Nitrification is known as one of the most sensitive processes affected when activated sludge is exposed to antimicrobial silver nanoparticles (AgNPs). The impact of AgNPs and their released silver ions (Ag(+) ) on the abundance, activity, and diversity of different nitrifying bacteria in wastewater treatment plants (WWTPs), however, is poorly understood. The present study investigated the impac...

NiRs (nitrite reductases) convert nitrite into NO in the denitrification process. RpNiR (Ralstonia pickettii NiR), a new type of dissimilatory Cu-containing NiR with a C-terminal haem c domain from R. pickettii, has been cloned, overexpressed in Escherichia coli and purified to homogeneity. The enzyme has a subunit molecular mass of 50515 Da, consistent with sequence data showing homology to th...

Preliminary data on the kinetics of the oxidation of nitrite by Nitrobacter were presented by Laudelout & van Tichelen (1960). The present observations complete and extend the results concerning the effects of pH, concentrations of nitrite and of nitrate, temperature and oxygen partial pressure on the parameters of the rate equation for the oxidation of nitrite by intact cells and cell-free ext...

A simple, precise and accurate method is proposed for rapid determination of trace amounts of hydroxylamine based on the reaction of hydroxylamine with iodate in acidic media. The reaction of neutral red by the produced nitrite ion was used to monitor the reaction spectrophotometrically at 525 nm by a fixed time method. Hydroxylamine in the range of 0.0400-1.200 microg mL(-1) could be determine...

A fast and highly sensitive ion chromatographic method using monolithic ODS columns was developed for the determination of nitrite (NO2-) and nitrate (NO3-) in seawater. Two monolithic ODS columns (50 mm x 4.6 mm i.d. + 100 mm x 4.6 mm i.d.) connected in series were coated and equilibrated with 5 mM cetyltrimethylammonium chloride (CTAC) aqueous solution. The column efficiency with 0.5 M NaCl a...

nitrite is responsible for some characteristics of cured meat products such as color, flavor and suppressing the outgrowth and production of toxin from clostridium botulinum. despite all of its desired properties, nitrite is responsible for the formation of carcinogenic n-nitrosamine. in this study, nitrite-free and low-nitrite meat curing systems were developed to eliminate or reduce nitrite f...

A high-performance continuous-flow analyser is used for the analysis of nitrate, nitrite and ammonium ion in potable waters. The results demonstrate that (1) the analyser allows the sequential determination of a number of analytes without requiring modification to the manifold; (2) the use of programmed slicing of the reaction mixture allows a wide range of analyte concentrations to be handled;...

Coastal ecosystems play significant ecological and economic roles but are threatened and facing decline. Microbes drive various biogeochemical processes in coastal ecosystems. Tidal flats are critical components of coastal ecosystems; however, the structure and function of microbial communities in tidal flats are poorly understood. Here we investigated the seasonal variations of bacterial commu...