Lazzem Assia, Lekired Abdelmalek, Ouzari Hadda-Imene, Landoulsi Ahmed, Chatti Abdelwaheb, El May Alya
Laboratory of Risks Related to Environmental Stresses: Fight and Prevention, Faculty of Sciences of Bizerte, University of Carthage, 7021, Jarzouna, Tunisia.
Laboratory of Microorganisms and Actives Biomolecules, Faculty of Sciences of Tunis, University Tunis El Manar, 2092, Tunis, Tunisia.
Int Microbiol. 2024 Jun;27(3):857-869. doi: 10.1007/s10123-023-00435-0. Epub 2023 Oct 18.
Polycyclic aromatic hydrocarbons (PAHs) are considered substances of potential human health hazards because of their resistance to biodegradation and carcinogenic index. Chrysene is a PAH with a high molecular weight (HMW) that poses challenges for its elimination from the environment. However, bacterial degradation is an effective, environmentally friendly, and cost-effective solution. In our study, we isolated a potential chrysene-degrading bacteria from crude oil-contaminated seawater (Bizerte, Tunisia). Based on 16SrRNA analysis, the isolate S5 was identified as Achromobacter aegrifaciens. Furthermore, the results revealed that A. aegrifaciens S5 produced a biofilm on polystyrene at 20 °C and 30 °C, as well as at the air-liquid (A-L) interface. Moreover, this isolate was able to swim and produce biosurfactants with an emulsification activity (E24%) over 53%. Chrysene biodegradation by isolate S5 was clearly assessed by an increase in the total viable count. Confirmation was obtained via gas chromatography-mass spectrometry (GC-MS) analyses. A. aegrifaciens S5 could use chrysene as its sole carbon and energy source, exhibiting an 86% degradation of chrysene on day 7. In addition, the bacterial counts reached their highest level, over 25 × 10 CFU/mL, under the conditions of pH 7.0, a temperature of 30 °C, and a rotary speed of 120 rpm. Based on our findings, A. aegrifaciens S5 can be a potential candidate for bioremediation in HMW-PAH-contaminated environments.
多环芳烃（PAHs）因其抗生物降解性和致癌指数而被认为是对人类健康有潜在危害的物质。屈是一种高分子量（HMW）的多环芳烃，从环境中消除它具有挑战性。然而，细菌降解是一种有效、环保且经济高效的解决方案。在我们的研究中，我们从原油污染的海水中（突尼斯比塞大）分离出一种潜在的屈降解细菌。基于16SrRNA分析，分离株S5被鉴定为嗜铁无色杆菌。此外，结果表明嗜铁无色杆菌S5在20℃和30℃以及气液（A-L）界面处的聚苯乙烯上产生生物膜。此外，该分离株能够游动并产生乳化活性（E24%）超过53%的生物表面活性剂。通过总活菌数的增加清楚地评估了分离株S5对屈的生物降解。通过气相色谱-质谱（GC-MS）分析获得了证实。嗜铁无色杆菌S5可以利用屈作为其唯一的碳源和能源，在第7天表现出86%的屈降解率。此外，在pH 7.0、温度30℃和转速120 rpm的条件下，细菌数量达到最高水平，超过25×10 CFU/mL。基于我们的研究结果，嗜铁无色杆菌S5可能是高分子量多环芳烃污染环境生物修复的潜在候选者。
