title: Homologous overexpression of alkyl hydroperoxide reductase subunit C (ahpC) protects Bifidobacterium longum strain NCC2705 from oxidative stress.
abstract: The ability to manage reactive oxygen species (ROS) effectively is crucial for the survival of gut bifidobacteria under conditions of oxidative stress. Alkyl hydroperoxide reductase catalytic subunit C (ahpC) of Bifidobacterium longum responds to various oxidative stresses. In this study, an ahpC-overexpressing transformant of B. longum strain NCC2705 was constructed to investigate the role and function of ahpC in oxidative stresses inflicted by treatments with hydrogen peroxide (H2O2), cumene hydroperoxide, and aerobic oxygen. Results indicated that in B. longum, AhpC is the primary scavenger of endogenous H2O2 generated by aerobic metabolism, but it is unable to detoxify high concentrations of exogenous H2O2. The ahpC-overexpressing B. longum strain showed increased resistance to organic hydroperoxide killing, increased viability under aerobic growth, but decreased resistance to exogenous H2O2 in comparison to the control strain. Analysis of genes from the oxidative stress-defense pathway encoding oxygen-independent coproporphyrinogen III oxidase (HemN), NADH oxidase (Nox) and thioredoxin reductase-like protein (TrxB) showed increased transcript levels in the ahpC-overexpressing vs. control strain. These findings suggest that elevated ahpC expression facilitates or activates the different electron donor-dependent ROS-elimination pathways in B. longum's response to oxidative stress.
authors: Key Laboratory of Functional Dairy Science of Chinese Ministry of Education and Municipal Government of Beijing, Beijing Laboratory for Food Quality and Safety, College of Food Science and Nutritional Engineering, China Agricultural University, No. 17 Qinghua East Road, Haidian District, Beijing 100083, PR China. Electronic address: duruolanzi@gmail.com.
authors: FangLei
authors: F
authors: Zuo
authors: Key Laboratory of Functional Dairy Science of Chinese Ministry of Education and Municipal Government of Beijing, Beijing Laboratory for Food Quality and Safety, College of Food Science and Nutritional Engineering, China Agricultural University, No. 17 Qinghua East Road, Haidian District, Beijing 100083, PR China. Electronic address: hardheartyr@sina.com.
authors: Rui
authors: R
authors: Yu
authors: Key Laboratory of Functional Dairy Science of Chinese Ministry of Education and Municipal Government of Beijing, Beijing Laboratory for Food Quality and Safety, College of Food Science and Nutritional Engineering, China Agricultural University, No. 17 Qinghua East Road, Haidian District, Beijing 100083, PR China. Electronic address: khaskhelig@gmail.com.
authors: Gul Bahar
authors: GB
authors: Khaskheli
authors: College of Agriculture and Biotechnology, China Agricultural University, No. 2 Yuanmingyuan West Road, Haidian District, Beijing 100193, PR China. Electronic address: hqma@cau.edu.cn.
authors: HuiQin
authors: H
authors: Ma
authors: Key Laboratory of Functional Dairy Science of Chinese Ministry of Education and Municipal Government of Beijing, Beijing Laboratory for Food Quality and Safety, College of Food Science and Nutritional Engineering, China Agricultural University, No. 17 Qinghua East Road, Haidian District, Beijing 100083, PR China. Electronic address: itachi.regulus@gmail.com.
authors: LiLi
authors: L
authors: Chen
authors: Key Laboratory of Functional Dairy Science of Chinese Ministry of Education and Municipal Government of Beijing, Beijing Laboratory for Food Quality and Safety, College of Food Science and Nutritional Engineering, China Agricultural University, No. 17 Qinghua East Road, Haidian District, Beijing 100083, PR China. Electronic address: zengzhuydyxf@163.com.
authors: Zhu
authors: Z
authors: Zeng
authors: Beijing Agricultural Function Microbial Engineering and Technology Center, No. 1 Li'ersi Industrial Area, Zhangjiawan Town, Tongzhou District, Beijing 101113, PR China. Electronic address: maoaijun@polo-china.com.
authors: AiJun
authors: A
authors: Mao
authors: Key Laboratory of Functional Dairy Science of Chinese Ministry of Education and Municipal Government of Beijing, Beijing Laboratory for Food Quality and Safety, College of Food Science and Nutritional Engineering, China Agricultural University, No. 17 Qinghua East Road, Haidian District, Beijing 100083, PR China; Beijing Agricultural Function Microbial Engineering and Technology Center, No. 1 Li'ersi Industrial Area, Zhangjiawan Town, Tongzhou District, Beijing 101113, PR China. Electronic address: swchen@cau.edu.cn.
authors: ShangWu
authors: S
authors: Chen
mesh_terms: D001555:Benzene Derivatives / Q000633:toxicity; D001644:Bifidobacterium / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics / Q000502:physiology*; D006861:Hydrogen Peroxide / Q000633:toxicity; D050296:Microbial Viability / Q000187:drug effects; D018384:Oxidative Stress; D010100:Oxygen / Q000633:toxicity; D054464:Peroxiredoxins / Q000096:biosynthesis* / Q000235:genetics; D021122:Protein Subunits / Q000096:biosynthesis / Q000235:genetics; D017382:Reactive Oxygen Species / Q000378:metabolism* / Q000633:toxicity; D013312:Stress, Physiological
chemical_list: D001555:Benzene Derivatives; D021122:Protein Subunits; D017382:Reactive Oxygen Species; D006861:Hydrogen Peroxide; D054464:Peroxiredoxins; C007164:cumene hydroperoxide; D010100:Oxygen
keywords: Alkyl hydroperoxide reductase; Bifidobacterium longum; Oxidative stress