title: Effect of NaCl on aerobic denitrification by strain Achromobacter sp. GAD-3.
abstract: This paper presents the effect of NaCl on aerobic denitrification by a novel aerobic denitrifier strain Achromobacter sp. GAD-3. Results indicated that the aerobic denitrification process was inhibited by NaCl concentrations ≥20 g L-1, leading to lower nitrate removal rates (1.67∼4.0 mg L-1h-1), higher nitrite accumulation (50.2∼87.4 mg L-1), and increasing N2O emission ratios (13∼72 mg L-1/mg L-1). Poor performance of aerobic denitrification at high salinity was attributed to the suppression of active microbial biomass and electron donating capacity of strain GAD-3. Further studies on the corresponding inhibition of the denitrifying gene expression by higher salinities revealed the significant sensitivity order of nosZ (for N2O reductase) > cnorB (for NO reductase) ≈ nirS (for cytochrome cd(1) nitrite reductase) > napA (for periplasmic nitrate reductase), accompanied with a time-lapse expression between nosZ and cnorB based on reverse transcription and real-time quantitative polymerase chain reaction (RT-qPCR) analysis. The insights into the effect of NaCl on aerobic denitrification are of great significance to upgrade wastewater treatment plants (WWTPs) containing varying levels of salinity.
authors.affiliation: Department of Environmental Engineering, Key Laboratory of Water and Sediment Sciences, Ministry of Education, Peking University, Beijing, 100871, China.
authors.forename: Mengyao
authors.initials: M
authors.lastname: Gui
authors.affiliation: Department of Environmental Engineering, Key Laboratory of Water and Sediment Sciences, Ministry of Education, Peking University, Beijing, 100871, China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Chen
authors.affiliation: Department of Environmental Engineering, Key Laboratory of Water and Sediment Sciences, Ministry of Education, Peking University, Beijing, 100871, China. nijinren@iee.pku.edu.cn.
authors.forename: Jinren
authors.initials: J
authors.lastname: Ni
mesh_terms: D042402:Achromobacter / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism*; D000332:Aerobiosis; D018533:Biomass; D058440:Denitrification; D015870:Gene Expression; D050901:Nitrate Reductase / Q000235:genetics / Q000378:metabolism; D009566:Nitrates / Q000378:metabolism*; D009572:Nitrite Reductases / Q000378:metabolism; D009573:Nitrites / Q000378:metabolism*; D010088:Oxidoreductases / Q000235:genetics / Q000378:metabolism; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D054712:Salinity; D012965:Sodium Chloride / Q000494:pharmacology*; D062065:Wastewater / Q000382:microbiology
chemical_list: D050901:Nitrate Reductase; D009566:Nitrates; D009572:Nitrite Reductases; D009573:Nitrites; D010088:Oxidoreductases; D012336:RNA, Ribosomal, 16S; D012965:Sodium Chloride; D062065:Wastewater; C022763:nitrous oxide reductase; C034747:nitric-oxide reductase
keywords: Achromobacter sp.; Aerobic denitrification; ETSA; Gene expression; NaCl; Sensitivity