Bioremediation is one of the promising environment-friendly approaches to eliminate oil contamination. However, heavy oil is known to degrade slowly due to its hydrophobicity. Therefore, microorganisms capable of producing biosurfactants are gaining substantial interest because of their potential to alter hydrocarbon properties and thereby speed up the degradation process. In this study, six bacterial consortia were obtained from the oil-spilled beach areas in Miyagi, Japan, and all of which exhibited high potential in degrading heavy oil measured by gas chromatography with flame ionization detector (GC-FID). The polymerase chain reaction—denaturing gradient gel electrophoresis (PCR-DGGE) and next-generation sequencing (NGS) revealed that the diverse microbial community in each consortium changed with subculture and became stable with a few effective microorganisms after 15 generations. The total petroleum hydrocarbons (TPH) degradation ability of the consortia obtained from a former gas station (C1: 81%) and oil refinery company (C6: 79%) was higher than that of the consortia obtained from wastewater treatment plant (WWTP) (C3: 67%, and C5: 73%), indicating that bacteria present in C1 and C6 were historically exposed to petroleum hydrocarbons. Moreover, it was intriguing that the consortium C4, also obtained from WWTP, exhibited high TPH degradation ability (77%). The NGS results revealed that two bacteria, Achromobacter sp. and Ochrobactrum sp., occupied more than 99% of the consortium C4, while no Pseudomonas sp. was found in C4, though this bacterium was observed in other consortia and is also known to be a potential candidate for TPH degradation as reported by previous studies. In addition, the consortium C4 showed high biosurfactant-producing ability among the studied consortia. To date, no study has reported the TPH degradation by the combination of Achromobacter sp. and Ochrobactrum sp.; therefore, the consortium C4 provided an excellent opportunity to study the interaction of and biosurfactant production by these two bacteria during TPH degradation.

中文翻译：

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从日本宫城县海啸造成的溢油海滩地区获得的细菌财团生产生物表面活性剂对降解重油的潜力

生物修复是消除油污的有前途的环境友好方法之一。然而，已知重油由于其疏水性而缓慢降解。因此，能够产生生物表面活性剂的微生物由于具有改变碳氢化合物性质并由此加速降解过程的潜力而受到广泛关注。在这项研究中，从日本宫城县的溢油海滩地区获得了六个细菌聚生体，它们均具有通过火焰离子化检测器（GC-FID）气相色谱法测定的重油降解潜力。聚合酶链反应-变性梯度凝胶电泳（PCR-DGGE）和下一代测序（NGS）表明，每个亚群中的不同微生物群落随传代培养而变化，并在15代后对一些有效微生物变得稳定。从前加油站获得的财团（C1：81％）和炼油公司（C6：79％）获得的财团的总石油烃（TPH）降解能力高于从废水处理厂（WWTP）获得的财团的（TPH）（ C3：67％，C5：73％），这表明C1和C6中存在的细菌历来是接触石油烃的。此外，同样有趣的是，同样从WWTP获得的财团C4表现出高的TPH降解能力（77％）。NGS结果显示，两种细菌 从前加油站获得的财团（C1：81％）和炼油公司（C6：79％）获得的财团的总石油烃（TPH）降解能力高于从废水处理厂（WWTP）获得的财团的（TPH）（ C3：67％，C5：73％），这表明C1和C6中存在的细菌历来是接触石油烃的。此外，同样有趣的是，同样从WWTP获得的财团C4表现出高的TPH降解能力（77％）。NGS结果表明，两种细菌 从前加油站获得的财团（C1：81％）和炼油公司（C6：79％）获得的财团的总石油烃（TPH）降解能力高于从废水处理厂（WWTP）获得的财团的（TPH）（ C3：67％，C5：73％），这表明C1和C6中存在的细菌历来是接触石油烃的。此外，同样有趣的是，同样从WWTP获得的财团C4表现出高的TPH降解能力（77％）。NGS结果表明，两种细菌 这表明历史上C1和C6中存在细菌。此外，同样有趣的是，同样从WWTP获得的财团C4表现出高的TPH降解能力（77％）。NGS结果表明，两种细菌 这表明历史上C1和C6中存在细菌。此外，同样有趣的是，同样从WWTP获得的财团C4表现出高的TPH降解能力（77％）。NGS结果表明，两种细菌无色SP。和O鼠属（Ochrobactrum sp。）占据了C4财团的99％以上，而假单胞菌（Pseudomonas sp。）在C4中发现了这种细菌，尽管该细菌在其他财团中也观察到，并且如先前研究报道的那样，也已知是TPH降解的潜在候选者。另外，在研究的财团中，财团C4显示出高的生物表面活性剂生产能力。迄今为止，尚无研究报道无色杆菌属组合的TPH降解。和Ochrobactrum sp .；因此，财团C4提供了一个极好的机会来研究TPH降解过程中这两种细菌的​​相互作用和生物表面活性剂的产生。