title: The role of electron donors generated from UV photolysis for accelerating pyridine biodegradation.
abstract: Employing an internal circulation baffled biofilm reactor (ICBBR), we evaluated the mechanisms by which photolysis accelerated the biodegradation and mineralization of pyridine (C5 H5 N), a nitrogen-containing heterocyclic compound. We tested the hypothesis that pyridine oxidation is accelerated because a key photolysis intermediate, succinate, is as electron donor that promotes the initial mono-oxygenation of pyridine. Experimentally, longer photolysis time generated more electron-donor products (succinate), which stimulated faster pyridine biodegradation. This pattern was confirmed by directly adding succinate, and the stimulation effect occurred similarly with addition of the same equivalents of acetate and formate. Succinate, whether generated by UV photolysis or added directly, also accelerated mono-oxygenation of the first biodegradation intermediate, 2-hydroxyl pyridine (2HP). 2HP and pyridine were mutually inhibitory in that their mono-oxygenations competed for internal electron donor; thus, the addition of any readily biodegradable donor accelerated both mono-oxygenation steps, as well as mineralization.
authors: Department of Environmental Science and Engineering, College of Life and Environmental Science, Shanghai Normal University, Shanghai, 200234, China.
authors: Yingxia
authors: Y
authors: Tang
authors: Department of Environmental Science and Engineering, College of Life and Environmental Science, Shanghai Normal University, Shanghai, 200234, China. zhym@shnu.edu.cn.
authors: Yongming
authors: Y
authors: Zhang
authors: Department of Environmental Science and Engineering, College of Life and Environmental Science, Shanghai Normal University, Shanghai, 200234, China.
authors: Ning
authors: N
authors: Yan
authors: Zhejiang Provincial Key Laboratory of Water Science and Technology, Department of Environmental Technology and Ecology, Yangtze Delta Region Institute of Tsinghua University, Zhejiang, Jiaxing, China.
authors: Rui
authors: R
authors: Liu
authors: Swette Center for Environmental Biotechnology, Biodesign Institute, Arizona State University, Tempe, Arizona.
authors: Bruce E
authors: BE
authors: Rittmann
mesh_terms: D001673:Biodegradation, Environmental; D019149:Bioreactors; D004583:Electrons; D010782:Photolysis; D011725:Pyridines / Q000737:chemistry / Q000378:metabolism; D019802:Succinic Acid / Q000737:chemistry / Q000378:metabolism; D014466:Ultraviolet Rays
chemical_list: D011725:Pyridines; D019802:Succinic Acid; C023666:pyridine
keywords: electron donors; mono-oxygenation reaction; pyridine