title: Microbial community and metabolism activity in a bioelectrochemical denitrification system under long-term presence of p-nitrophenol.
abstract: Bioelectrochemical denitrification system (BEDS) is a promising technology for nitrate removal from wastewaters. The hazards and effects concerning p-nitrophenol (PNP) towards BEDS lack enough investigations and possess great research prospects. This study investigated how PNP affected the nitrate removal efficiency, microbial communities, functional denitrifying genes abundances, nitrate and nitrite reductase activities, diffusible signal factors (DSF) release, and extracellular polymeric substances (EPS) production in the BEDS. Results indicated that nitrate removal efficiency decreased with initial PNP concentration increased from 0 to 100mg/L. Phylum Firmicutes and class Clostridia were the main contributors for denitrification process in this BEDS. The abundances of the denitrifying genes nirS, nirK, napA, and narG all presented decreased trends with increasing PNP. In addition, the concentrations of nitrate reductase (NR), nitrite reductase (NIR), and EPS obviously decreased, while the concentration of DSF increased with increasing PNP, which demonstrated that higher PNP would inhibit the biofilm formation.
authors.affiliation: School of Civil Engineering, Wuhan University, Wuhan 430072, China.
authors.forename: Dan
authors.initials: D
authors.lastname: Chen
authors.affiliation: School of Civil Engineering, Wuhan University, Wuhan 430072, China.
authors.forename: Kai
authors.initials: K
authors.lastname: Yang
authors.affiliation: State Key Lab of Urban Water Resources and Environment, Harbin Institute of Technology, Harbin 150090, China.
authors.forename: Li
authors.initials: L
authors.lastname: Wei
authors.affiliation: School of Civil Engineering, Wuhan University, Wuhan 430072, China. Electronic address: hongyuwangcc@126.com.
authors.forename: Hongyu
authors.initials: H
authors.lastname: Wang
mesh_terms: D018441:Biofilms; D001709:Biotechnology / Q000379:methods*; D003013:Clostridium / Q000378:metabolism; D058440:Denitrification; D004563:Electrochemistry / Q000379:methods; D000068536:Bacillota / Q000378:metabolism; D050901:Nitrate Reductase / Q000737:chemistry / Q000378:metabolism; D009566:Nitrates / Q000737:chemistry* / Q000378:metabolism; D009572:Nitrite Reductases / Q000378:metabolism; D009596:Nitrophenols / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry; D060888:Real-Time Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D013053:Spectrophotometry; D062065:Wastewater
chemical_list: D050901:Nitrate Reductase; D009566:Nitrates; D009572:Nitrite Reductases; D009596:Nitrophenols; D011108:Polymers; D062065:Wastewater; C024836:4-nitrophenol
keywords: Bioelectrochemical; Denitrifying genes; Microbial communities; p-Nitrophenol