Key Laboratory of Functional Dairy Science of Chinese Ministry of Education and Municipal Government of Beijing, and Beijing Higher Institution Engineering Research Center of Animal Product, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, PR China.
College of Agriculture and Biotechnology, China Agricultural University, Beijing 100193, PR China.
Microbiology (Reading). 2011 Jun;157(Pt 6):1573-1588. doi: 10.1099/mic.0.044297-0. Epub 2011 Feb 24.
Bifidobacterium longum subsp. longum BBMN68, an anaerobic probiotic isolated from healthy centenarian faeces, shows low oxygen (3 %, v/v) tolerance. To understand the effects of oxidative stress and the mechanisms protecting against it in this strain, a proteomic approach was taken to analyse changes in the cellular protein profiles of BBMN68 under the following oxygen-stress conditions. Mid-exponential phase BBMN68 cells grown in MRS broth at 37 °C were exposed to 3 % O(2) for 1 h (I) or 9 h (II), and stationary phase cells were subjected to 3 % O(2) for 1 h (III). Respective controls were grown under identical conditions but were not exposed to O(2). A total of 51 spots with significant changes after exposure to oxygen were identified, including the oxidative stress-protective proteins alkyl hydroperoxide reductase C22 (AhpC) and pyridine nucleotide-disulfide reductase (PNDR), and the DNA oxidative damage-protective proteins DNA-binding ferritin-like protein (Dps), ribonucleotide reductase (NrdA) and nucleotide triphosphate (NTP) pyrophosphohydrolases (MutT1). Changes in polynucleotide phosphorylase (PNPase) plus enolase, which may play important roles in scavenging oxidatively damaged RNA, were also found. Following validation at the transcriptional level of differentially expressed proteins, the physiological and biochemical functions of BBMN68 Dps were further proven by in vitro and in vivo tests under oxidative stress. Our results reveal the key oxidative stress-protective proteins and DNA oxidative damage-protective proteins involved in the defence strategy of BBMN68 against oxygen, and provide the first proteomic information toward understanding the responses of Bifidobacterium and other anaerobes to oxygen stress.
长双歧杆菌亚种。长双歧杆菌 BBMN68 是一种从健康百岁老人粪便中分离出来的厌氧益生菌，对低氧（3%，v/v）有耐受性。为了了解该菌株在氧化应激下的影响和保护机制，采用蛋白质组学方法分析了 BBMN68 在以下氧应激条件下细胞蛋白图谱的变化。在 37°C 的 MRS 肉汤中培养的指数生长期 BBMN68 细胞暴露于 3% O(2) 1 小时（I）或 9 小时（II），并对静止期细胞进行 3% O(2) 1 小时（III）处理。相应的对照在相同条件下生长，但不暴露于 O(2)。共鉴定出 51 个在暴露于氧气后发生显著变化的斑点，包括氧化应激保护蛋白烷基氢过氧化物还原酶 C22（AhpC）和吡啶核苷酸二硫化物还原酶（PNDR），以及 DNA 氧化损伤保护蛋白 DNA 结合铁蛋白样蛋白（Dps）、核糖核苷酸还原酶（NrdA）和核苷酸三磷酸（NTP）焦磷酸水解酶（MutT1）。还发现多核苷酸磷酸化酶（PNPase）加烯醇酶的变化，它们可能在清除氧化损伤的 RNA 方面发挥重要作用。在差异表达蛋白的转录水平验证后，进一步通过体外和体内试验证明了 BBMN68 Dps 在氧化应激下的生理和生化功能。我们的研究结果揭示了 BBMN68 抵抗氧的关键氧化应激保护蛋白和 DNA 氧化损伤保护蛋白，并为理解双歧杆菌和其他厌氧菌对氧应激的反应提供了第一个蛋白质组学信息。
