Bioremediation has been proposed as a means of dealing with oil spills on the continent. However, the introduction of non-native organisms, including microbes, even for this purpose would appear to breach the terms of the Environmental Protocol to the Antarctic Treaty. This study therefore aimed to optimize the growth conditions and diesel degradation activity of the Antarctic native bacteria Arthrobacter spp. strains AQ5-05 and AQ5-06 through the application of a one-factor-at-a-time (OFAT) approach. Both strains were psychrotolerant, with the optimum temperature supporting diesel degradation being 10–15°C. Both strains were also screened for biosurfactant production and biofilm formation. Their diesel degradation potential was assessed using Bushnell–Haas medium supplemented with 0.5% (v/v) diesel as the sole carbon source and determined using both gravimetric and gas chromatography and mass spectrophotometry analysis. Strain AQ5-06 achieved 37.5% diesel degradation, while strain AQ5-05 achieved 34.5% diesel degradation. Both strains produced biosurfactants and showed high biofilm adherence. Strains AQ5-05 and AQ5-06 showed high cellular hydrophobicity rates of 73.0% and 81.5%, respectively, in hexadecane, with somewhat lower values of 60.5% and 70.5%, respectively, in tetrahexadecane. Optimized conditions identified via OFAT increased diesel degradation to 41.0% and 47.5% for strains AQ5-05 and AQ5-06, respectively. Both strains also demonstrated the ability to degrade diesel in the presence of heavy metal co-pollutants. This study therefore confirms the potential use of these cold-tolerant bacterial strains in the biodegradation of diesel-polluted Antarctic soils at low environmental temperatures.

中文翻译：

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节杆菌属的冷适应菌株对柴油的生物降解。来自南极洲

生物修复已被提议作为处理非洲大陆石油泄漏的一种手段。然而，即使为此目的引入包括微生物在内的非本土生物似乎也违反了《南极条约环境议定书》的条款。因此，本研究旨在优化南极原生细菌的生长条件和柴油降解活性节杆菌spp. 菌株 AQ5-05 和 AQ5-06 通过应用一次一个因素 (OFAT) 方法。两种菌株都具有耐寒性，支持柴油降解的最佳温度为 10-15°C。还筛选了两种菌株的生物表面活性剂产生和生物膜形成。使用补充 0.5% (v/v) 柴油作为唯一碳源的 Bushnell-Haas 介质评估它们的柴油降解潜力，并使用重量分析和气相色谱以及质谱分析确定。菌株 AQ5-06 实现了 37.5% 的柴油降解，而菌株 AQ5-05 实现了 34.5% 的柴油降解。两种菌株都产生生物表面活性剂并显示出高生物膜粘附性。菌株 AQ5-05 和 AQ5-06 在十六烷中分别表现出 73.0% 和 81.5% 的高细胞疏水率，其值略低，为 60。在十四烷中分别为 5% 和 70.5%。通过 OFAT 确定的优化条件将 AQ5-05 和 AQ5-06 菌株的柴油降解率分别提高到 41.0% 和 47.5%。这两种菌株还表现出在重金属共污染物存在的情况下降解柴油的能力。因此，这项研究证实了这些耐寒细菌菌株在低温环境下柴油污染的南极土壤生物降解中的潜在用途。