Purpose

Despite wide research on bioremediation of hydrocarbon-contaminated soil, the mechanisms of surfactant-enhanced bioavailability of the contaminants are still unclear. The presented study was focused on the in-depth description of relationships between hydrocarbons, bacteria, and surfactants. In order to that, the biodegradation experiments and cell viability measurements were conducted, and the properties of cell surface were characterized.

Methods

MTT assay was employed to measure plant extracts toxicity to microbes. Then, membrane permeability changes were evaluated, followed by diesel oil biodegradation in the presence of surfactants measurements by GCxGC-TOFMS and PCR-RAPD analysis.

Results

Our study undoubtedly proves that different surfactants promote assimilation of different groups of hydrocarbons and modify cell surface properties in different ways. Increased biodegradation of diesel oil was observed when cultures with Acinetobacter calcoaceticus M1B were supplemented with Saponaria officinalis and Verbascum nigrum extracts. Interestingly, these surfactants exhibit different influences on cell surface properties and their viability in contrast to the other surfactants. Moreover, the preliminary analyses have shown changes in the genome caused by exposure to surfactants.

Conclusions

The results indicated that the benefits of surfactant use may be related to deep modification at the omics level, not only that of cell surface properties and confirms the complexity of the interactions between bacterial cells, pollutants and surfactants.

中文翻译：

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在柴油降解中添加表面活性剂——它如何帮助微生物？

目的

尽管对碳氢化合物污染土壤的生物修复进行了广泛的研究，但表面活性剂增强污染物生物利用度的机制仍不清楚。所提出的研究重点是深入描述碳氢化合物、细菌和表面活性剂之间的关系。为此，进行了生物降解实验和细胞活力测量，并对细胞表面的特性进行了表征。

方法

MTT法用于测量植物提取物对微生物的毒性。然后，评估膜渗透性变化，然后通过 GCxGC-TOFMS 和 PCR-RAPD 分析在表面活性剂存在下进行柴油生物降解。

结果

我们的研究无疑证明了不同的表面活性剂促进不同组烃的同化并以不同的方式改变细胞表面性质。当用醋酸钙不动杆菌M1B 培养物补充皂草和毛蕊花提取物时，观察到柴油的生物降解增加。有趣的是，与其他表面活性剂相比，这些表面活性剂对细胞表面性质及其活力表现出不同的影响。此外，初步分析表明，暴露于表面活性剂会导致基因组发生变化。

结论

结果表明，使用表面活性剂的好处可能与组学水平的深度修饰有关，而不仅仅是细胞表面性质的修饰，并证实了细菌细胞、污染物和表面活性剂之间相互作用的复杂性。