title: Effect of penicillin on nitrite-oxidizing bacteria in activated sludge.
abstract: The effects of penicillin G on the number and activity of nitrite-oxidizing bacteria were investigated in laboratory-scale reactors and batch tests. At a concentration of 100 mg L(-1), addition of penicillin G for short periods did not significantly affect nitrite oxidation, while addition for more than 2 months suppressed nitrite oxidation. Fluorescence in situ hybridization with 16S ribosomal RNA-targeted probes revealed a slight decrease in the abundance of Nitrospira, while Nitrobacter was not affected by addition of penicillin G for more than 39 days. The resistance of nitrite-oxidizing bacteria to penicillin appeared to be positively affected by intermittent aeration only when accompanied by denitrification; otherwise, the aeration mode (continuous or intermittent aeration) did not significantly affect the abundance of Nitrobacter and Nitrospira.
authors.affiliation: School of Civil Engineering and Architecture, Wuhan University of Technology, Wuhan, People's Republic of China.
authors.forename: Shao-Hui
authors.initials: SH
authors.lastname: Zhang
authors.forename: Francis L
authors.initials: FL
authors.lastname: de los Reyes
mesh_terms: D019149:Bioreactors / Q000382:microbiology; D009566:Nitrates / Q000378:metabolism*; D058465:Nitrification / Q000187:drug effects; D009576:Nitrobacter / Q000187:drug effects* / Q000378:metabolism*; D010084:Oxidation-Reduction / Q000187:drug effects; D010400:Penicillin G / Q000494:pharmacology*; D012722:Sewage / Q000382:microbiology*; D013997:Time Factors; D014865:Waste Disposal, Fluid
chemical_list: D009566:Nitrates; D012722:Sewage; D010400:Penicillin G