Derguine-Mecheri Louiza, Kebbouche-Gana Salima, Djenane Djamel
Laboratory of Food Quality and Food Safety. Mouloud, MAMMERI University, P.O. Box 17, 15000, Tizi-Ouzou, Algeria.
Laboratoire de Conservation et Valorisation des Ressources Biologiques, Université M'Hamed Bougara de Boumerdès, Boumerdès, Algeria.
World J Microbiol Biotechnol. 2021 Jan 4;37(1):18. doi: 10.1007/s11274-020-02983-3.
One of the very promising methods in the field of bioremediation of hydrocarbons is the application of biosurfactant- producing microorganisms based on the use of wastewater as renewable substrates of culture media, contributing to the reduction of costs. With this aim, the production, characterization and properties of the yeast strain YBR producing a biosurfactant newly isolated from an oilfield in Algeria, using wastewater from olive oil mills (OOMW) as a substrate for a low-cost and effective production, have been investigated. Screening of biosurfactant production was carried out with different tests, including emulsification index test (E24), drop collapse test, oil spreading technique and measurement of surface tension (ST). The isolated yeast strain was found to be a potent biosurfactant producer with E24 = 69% and a significant reduction in ST from 72 to 35 mN m. The study of the cultural, biochemical, physiological and genetic characteristics of the isolate allowed us to identify it as Rhodotorula sp. strain YBR. Fermentation was carried out in a 2.5 L Minifors Bioreactor using crude OOMW as culture medium, the E value reached 90% and a reduction of 72 to 35 mN m in ST. A biosurfactant yield = 10.08 ± 0.38 g L was recorded. The characterization by semi-purification and thin layer chromatography (TLC) of the crude extract of biosurfactant showed the presence of peptides, carbohydrates and lipids in its structure. The crude biosurfactant exhibited interesting properties such as: low critical micellar concentration (CMC), significant reduction in ST and strong emulsifying activity. In addition, it has shown stability over a wide range of pH (2-12), temperature (4-100 °C) and salinity (1-10%). More interestingly, the produced biosurfactant has proven to be of great potential application in the remobilization of hydrocarbons from polluted soil with a removal rate of greater than 95%.
在烃类生物修复领域，非常有前景的方法之一是应用能产生生物表面活性剂的微生物，该方法基于使用废水作为培养基的可再生底物，有助于降低成本。为此，对从阿尔及利亚一个油田新分离出的产生物表面活性剂的酵母菌株YBR进行了研究，该菌株以橄榄油厂废水（OOMW）为底物进行低成本高效生产，研究内容包括其生物表面活性剂的生产、表征及特性。通过不同测试进行生物表面活性剂生产的筛选，包括乳化指数测试（E24）、液滴坍塌测试、油扩散技术和表面张力（ST）测量。发现分离出的酵母菌株是一种高效的生物表面活性剂生产者，E24 = 69%，ST从72显著降低到35 mN/m。对该分离株的培养、生化、生理和遗传特性的研究使我们将其鉴定为红酵母属菌株YBR。使用粗制OOMW作为培养基在2.5 L Minifors生物反应器中进行发酵，E值达到90%，ST从72降低到35 mN/m。记录的生物表面活性剂产量为10.08±0.38 g/L。通过对生物表面活性剂粗提物进行半纯化和薄层色谱（TLC）表征，结果表明其结构中存在肽、碳水化合物和脂质。粗制生物表面活性剂表现出有趣的特性，如：低临界胶束浓度（CMC）、ST显著降低和强乳化活性。此外，它在很宽的pH范围（2 - 12）、温度范围（4 - 100°C）和盐度范围（1 - 10%）内都具有稳定性。更有趣的是，所产生的生物表面活性剂已被证明在从污染土壤中去除烃类方面具有巨大的潜在应用价值，去除率大于95%。
