Aerobic denitrifiers isolated from an alternating activated sludge system

Abstract

One hundred and sixty‐nine bacterial strains were isolated from activated sludge from a waste water treatment basin operating under alternating aerobic/anaerobic conditions. Sixteen strains from a subsample of 23 nitrogen oxide reducers were true respiratory denitrifiers, and all denitrified under both anaerobic and aerobic conditions. REP‐PCR band analysis showed different patterns for all strains. One strain (strain 1) produced large amounts of N2O and was studied in detail. Nitrous oxide was the major end product of denitrification by this strain, and NO−2 was reduced more efficiently than NO−3. The aerobic denitrification was most pronounced with NO−2 as electron acceptor, and the reduction of NO−2 was not coupled to NH+4 oxidation.

Identification of the bacterial community involved in methane-dependent denitrification in activated sludge using DNA stable-isotope probing

“…Another possibility is that aerobic denitrification was conducted by certain species of bacteria capable of corespiring oxygen and nitrogen oxides and producing N 2 (Meiberg et al , 1980; Robertson & Kuenen, 1984; Patureau et al , 1994). In contrast to common denitrifiers, aerobic denitrifiers appear to have an ecological advantage in niches with frequent aerobic/anoxic shifts (Frette et al , 1997). Additionally, it has been suggested that some aerobic denitrifiers prefer one‐carbon sources such as methanol and formate (Zhao et al , 1999; Takaya et al , 2003).…”

Enrichment and characterization of a bacteria consortium capable of heterotrophic nitrification and aerobic denitrification at low temperature

“…This indicates that a consortium with excellent aerobic denitrification capability at low temperature was successfully obtained in R2.As shown previously, the aeration mode played an important role in the enrichment process. Alternating aerobic/anoxic conditions could lead to a high density of bacteria carrying out aerobic denitrification, as reported in several studies(Frette et al, 1997;Patureau et al, 2000). Moreover, sequential aerobic cultivation in the presence of…”

Molecular characterization of a microbial consortium involved in methane oxidation coupled to denitrification under micro‐aerobic conditions

“…From the enrichment culture and batch experiment, we infered that aerobic denitrification was conducted by certain species of bacteria that utilized O 2 , NO 2 − and/or NO 3 − simultaneously as electron acceptors. The existence and the growth of aerobic denitrifiers have been reported to occur in various environments (Frette et al ., ; Huang and Tseng, ). In our batch experiments, enriched sludge in the aerobic treatment exhibited about twice as much denitrification activity compared with that in micro‐aerobic treatment.…”