Abstract An Achromobacter species strain AC15 was isolated from mangrove soil and identified as a potent producer of biosurfactant. It could utilize high concentrations of pyrene as the sole source of carbon and energy. Results showed that AC15 degraded about 40% of the pyrene, which was provided at an initial concentration of 300 mg L−1, and reduced surface tension of the culture medium from 67.2 to 33.2 mN m−1 after 14 d of incubation using its good emulsification property on the culture medium. The main chemical component of partially purified biosurfactant, namely BS15, was analyzed by gas chromatography-mass spectrometry, amino acid analysis, and LTQ Orbitrap Elite mass spectrometry. Results showed that BS15 was a novel linear lipopeptide with a long-chain C16 fatty acid and peptide comprised of four amino acid residues. The molecular structure was determined as CH3-(CH2)14–CO–O-Leu-Asp-Lys-Ser. The solubility of pyrene in water improved 1.5–1.9 times in the presence of 40–60 mg L−1 of BS15. This work demonstrated that strain AC15 and its biosurfactant BS15 could be potential candidates in further applications of bioremediation of high-molecular weight polycyclic aromatic hydrocarbons.

中文翻译：

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由有效降解芘的无色杆菌属菌株 AC15 产生的新型生物表面活性剂的表征

摘要 从红树林土壤中分离出一株无色杆菌菌株AC15，并被鉴定为一种有效的生物表面活性剂生产者。它可以利用高浓度的芘作为碳和能源的唯一来源。结果表明，AC15 在初始浓度为 300 mg L-1 时降解了约 40% 的芘，并在使用其良好的孵育 14 天后将培养基的表面张力从 67.2 mN m-1 降低到 33.2 mN m-1。对培养基的乳化特性。部分纯化的生物表面活性剂的主要化学成分 BS15 通过气相色谱-质谱、氨基酸分析和 LTQ Orbitrap Elite 质谱进行分析。结果表明，BS15 是一种新型线性脂肽，具有长链 C16 脂肪酸和由四个氨基酸残基组成的肽。分子结构确定为 CH3-(CH2)14-CO-O-Leu-Asp-Lys-Ser。在 40-60 mg L-1 BS15 存在下芘在水中的溶解度提高了 1.5-1.9 倍。这项工作表明菌株 AC15 及其生物表面活性剂 BS15 可能是高分子量多环芳烃生物修复进一步应用的潜在候选者。