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Abstract

ABSTRACT:The effect of pyoverdin I, a natural product from a Thai Pseudomonas aeruginosa strain, on the solubilization of iron and copper in two different artificially contaminated soils was investigated. The mobilized concentrations of both metals in the samples were determined by atomic absorption spectrometry. From these results, the presence of pyoverdin I can significantly increase the amount of extractable iron and copper compared to the control. The adsorption and desorption of these metals depend not only on the environmental pH but also on the soil type, which results from differences in the quantity of the organic matter. The ability of pyoverdin I to mobilize either metal in the soils indicates its important role in connection with toxicology, as well as for soil extraction and weathering. Studying the mobilization of metals by the bacterial pyoverdin I as a function of pH may provide additional information on the chemical association of metals in soil.

Contrasting effects of siderophores pyoverdine and desferrioxamine B on the mobility of iron, aluminum, and copper in Cu-contaminated soils

“…1c) in the CaCl2 extract was on average the same in DFOB-treated and in control soils, in 12 of the 14 Cu-contaminated soils tested in the present study. In this respect, DFOB contrasts with Pvd, which has been shown to bind and mobilize Cu in series of Cu-contaminated soils (Tansupo et al, 2008;Cornu et al, 2019) (see sections 3.2 and 3.3 for more details on this comparison). The targeted effect of DFOB on Fe and Al is in agreement with the results of previous studies that investigated the effect of DFOB on the mobility of metals in soil (Neubauer et al, 2000;Zhong et al, 2013;Cornu et al, 2017).…”

Determination activities of optimal conditions of peroxidase in hot Pepper and Broccoli

“…The supernatant was filtered through Whatman No.41 filter paper and collected as an enzyme extract. All the steps of enzyme extraction were carried out at 4°C (14,15 ). Fresh broccoli (Brassica oleracea var.)…”

“…Since peroxidase activity assay using guaiacol as a substrate is very sensitive and rapid, it is important to use the right levels of enzymatic activity in the extract, The enzyme source a reagent blank was prepared with 0.03 ml deionized water instead of antioxidant (control sample). One unit of activity is defined as a change in absorbance of 0.001 min-1 (14).…”

“…The solution of the reaction mixture contained 0.1 mL of 900 mM H 2 O 2 ,2.78 mL of 0.1 M phosphate buffer pH 7.0 and 0.1 mL of 16. 3mM guaiacol (14).…”

“…POD activity was performed using the different concentrations of substrate (10 ,12 ,14, 16 ,18) mM , and activity was assayed by using the mixture containing 40 µL of the extract of enzyme, 0.1 mL of 900 mM H 2 O 2 , 0.1 M phosphate buffer pH 7.0 and 16 .3 m M guaiacol at a selected volume. The effect of H 2 O 2 concentration on POD activity was studied using( 100 , 300 , 500 ,700 ,900, 100) m M the reaction system consisted of 40 µL of the enzyme extract, 0.15 mL of 16.3 m M guaiacol, 900 mM H 2 O 2 and 0.1M phosphate pH 7.0 at a selected volume, In each measurement, the final volume of the reaction solution was 3 mL in a quartz cuvette (14 ).…”