Lazzem Assia, Galai Haykel, 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 Materials, Treatment and Analysis, The National Institute of Research and Physico-Chemical Analysis of Sidi-Thabet LMTA, 2020, Sidi Thabet, Tunisia.
Appl Biochem Biotechnol. 2025 May 26. doi: 10.1007/s12010-025-05247-8.
Biosurfactants are surface-active biomolecules with emulsifying properties. These versatile compounds have numerous applications across various industries and environmental contexts, including the remediation of areas contaminated by persistent pollutants such as hydrocarbons. This study focuses on the physicochemical characterization of a biosurfactant produced by a newly identified chrysene-degrading Achromobacter aegrifaciens strain. Biosurfactant production was evaluated using the emulsification index (E24). The research determined the biosurfactant's surface tension, critical micelle concentration (CMC), and stability under different temperatures, pH levels, and salt concentrations. The chemical components of the partially purified biosurfactant were analyzed using biochemical tests, thin layer chromatography (TLC), Fourier transform infrared (FTIR), nuclear magnetic resonance (HNMR) spectroscopy, and gas chromatography-mass spectrometry (GC-MS). After 96 h of incubation, A. aegrifaciens S5 yielded 1.68 g/L of biosurfactant, with a CMC of 50 mg/L. The isolated compound was identified as a novel glycolipopeptide biosurfactant, demonstrating high efficiency with an E24 of 88.4% and the ability to reduce the surface tension of water from 70.3 to 38 mN/m. The biosurfactant exhibited functional stability across temperatures from 4-80 °C, pH levels from 2 to 12, and salt concentrations of 1-10% while maintaining structural integrity up to 120 °C. Given these characteristics, the biosurfactant shows a promising potential for applications in petroleum, detergent, and food industries.
生物表面活性剂是具有乳化特性的表面活性生物分子。这些多功能化合物在各个行业和环境背景中有众多应用，包括修复受碳氢化合物等持久性污染物污染的区域。本研究聚焦于一种新鉴定的降解芘的食酸无色杆菌菌株产生的生物表面活性剂的物理化学特性。使用乳化指数（E24）评估生物表面活性剂的产量。该研究测定了生物表面活性剂的表面张力、临界胶束浓度（CMC）以及在不同温度、pH值和盐浓度下的稳定性。使用生化试验、薄层色谱（TLC）、傅里叶变换红外（FTIR）、核磁共振（HNMR）光谱和气相色谱 - 质谱（GC - MS）分析部分纯化的生物表面活性剂的化学成分。培养96小时后，食酸无色杆菌S5产生了1.68 g/L的生物表面活性剂，CMC为50 mg/L。分离出的化合物被鉴定为一种新型糖脂肽生物表面活性剂，其E24为88.4%，具有高效率，并且能够将水的表面张力从70.3 mN/m降低到38 mN/m。该生物表面活性剂在4至80°C的温度、2至12的pH值以及1至10%的盐浓度范围内表现出功能稳定性，在高达120°C时仍保持结构完整性。鉴于这些特性，该生物表面活性剂在石油、洗涤剂和食品工业中的应用显示出有前景的潜力。
