Quest for Nitrous Oxide-reducing Bacteria Present in an Anammox Biofilm Fed with Nitrous Oxide.

NO-reducing bacteria have been examined and harnessed to develop technologies that reduce the emission of NO, a greenhouse gas produced by biological nitrogen removal. Recent investigations using omics and physiological activity approaches have revealed the ecophysiologies of these bacteria during nitrogen removal. Nevertheless, their involvement in‍ ‍anammox processes remain unclear.

Complete genome sequence of strain SH125, a non-denitrifying nitrous oxide-reducing bacterium isolated from anammox biomass.

Here, we report a genome sequence of strain SH125 isolated from an anammox reactor. This facultative anaerobic strain possesses the clade I-type nitrous oxide (NO) reductase gene, devoid of nitrite- and nitric oxide reductase genes. Deciphering the genome will help explore NO reducers instrumental in NO mitigation.

Enhanced granulation of activated sludge in an airlift reactor for organic carbon removal and ammonia retention from industrial fermentation wastewater: A comparative study.

Ammonia retention and recovery from high-nitrogenous wastewater are new concepts being used for nitrogen management. A microaerophilic activated sludge system was developed to convert organic nitrogen into ammonia and retain it for its recovery; however, the settleability of activated sludge remains a challenge. Therefore, this study proposed an aerobic granular sludge system as a potential solution.

Organic carbon determines nitrous oxide consumption activity of clade I and II nosZ bacteria: Genomic and biokinetic insights.

Harnessing nitrous oxide (NO)-reducing bacteria is a promising strategy to reduce the NO footprint of engineered systems. Applying a preferred organic carbon source as an electron donor accelerates NO consumption by these bacteria. However, their NO consumption potential and activity when fed different organic carbon species remain unclear.

Combination of N Tracer and Microbial Analyses Discloses NO Sink Potential of the Anammox Community.

Although nitrogen removal by partial nitritation and anammox is more cost-effective than conventional nitrification and denitrification, one downside is the production and accumulation of nitrous oxide (NO). The potential exploitation of NO-reducing bacteria, which are resident members of anammox microbial communities, for NO mitigation would require more knowledge of their ecophysiology. This study investigated the phylogeny of resident NO-reducing bacteria in an anammox microbial community and quantified individually the processes of NO production and NO consumption.