nitrification
Environmental MicrobiologyUse of Newly Designed Primers for Quantification of Complete Ammonia-Oxidizing (Comammox) Bacterial Clades and Strict Nitrite Oxidizers in the Genus NitrospiraNitrospira is a dominant nitrite-oxidizing bacterium in many artificial and natural environments. The discovery of complete ammonia oxidizers in the genus Nitrospira prevents the use of previously identified primers targeting the Nitrospira 16S rRNA gene or nitrite oxidoreductase (nxr) gene for differential determination of strict nitrite-oxidizing bacteria (sNOB) in the genus Nitrospira and...
Environmental MicrobiologySeasonal Dynamics of the Activated Sludge Microbiome in Sequencing Batch Reactors, Assessed Using 16S rRNA Transcript Amplicon SequencingSequencing batch reactors are a common design for wastewater treatment plants, particularly in smaller municipalities, due to their low footprint and ease of operations. However, like for most treatment plants in temperate/continental climates, the microbial community involved in water treatment is highly seasonal and its biological processes can be sensitive to cold temperatures. The seasonality of these microbial communities has been...
Environmental MicrobiologyGenomic Characteristics of a Novel Species of Ammonia-Oxidizing Archaea from the Jiulong River EstuaryIn this study, AOA communities along a river in southern China were characterized, and metagenome-assembled genomes (MAGs) of a novel AOA clade were also obtained. Based on the characterization of AOA genomes, the study suggests adaptation of the novel AOAs to estuarine environments, providing new information on the ecology of estuarine AOA and the nitrogen cycle in contaminated estuarine environments.
Environmental MicrobiologyLow Temperature and Neutral pH Define “Candidatus Nitrotoga sp.” as a Competitive Nitrite Oxidizer in Coculture with Nitrospira defluvii“Ca. Nitrotoga” is a NOB of high environmental relevance, but physiological data exist for only a few representatives. Initially, it was detected in specialized niches of low temperature and low nitrite concentrations, but later on, its ubiquitous distribution revealed its critical role for N removal in engineered systems like WWTPs. In this study, we analyzed the competition between Nitrotoga and Nitrospira...
Environmental Microbiology“Candidatus Nitrosotenuis aquarius,” an Ammonia-Oxidizing Archaeon from a Freshwater Aquarium BiofilterNitrification is a critical process for preventing ammonia toxicity in engineered biofilter environments. This work describes the cultivation and complete genome sequence of a novel AOA representative enriched from a freshwater aquarium biofilter. In addition, despite the common belief in the aquarium industry that AOB mediate ammonia oxidation, the present study suggests an in situ role for “Ca. Nitrosotenuis aquarius...
- Environmental MicrobiologyNitrosospira Cluster 8a Plays a Predominant Role in the Nitrification Process of a Subtropical Ultisol under Long-Term Inorganic and Organic Fertilization
The nitrification process is an important step in the nitrogen (N) cycle, affecting N availability and N losses to the wider environment. Ammonia oxidation, which is the first and rate-limiting step of nitrification, was widely accepted to be mainly regulated by AOA in acidic soils. However, in this study, nitrification activity was correlated with the abundance of AOB rather than that of AOA in acidic Ultisols....