The influence of ammonium and urea on the components of the proton electrochemical potential (delta p) and de novo synthesis of ATP was studied with Bacillus pasteurii ATCC 11859. In washed cells grown at high urea concentrations, a delta p of -56 +/- 29 mV, consisting of a membrane potential (delta psi) of -228 +/- 19 mV and of a transmembrane pH gradient (delta pH) equivalent to 172 +/- 38 mV...

We show that an indophenol-based colorimetric method for acetaminophen (Clin Toxicol 15: 67-73, 1979) has less than maximal sensitivity because of (a) incomplete hydrolysis, related to suboptimal acid concentration; (b) suboptimal hydrolysis time; and (c) possible deterioration of the ammonium hydroxide reagent after 2.5 months. We have modified the method by optimizing duration of hydrolysis a...

The inhibitory function of Klebsiella pneumoniae NifL on NifA transcriptional activity in vitro is stimulated by ATP and ADP when NifL is synthesized under nitrogen sufficiency (NifL(NH4)). Further characterizations showed that NifL(NH4) binds and hydrolyzes ATP (2500 mU/mg). Analyzing fusions between MalE and different portions of NifL, we localized both the ATP binding site and ATP hydrolysis...

Nitrogen (N) in livestock food sources that does not end up in a product (e.g. milk or eggs) or that does not get incorporated in body tissue is excreted by the animal. Nitrogen in the urine is in the form of urea which can rapidly hydrolyse to form ammonium carbonate. The decomposition of ammonium carbonate frees up ammonium ions that can volatilise as gaseous ammonia (NH3). Hydrolysis of urea...

In this study, a low-ammonium enzyme-induced carbonate precipitation (LA-EICP) technique is proposed that utilizes the cation exchange capability of zeolite to remove ammonium, an environmentally harmful by-product urea hydrolysis. The LA-EICP process modified (EICP) suitable for soil stabilization, by mixing and resulting solution amounts calcium precipitated ammonium ions removed synthetic ca...

Ammonium sulfate precipitation of urinary 17-ketosteroid conjugates is a rapid, effective method for isolating and purifying them. Negligible quantities of pigment are produced during acid hydrolysis of solutions of the precipitated conjugates. Despite elimination of nonspecific chromogenic material, colorimetric determinations of Zimmerman chromogens with use of the Allen correction of absorba...

The synthesis of nanostructured anionic-surfactant-templated mesoporous silica (AMS) recently appeared as a new strategy for the formation of nanostructured silica based materials. This method is based on the use of anionic surfactants together with a co-structure-directing agent (CSDA), mostly a silylated ammonium precursor. The presence of this CSDA is necessary in order to create ionic inter...