title: The fate of a nitrobenzene-degrading bacterium in pharmaceutical wastewater treatment sludge.
abstract: This paper describes the fate of a nitrobenzene-degrading bacterium, Klebsiella oxytoca NBA-1, which was isolated from a pharmaceutical wastewater treatment facility. The 90-day survivability of strain NBA-1 after exposure to sludge under anaerobic and aerobic conditions was investigated. The bacterium was inoculated into sludge amended with glucose and p-chloronitrobenzene (p-CNB) to compare the bacterial community variations between the modified sludge and nitrobenzene amendment. The results showed that glucose had no obvious effect on nitrobenzene biodegradation in the co-metabolism process, regardless of the presence/absence of oxygen. When p-CNB was added under anaerobic conditions, the biodegradation rate of nitrobenzene remained unchanged although p-CNB inhibited the production of aniline. The diversity of the microbial community increased and NBA-1 continued to be one of the dominant strains. Under aerobic conditions, the degradation rate of both nitrobenzene and p-CNB was only 20% of that under anaerobic conditions. p-CNB had a toxic effect on the microorganisms in the sludge so that most of the DGGE (denaturing gradient gel electrophoresis) bands, including that of NBA-1, began to disappear under aerobic conditions after 90days of exposure. These data show that the bacterial community was stable under anaerobic conditions and the microorganisms, including NBA-1, were more resistant to the adverse environment.
authors.affiliation: School of Environment and Energy, South China University of Technology, Higher Education Mega Center, Panyu District, Guangzhou 510006, PR China; The Key Laboratory of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, PR China; The Key Laboratory of Environmental Protection and Eco-Remediation of Guangdong Regular Higher Education Institutions, PR China. Electronic address: ceyren@scut.edu.cn.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Ren
authors.affiliation: School of Environment and Energy, South China University of Technology, Higher Education Mega Center, Panyu District, Guangzhou 510006, PR China.
authors.forename: Juan
authors.initials: J
authors.lastname: Yang
authors.affiliation: School of Environment and Energy, South China University of Technology, Higher Education Mega Center, Panyu District, Guangzhou 510006, PR China.
authors.forename: Shaoyi
authors.initials: S
authors.lastname: Chen
mesh_terms: D001673:Biodegradation, Environmental; D058645:Denaturing Gradient Gel Electrophoresis; D041121:Klebsiella oxytoca / Q000254:growth & development*; D009578:Nitrobenzenes / Q000032:analysis*; D012722:Sewage / Q000737:chemistry / Q000382:microbiology; D062065:Wastewater / Q000737:chemistry / Q000382:microbiology; D014874:Water Pollutants, Chemical / Q000032:analysis*; D018508:Water Purification / Q000379:methods*
chemical_list: D009578:Nitrobenzenes; D012722:Sewage; D062065:Wastewater; D014874:Water Pollutants, Chemical; C032785:2-chloronitrobenzene; C036077:nitrobenzene
keywords: Bacterial community; Fate; Nitrobenzene-degrading bacterium; PCR-DGGE; Pharmaceutical sludge