下研究了从海水和受油污染土壤样品中分离出的11种细菌对原油石蜡的生物降解作用。这些细菌被鉴定为N3A7、NFA23、DFY1、MK7、T7、DFY3和AZ72、D9、SA36、AD11以及AD24。气相色谱 - 质谱联用（GCMS）分析表明，菌株N3A7、MK7、DFY1、AD11和AD24在短时间内（3天）实现了超过70%的原油生物降解效率。值得注意的是，大多数菌株能够完全降解碳 - 碳键并增加碳 - 碳键的比例，尤其是在培养的最初2天。此外，原油的降解还导致了培养基pH值的变化。原油的降解与烷烃单加氧酶、醇脱氢酶、脂肪酶和酯酶等降解酶的产生有关。在这11种菌株中，菌株AD24的烷烃单加氧酶活性最高。在菌株N3A7、MK7、DFY1、AD11和AD24中观察到相对较高的总体醇脱氢酶、脂肪酶和酯酶活性。因此，有潜力在油藏、原油加工和采收过程中使用这些菌株来控制蜡沉积。它们耐受高温并产生用于长链烃降解的降解酶的能力导致短链烃比例增加，进而提高了油的质量。
