RT Journal Article SR Electronic(1) A1 Xiao, Man A1 Xu, Pan A1 Zhao, Jianyun A1 Wang, Zeng A1 Zuo, Fanglei A1 Zhang, Jiangwei A1 Ren, Fazheng A1 Li, Pinglan A1 Chen, Shangwu A1 Ma, HuiqinYR 2011 T1 Oxidative stress-related responses of Bifidobacterium longum subsp. longum BBMN68 at the proteomic level after exposure to oxygen JF Microbiology, VO 157 IS 6 SP 1573 OP 1588 DO https://doi.org/10.1099/mic.0.044297-0 PB Microbiology Society, SN 1465-2080, AB 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 % O2 for 1 h (I) or 9 h (II), and stationary phase cells were subjected to 3 % O2 for 1 h (III). Respective controls were grown under identical conditions but were not exposed to O2. 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., UL https://www.microbiologyresearch.org/content/journal/micro/10.1099/mic.0.044297-0