Biodegradation is a cost-effective process commonly used to eliminate many xenobiotic hydrocarbons such as diesel oils. However, their hydrophobic character reduces the biodegradation efficiency. In order to overcome this hurdle, kurstakins isolated from Bacillus thuringiensis strain 7SA were used as emulsifying agents. The influence of kurstakin molecules on diesel oil degradation by Acinetobacter haemolyticus strain 2SA was evaluated in the presence and absence of the aforementioned lipopeptide. The degradation rates and gene expressions of alkane hydroxylases were evaluated at days 4, 10, 14 and 21. Results showed that kurstakin molecules increased the hydrophobicity of 2SA. Moreover, diesel oil degradation activities were higher in the presence of kurstakin with 29%, 35%, 29% and 23% improvement at 4th, 10th, 14th and 21st day respectively. Statistical analysis indicated that the difference between the degradation rates in the presence and absence of kurstakin was significant with p = 0.03. The detection of three different hydroxylase genes namely alkB, almA and cyp153 in 2SA genome, might have allowed more efficient degradability of alkanes. According to the real-time PCR results, cyp153 was the most induced gene during diesel oil degradation in the presence and absence of kurstakin. Yet, the three genes demonstrated higher levels of expression in the presence of kurstakin when compared to its absence. This study showed that kurstakins enhance the diesel oil biodegradation rate by increasing the hydrophobicity of 2SA. In addition to their anti-fungal activities, kurstakins can be used as biosurfactant to increase biodegradation of diesel oil.

中文翻译：

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Kurstakin 分子通过烷烃羟化酶基因的过表达促进溶血不动杆菌菌株 2SA 对柴油的同化

生物降解是一种经济高效的过程，通常用于消除许多异生烃，如柴油。然而，它们的疏水特性降低了生物降解效率。为了克服这个障碍，从苏云金芽孢杆菌 7SA 菌株中分离出的 kurstakins 被用作乳化剂。在存在和不存在上述脂肽的情况下，评估了 kurstakin 分子对溶血不动杆菌菌株 2SA 对柴油降解的影响。在第 4、10、14 和 21 天评估烷烃羟化酶的降解率和基因表达。结果表明 kurstakin 分子增加了 2SA 的疏水性。此外，在 kurstakin 存在下，柴油降解活性更高，在第 4、10、14 和 21 天分别提高了 29%、35%、29% 和 23%。统计分析表明，存在和不存在 kurstakin 的降解率之间的差异是显着的，p = 0.03。在 2SA 基因组中检测到三种不同的羟化酶基因，即 alkB、almA 和 cyp153，可能允许更有效地降解烷烃。根据实时荧光定量PCR结果，在存在和不存在kurstakin的情况下，cyp153是柴油降解过程中诱导最多的基因。然而，与不存在 kurstakin 相比，这三个基因在存在 kurstakin 的情况下表现出更高的表达水平。该研究表明，kurstakins 通过增加 2SA 的疏水性来提高柴油生物降解率。除了它们的抗真菌活性之外，Kurstakins 还可以用作生物表面活性剂以增加柴油的生物降解。