title: Effects of quinoid redox mediators on the activity of anammox biomass.
abstract: This study first explored the relationship between the activity of anammox biomass/key enzymes and quinoid redox mediators, which were anthraquinone-2,6-disulfonate (AQDS), 2-hydroxy-1,4-napthoquinone (LAW) and anthraquinone-2-carboxylic acid (AQC). Experimental results demonstrated that the total nitrogen removal performance showed a downward trend with all three redox mediators (RMs) dosage increasing. For instance, when the AQC addition increased to 0.8 mM, the TN removal rate sharply reduced to 17.2 mg-N/gVSS/h, only about 20% of the control. This phenomenon might be caused by microbial poisoning with the extracellular RMs additions. Nevertheless, the crude hydrazine dehydrogenase, nitrite reductase, and nitrate reductase activities were enhanced with RMs addition, about 0.6-3 folds compared to the control experiments without RMs addition. The RMs was inferred to play the role as ubiquinol/ubiquinone (Q/QH2) during the anammox process. Furthermore, the specific ladderane membrane structure could block the contacting between RMs and the key enzymes inside anammoxosome. This might be the main reason for the contrary effects of RMs on anammox biomass and the key enzymes.
authors.affiliation: Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education, China), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, PR China. Electronic address: qscyj@mail.dlut.edu.cn.
authors.forename: Sen
authors.initials: S
authors.lastname: Qiao
authors.affiliation: Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education, China), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, PR China.
authors.forename: Tian
authors.initials: T
authors.lastname: Tian
authors.affiliation: Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education, China), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, PR China.
authors.forename: Jiti
authors.initials: J
authors.lastname: Zhou
mesh_terms: D000641:Ammonia / Q000378:metabolism*; D000693:Anaerobiosis / Q000187:drug effects; D001419:Bacteria / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D018533:Biomass; D053858:Metabolic Networks and Pathways / Q000187:drug effects; D050901:Nitrate Reductase / Q000378:metabolism; D009572:Nitrite Reductases / Q000378:metabolism; D010084:Oxidation-Reduction / Q000187:drug effects; D010088:Oxidoreductases / Q000378:metabolism; D011809:Quinones / Q000494:pharmacology*
chemical_list: D011809:Quinones; D000641:Ammonia; D010088:Oxidoreductases; D009572:Nitrite Reductases; D050901:Nitrate Reductase
keywords: Anammox; Hydrazine dehydrogenase; Nitrate reductase; Nitrite reductase; Redox mediator