title: [Biocatalyst of redox mediators on the denitrification by Paracoccus versutus strain GW1].
abstract: The quinone respiration process of Paracoccus versutus strain GW1 was characterized and the effects of the four redox mediators on the denitrification process were studied. The experiment results suggested that quinones were utilized by Paracoccus versutus strain GW1 as electron acceptors in the respiratory chain and reduced to hydroquinone. Batch experiments were carried out to investigate the biocatalyst effect of redox mediators as catalyst on the denitrification process at 35 degrees C. All four redox mediators tested were able to enhance the nitrate removal efficiency and the denitrification efficiency by 1.14-1.63 fold and 1.12-2.02 fold, respectively. The accelerating effect from high to low was AQDS > 1,5-AQDS > AQS > alpha-AQS. In the presence of redox mediators, the stabilized ORP values in the nitrate decomposition process were reduced by 33-75 mV. The pH variations in denitrification with redox mediators showed similar tendency to that of the conventional nitrate removal process. In the concentration range of 0-0.32 mmol x L(-1), AQDS had the best accelerating effect and a linear correlation was found for the denitrification rate K and the AQDS concentration cAQDS. This study indicated that the application of redox mediators significantly improved the denitrification process by enhancing the decomposition rate.
authors.affiliation: School of Environmental Science and Engineering, Hebei University of Science and Technology, Shijiazhuang 050018, China. LHB19850725@163.com
authors.forename: Hai-Bo
authors.initials: HB
authors.lastname: Li
authors.forename: Jing
authors.initials: J
authors.lastname: Lian
authors.forename: Yan-Kai
authors.initials: YK
authors.lastname: Guo
authors.forename: Li-Jun
authors.initials: LJ
authors.lastname: Zhao
authors.forename: Hai-Feng
authors.initials: HF
authors.lastname: Du
authors.forename: Jing-Liang
authors.initials: JL
authors.lastname: Yang
authors.forename: Jian-Bo
authors.initials: JB
authors.lastname: Guo
mesh_terms: D016227:Benzoquinones / Q000737:chemistry / Q000378:metabolism; D055162:Biocatalysis; D001673:Biodegradation, Environmental; D058440:Denitrification; D009566:Nitrates / Q000302:isolation & purification* / Q000378:metabolism; D010084:Oxidation-Reduction; D010230:Paracoccus / Q000145:classification / Q000378:metabolism*; D014874:Water Pollutants, Chemical / Q000302:isolation & purification* / Q000378:metabolism
chemical_list: D016227:Benzoquinones; D009566:Nitrates; D014874:Water Pollutants, Chemical; C004532:quinone