Oxygen isotope fractionation during anaerobic ammonium oxidation by the marine representative Candidatus Scalindua sp.

Analysing the nitrogen (15ε) and oxygen (18ε) isotope effects of anaerobic ammonium oxidation (anammox) is essential for accurately assessing its potential contribution to fixed-N losses in the ocean, yet the 18ε of anammox remains unexplored. Here, we determined the previously unexplored 18ε of anammox using a highly enriched culture of the marine anammox species "Ca. Scalindua sp".

Microbial Community Structure of Mesophilic and Low-temperature Partial Nitrification-anammox Reactors: Distribution and Functional Roles of the Core Microbiome.

Microbial community structures in mesophilic and low-temperature anammox and partial nitrification-anammox reactors were exami-ned by a 16S rRNA-gene amplicon sequencing ana-lysis. The anammox bacterium, Jettenia sp., was dominant, and nitrifying bacteria, including Nitrosomonas sp.

Interspecific competition and adaptation of anammox bacteria at different salinities: Experimental validation of the Monod growth model with salinity inhibition.

Ecological niche segregation of anaerobic ammonium oxidizing (anammox) bacteria under saline environments remains unresolved despite its ecological and practical importance. In this study, niche segregation by salinity for Ca. Brocadia sinica, Ca.

Salinity Tolerance and Osmoadaptation Strategies in Four Genera of Anammox Bacteria: , , , and .

The salinity tolerance and osmoadaptation strategies in four phylogenetically distant anammox species, , , , and , were investigated by using highly enriched cell cultures. The first-emerged ". Scalindua sp.

Collaborative metabolisms of urea and cyanate degradation in marine anammox bacterial culture.

Anammox process greatly contributes to nitrogen loss occurring in oceanic oxygen minimum zones (OMZs), where the availability of NH is scarce as compared with NO. Remineralization of organic nitrogen compounds including urea and cyanate (OCN) into NH has been believed as an NH source of the anammox process in oxygen minimum zones. However, urea- or OCN- dependent anammox has not been well examined due to the lack of marine anammox bacterial culture.

Growth of the Nitrosomonas europaea cells in the biofilm and planktonic growth mode: Responses of extracellular polymeric substances production and transcriptome.

Nitrosomonas europaea, an aerobic ammonia oxidizing bacterium, is responsible for the first and rate-limiting step of the nitrification process, and their ammonia oxidation activities are critical for the biogeochemical cycling and the biological nitrogen removal of wastewater treatment. In the present study, N. europaea cells were cultivated in the inorganic or organic media (the NBRC829 and the nutrient-rich, NR, media, respectively), and the cells proliferated in the form of planktonic and biofilm in those media, respectively.

Oxygen tolerance and detoxification mechanisms of highly enriched planktonic anaerobic ammonium-oxidizing (anammox) bacteria.

Oxygen is a key regulatory factor of anaerobic ammonium oxidation (anammox). Although the inhibitory effect of oxygen is evident, a wide range of oxygen sensitivities of anammox bacteria have been reported so far, which makes it difficult to model the marine nitrogen loss and design anammox-based technologies. Here, oxygen tolerance and detoxification mechanisms of four genera of anammox bacteria; one marine species ("Ca.

Metagenomic Analysis of Five Phylogenetically Distant Anammox Bacterial Enrichment Cultures.

Anaerobic ammonium-oxidizing (anammox) bacteria are slow-growing and fastidious bacteria, and limited numbers of enrichment cultures have been established. A metagenomic ana-lysis of our 5 established anammox bacterial enrichment cultures was performed in the present study. Fourteen high-quality metagenome-assembled genomes (MAGs) were obtained, including those of 5 anammox Planctomycetota (Candidatus Brocadia, Ca.

Growth of nitrite-oxidizing Nitrospira and ammonia-oxidizing Nitrosomonas in marine recirculating trickling biofilter reactors.

Aerobic ammonia and nitrite oxidation reactions are fundamental biogeochemical reactions contributing to the global nitrogen cycle. Although aerobic nitrite oxidation yields 4.8-folds less Gibbs free energy (∆G ) than aerobic ammonia oxidation in the NH -feeding marine recirculating trickling biofilter reactors operated in the present study, nitrite-oxidizing and not ammonia-oxidizing Nitrospira (sublineage IV) outnumbered ammonia-oxidizing Nitrosomonas (relative abundance; 53.

NO Reduction by Gemmatimonas aurantiaca and Potential Involvement of Gemmatimonadetes Bacteria in NO Reduction in Agricultural Soils.

Agricultural soil is the primary NO sink limiting the emission of NO gas into the atmosphere. Although Gemmatimonadetes bacteria are abundant in agricultural soils, limited information is currently available on NO reduction by Gemmatimonadetes bacteria. Therefore, the effects of pH and temperature on NO reduction activities and affinity constants for NO reduction were examined by performing batch experiments using an isolate of Gemmatimonadetes bacteria, Gemmatimonas aurantiaca (NBRC100505).

NHOH Disproportionation Mediated by Anaerobic Ammonium-oxidizing (Anammox) Bacteria.

Anammox bacteria produce N gas by oxidizing NH with NO, and hydroxylamine (NHOH) is a potential intermediate of the anammox process. N gas production occurs when anammox bacteria are incubated with NHOH only, indicating their capacity for NHOH disproportionation with NHOH serving as both the electron donor and acceptor. Limited information is currently available on NHOH disproportionation by anammox bacteria; therefore, the stoichiometry of anammox bacterial NHOH disproportionation was examined in the present study using N-tracing techniques.

Determination of N/N of Ammonium, Nitrite, Nitrate, Hydroxylamine, and Hydrazine Using Colorimetric Reagents and Matrix-Assisted Laser Desorption Ionization-Time-of-Flight Mass Spectrometry (MALDI-TOF MS).

In the nitrogen (N) cycle, nitrogenous compounds are chemically and biologically converted to various aqueous and gaseous N species. The N-labeling approach is a powerful culture-dependent technique to obtain insights into the complex nitrogen transformation reactions that occur in cultures. In the N-labeling approach, the fates of supplemented N- and/or unlabeled gaseous and aqueous compounds are tracked by mass spectrometry (MS) analysis, whereas MS analysis of aqueous N species requires laborious sample preparation steps and is performed using isotope-ratio mass spectrometry, which requires an expensive mass spectrometer.

Endpoint Recombinase Polymerase Amplification (RPA) Assay for Enumeration of Thiocyanate-degrading Bacteria.

An endpoint recombination amplification reaction (RPA) assay for assessing the abundance of the gene encoding thiocyanate dehydrogenase (TcDH) in Thiohalobacter has been developed. The RPA reaction was performed at 37°C for 30‍ ‍min, terminated by the addition of sodium dodecyl sulfate (SDS) solution, and the DNA concentration of the RPA product was fluorometrically measured. The abundance of TcDH in 22 activated sludge samples and 7 thiocyanate-degrading enrichment cultures ranged between 2.

Full-scale application of a down-flow hanging sponge reactor combined with a primary sedimentation basin for domestic sewage treatment.

The down-flow hanging sponge (DHS) reactor is advantageous for sewage treatment since it produces an effluent quality that complies with the standards for reuse and there is little excess sludge. A full-scale DHS module was efficiently employed for the treatment of domestic sewage (200 m day) flowing from a primary sedimentation basin (PSB), which was used to reduce the suspended solids loading rate and enhance the oxidation of organics by heterotrophs. The combined PSB-DHS was successfully operated at a total hydraulic retention time of 3.

Complete Genome Sequence of sp. Strain COW1, Isolated from Activated Sludge Treating Coke Oven Wastewater.

A thiocyanate-degrading bacterium, sp. strain COW1, was isolated from activated sludge treating coke oven wastewater, and the complete genome sequence was determined. COW1 contained a single circular chromosome (3.

Draft Genome Sequence of sp. Strain WSM2-2, Isolated from Garden Soil.

We report the draft genome sequence of sp. strain WSM2-2, isolated from garden soil. A 5.

Draft Genome Sequence of sp. AS-1, a Potential Eurytrophic Recombination Host.

Strain AS-1 was isolated from laboratory-scale activated sludge collected in Japan. This strain not only grows on rich medium, including R2A medium, but also forms colonies on medium lacking organic matter other than agar (water agar), indicating it could be used as a eurytrophic recombinant host in material production processes. Here, we present a draft genome sequence of sp.

Glycogen metabolism of the anammox bacterium "Candidatus Brocadia sinica".

Presence of glycogen granules in anaerobic ammonium-oxidizing (anammox) bacteria has been reported so far. However, very little is known about their glycogen metabolism and the exact roles. Here, we studied the glycogen metabolism in "Ca.

Cell Density-dependent Anammox Activity of Candidatus Brocadia sinica Regulated by N-acyl Homoserine Lactone-mediated Quorum Sensing.

The activity of anaerobic ammonia-oxidizing (anammox) bacteria is considered to depend on cell density; however, this has not yet been confirmed due to the fastidious nature of anammox bacteria (e.g., slow growth, oxygen sensitivity, and rigid aggregate formation).

Food selectivity of anaerobic protists and direct evidence for methane production using carbon from prey bacteria by endosymbiotic methanogen.

Anaerobic protists are major predators of prokaryotes in anaerobic ecosystems. However, little is known about the predation behavior of anaerobic protists because almost none have been cultured. In particular, these characteristics of anaerobic protists in the phyla Metamonada and Cercozoa have not been reported previously.

Biosynthesis of hydrazine from ammonium and hydroxylamine using an anaerobic ammonium oxidizing bacterium.

Objectives: To synthesize hydrazine (NH) from ammonium and hydroxylamine (NHOH) using an anaerobic ammonium oxidation (anammox) bacterium, Candidatus Kuenenia stuttgartiensis.

Results: K. stuttgartiensis cells were anoxically cultivated with the addition of ammonium (2 mM) and NHOH (1-100 mM) at pH 6-10.

Draft genome sequence of sp KR-1, a potential strain for palladium-leaching.

Strain KR-1 was isolated from pond water collected in Japan. Because this strain was capable of adsorbing palladium particles in sterilized water, strain KR-1 will be a useful biocatalyst for palladium-leaching from metal waste. Here we present a draft genome sequence of sp.

Simple and reliable enumeration of Escherichia coli concentrations in wastewater samples by measuring β-d-glucuronidase (GUS) activities via a microplate reader.

Monitoring of Escherichia coli concentrations at wastewater treatment plants (WWTPs) is important to ensure process performance and protect public health. However, conventional E. coli enumeration methods are complicated and time- and labor-consuming.