All aerobic biological systems, including N(2)-fixing root nodules, are subject to O(2) toxicity that results from the formation of reactive intermediates such as H(2)O(2) and free radicals of O(2). H(2)O(2) may be removed from root nodules in a series of enzymic reactions involving ascorbate peroxidase, dehydroascorbate reductase, and glutathione reductase. We confirm here the presence of thes...

A gas diffusion sequential injection system for spectrophotometric determination of free chlorine is described. The detection is based in the colorimetric reaction between free chlorine and a low toxicity reagent o-dianisidine. A gas diffusion unit is used to isolate free chlorine from the sample in order to avoid possible interferences. This feature results from the conversion of free chlorine...

We have modified an ultramicro method for determining glucose with glucose oxidase-peroxidase-odianisidine. Capillary blood is diluted in isotonic NaF (17.6-17.8 g/liter), the cells are removed, and glucose is determined after a 20-mm incubation with enzyme-containing reagent. Increasing the enzyme concentration fourfold nullifies interference from ascorbic acid and hemolysis, while greatly dec...

Sensitivity, stability, and specificity of the color-producing reaction of hydrogen peroxide with bezidine, leuco-malachite green, or o-dianisidine were tested in numerous systems containing hemoglobin and other hemoproteins. Use of urea or low temperature (to minus 12 degrees C), or both, was highly beneficial, especially with leuco-malachite green, for which the color reaction was stable, aft...

During the course of horseradish peroxidase-mediated oxidation of either o-dianisidine or 2-2'-azino-di(3-ethyl-benzthiazoline-6-sulfonic acid) (ABTS), no O2 consumption took place. When isonicotinic acid hydrazide (isoniazid) (INH) was included in the reaction mixture, O2 was consumed in amounts linearly related to the INH concentration. Nicotinic acid hydrazide at equimolar concentrations ind...

We expressed cDNAs coding for manganese peroxidases (MnPs) from the basidiomycetes Ceriporiopsis subvermispora (MnP1) and Phanerochaete chrysosporium (H4) under control of the alpha-amylase promoter from Aspergillus oryzae in Aspergillus nidulans. The recombinant proteins (rMnP1 and rH4) were expressed at similar levels and had molecular masses, both before and after deglycosylation, that were ...

The room temperature ionic liquid (IL) 1-butyl-3-methylimidazolium bis-(trifluorometanesulfonyl)imide BMIm[NTf₂] was used as a novel medium for improvement of separation and quantization of 16 aromatic amines typically present as contaminants in consumer products and detected by HPLC coupled to an electrochemical detector. The aromatic amines, namely 4,4'-diaminodiphenylmethane, 4-chloroaniline...

Saccharomyces cerevisiae was obtained from palm wine and used for the extraction of peroxidase. Peroxidase isolated partially purified characterized. A twelve-day pilot study carried out which gave highest activity on day eight. The crude enzyme-specific –0.751 U/mg with 70% ammonium sulfate precipitation peroxidase achieved. precipitation, following gel filtration Sephadex G-100. Two peaks con...