The oxidative stress response represents a sum of antioxidative mechanisms that are essential for determining the adaptation and abundance of microorganisms in the environment. Leptospirillum ferriphilum and Acidithiobacillus ferrooxidans are chemolithotrophic bacteria that obtain their energy from the oxidation of ferrous ion. Both microorganisms are important for bioleaching of sulfidic ores and both are tolerant to high levels of heavy metals and other factors that can induce oxidative stress. In this work, we compared the tolerance and response of L. ferriphilum and At. ferrooxidans to Fe³⁺, H₂O₂, K₂CrO₄, and UV-C radiation. We evaluated growth, generation of reactive oxygen species (ROS), oxidative damage to lipid membranes and DNA, and the activity of antioxidative proteins in cells exposed to these stressors. L. ferriphilum had higher cell density, lower ROS content and less lipid and DNA damage than At. ferrooxidans. Consistent with this, the activity levels of thioredoxin and superoxide dismutase in L. ferriphilum were upregulated and higher than in At. ferrooxidans. This indicated that L. ferriphilum has a higher capacity to respond to oxidative stress and to manage redox homeostasis. This capacity could largely contribute to the high abundance of this species in natural and anthropogenic sites.

氧化应激反应代表了抗氧化机制的总和，这些机制对于确定环境中微生物的适应性和丰度至关重要。嗜铁钩端螺旋体和氧化亚铁酸硫杆菌是从亚铁离子氧化中获取能量的化学营养型细菌。这两种微生物对于硫化矿的生物浸出都很重要，并且都能耐受高水平的重金属和其他可诱导氧化应激的因素。在这项工作中，我们比较了L. ferriphilum和At的耐受性和响应。氧化亚铁至 Fe ³⁺ , H ₂ O ₂ , K ₂ CrO ₄, 和 UV-C 辐射。我们评估了生长、活性氧 (ROS) 的产生、脂质膜和 DNA 的氧化损伤，以及暴露于这些压力源的细胞中抗氧化蛋白的活性。L. ferriphilum比At具有更高的细胞密度、更低的 ROS 含量和更少的脂质和 DNA 损伤。氧化亚铁。与此一致，L. ferriphilum中硫氧还蛋白和超氧化物歧化酶的活性水平上调并高于At。氧化亚铁。这表明L. ferriphilum具有更高的能力来响应氧化应激和管理氧化还原稳态。这种能力在很大程度上有助于该物种在自然和人为地点的高丰度。