Colonnella María Antonela, Lizarraga Leonardo, Rossi Leticia, Díaz Peña Rocío, Egoburo Diego, López Nancy I, Iustman Laura J Raiger
CIBION, CONICET, Buenos Aires, Argentina.
Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Intendente Guiraldes, 2160, C1428EGA, Buenos Aires, Argentina.
Extremophiles. 2019 Jan;23(1):91-99. doi: 10.1007/s00792-018-1063-2. Epub 2018 Oct 17.
Environments co-contaminated with heavy metals and hydrocarbons have become an important problem worldwide, especially due to the effect of metals on hydrocarbon degrading microorganisms. Pseudomonas extremaustralis, a bacterium isolated from a pristine pond in Antarctica, showed high capabilities to cope with environmental stress and a very versatile metabolism that includes alkane degradation under microaerobic conditions. In this work, we analyzed P. extremaustralis' capability to resist high copper concentrations and the effect of copper presence in diesel biodegradation. We observed that P. extremaustralis resisted up to 4 mM CuSO in a rich medium such as LB. This copper resistance is sustained by the presence of the cus and cop operons together with other efflux systems and porins located in a single region in P. extremaustralis genome. When copper was present, diesel degradation was negatively affected, even though copper enhanced bacterial attachment to hydrocarbons. However, when a small amount of glucose (0.05% w/v) was added, the presence of CuSO enhanced alkane degradation. In addition, atomic force microscopy analysis showed that the presence of glucose decreased the negative effects produced by copper and diesel on the cell envelopes.
重金属和碳氢化合物共同污染的环境已成为全球一个重要问题，尤其是因为金属对碳氢化合物降解微生物的影响。南极极端假单胞菌是从南极洲一个原始池塘分离出的一种细菌，它表现出应对环境压力的高能力以及非常多样的新陈代谢，包括在微需氧条件下的烷烃降解。在这项工作中，我们分析了南极极端假单胞菌抵抗高浓度铜的能力以及铜的存在对柴油生物降解的影响。我们观察到，在诸如LB这样的丰富培养基中，南极极端假单胞菌能抵抗高达4 mM的硫酸铜。这种铜抗性由cus和cop操纵子以及位于南极极端假单胞菌基因组单个区域的其他外排系统和孔蛋白共同维持。当有铜存在时，柴油降解受到负面影响，尽管铜增强了细菌对碳氢化合物的附着。然而，当添加少量葡萄糖（0.05% w/v）时，硫酸铜的存在增强了烷烃降解。此外，原子力显微镜分析表明，葡萄糖的存在减少了铜和柴油对细胞膜产生的负面影响。
