Microdetermination of phosphate in water by gel-phase colorimetry with molybdenum blue

Yoshimura, Kazuhisa; Ishii, Masatoshi.; Tarutani, Toshikazu

doi:10.1021/ac00294a023

Cited by 41 publications

(15 citation statements)

References 19 publications

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“…This is why we proposed earlier that the reduction of molybdate to molybdenum blue in EC 48 proceeds first by the formation of phosphomolybdate before Fig. 6 Visible absorption spectra of molybdenum blue from molybdosilicate (a) modified and adapted from Glenn and Crane [24], molybdosulfate (b), taken from Hori et al [28], and phosphomolybdate (c) taken from Yoshimura et al [29] Fig. 7 Changes in pH (filled circle) of the media during the course of molybdenum blue production (open circle).…”

Section: The Effect Of Temperature On Molybdate Reductionmentioning

confidence: 92%

Hexavalent Molybdenum Reduction to Molybdenum Blue by S. Marcescens Strain Dr. Y6

Shukor

Habib

Rahman

et al. 2008

Appl Biochem Biotechnol

116

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A molybdate-reducing bacterium has been locally isolated. The bacterium reduces molybdate or Mo(6+) to molybdenum blue (molybdate oxidation states of between 5+ and 6+). Different carbon sources such as acetate, formate, glycerol, citric acid, lactose, fructose, glucose, mannitol, tartarate, maltose, sucrose, and starch were used at an initial concentration of 0.2% (w/v) in low phosphate media to study their effect on the molybdate reduction efficiency of bacterium. All of the carbon sources supported cellular growth, but only sucrose, maltose, glucose, and glycerol (in decreasing order) supported molybdate reduction after 24 h of incubation. Optimum concentration of sucrose for molybdate reduction is 1.0% (w/v) after 24 h of static incubation. Ammonium sulfate, ammonium chloride, valine, OH-proline, glutamic acid, and alanine (in the order of decreasing efficiency) supported molybdate reduction with ammonium sulfate giving the highest amount of molybdenum blue after 24 h of incubation at 0.3% (w/v). The optimum molybdate concentration that supports molybdate reduction is between 15 and 25 mM. Molybdate reduction is optimum at 35 degrees C. Phosphate at concentrations higher than 5 mM strongly inhibits molybdate reduction. The molybdenum blue produced from cellular reduction exhibits a unique absorption spectrum with a maximum peak at 865 nm and a shoulder at 700 nm. The isolate was tentatively identified as Serratia marcescens Strain Dr.Y6 based on carbon utilization profiles using Biolog GN plates and partial 16s rDNA molecular phylogeny.

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Section: The Effect Of Temperature On Molybdate Reductionmentioning

confidence: 92%

Hexavalent Molybdenum Reduction to Molybdenum Blue by S. Marcescens Strain Dr. Y6

Shukor

Habib

Rahman

et al. 2008

Appl Biochem Biotechnol

116

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“…Although a detail identification of the actual phosphomolybdate species needs to be carried out using nuclear magnetic resonance (n.m.r) and electron spin resonance (e.s.r. ), spectrophotometric characterization of the heteropolymolybdate species through analyzing the scanning spectroscopic profile is a less cumbersome and accepted method (Yoshimura et al, 1986). Although the maximum absorption wavelength for Mo-blue was 865 nm, measurement at 750 nm, even though was about 30% lower, was enough for routine monitoring of molybdenum blue production as the intensity obtained was much higher than cellular absorption at 600-620 nm .…”

Section: Molybdenum Absorbance Spectrummentioning

confidence: 99%

ISOLATION AND CHARACTERIZATION OF A MOLYBDENUM-REDUCING AND GLYPHOSATE-DEGRADING Klebsiella oxytoca STRAIN SAW-5 IN SOILS FROM SARAWAK

et al. 2016

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Bioremediation of pollutants including heavy metals and xenobiotics is an economic and environmentally friendly process. A novel molybdenum-reducing bacterium with the ability to utilize the pesticide glyphosate as a carbon source is reported. The characterization works were carried out utilizing bacterial resting cells in a microplate format. The bacterium reduces molybdate to Mo-blue optimally between pH 6.3 and 6.8 and at 34 o C. Glucose was the best electron donor for supporting molybdate reduction followed by lactose, maltose, melibiose, raffinose, d-mannitol, d-xylose, l-rhamnose, l-arabinose, dulcitol, myo-inositol and glycerol in descending order. Other requirements include a phosphate concentration at 5.0 mM and a molybdate concentration between 20 and 30 mM. The molybdenum blue exhibited an absorption spectrum resembling a reduced phosphomolybdate. Molybdenum reduction was inhibited by mercury, silver, cadmium and copper at 2 ppm by 45.5, 26.0, 18.5 and 16.3%, respectively. Biochemical analysis identified the bacterium as Klebsiella oxytoca strain Saw-5. To conclude, the capacity of this bacterium to reduce molybdenum into a less toxic form and to grow on glyphosate is novel and makes the bacterium an important instrument for bioremediation of these pollutants.

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“…molybdenum reduction should proceed via the intermediate phosphomolybdate (Shukor et al 2007). Another basis for the hypothesis was the confirmation of the presence of phosphomolybdate species through spectrophotometric analysis of the resultant absorption spectrum (Sims 1961;Yoshimura et al 1986;Hori et al 1988).…”

Section: Molybdenum Absorbance Spectrummentioning

confidence: 99%

ISOLATION AND CHARACTERIZATION OF A MOLYBDENUM-REDUCING AND PHENOLIC- AND CATECHOL-DEGRADING Enterobacter sp. STRAIN SAW-2

Sabullah

Rahman²,

Ahmad³

et al. 2017

BIOTROPIA

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Molybdenum is an emerging pollutant worldwide. The objective of this study is to isolate molybdenum-reducing bacterium with the ability to grow on phenolic compounds (phenol and catechol). The screening process was carried out on a microplate. The bacterium reduced molybdenum in the form of sodium molybdate to molybdenum blue (Mo-blue). The bacterium required a narrow pH range for optimal reduction of molybdenum, i.e. between pH 6.3 and o 6.8, with temperature between 34 and 37 C. Molybdate reduction to Mo-blue was best supported by glucose as the carbon source. However, both phenol and catechol could not support molybdate reduction. Other requirements for molybdate reduction included sodium molybdate concentrations between 15 and 30 mM, and phosphate concentration of 5.0 mM. The bacterium exhibited a Mo-blue absorption spectrum with a shoulder at 700 nm and a maximum peak near the infrared region at 865 nm. The Mo-reducing bacterium was partially identified as Enterobacter sp. strain Saw-2. The capability of this bacterium to grow on toxic phenolic compounds and to detoxify molybdenum made it a significant agent for bioremediation.

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Microdetermination of phosphate in water by gel-phase colorimetry with molybdenum blue

Cited by 41 publications

References 19 publications

Hexavalent Molybdenum Reduction to Molybdenum Blue by S. Marcescens Strain Dr. Y6

Hexavalent Molybdenum Reduction to Molybdenum Blue by S. Marcescens Strain Dr. Y6

ISOLATION AND CHARACTERIZATION OF A MOLYBDENUM-REDUCING AND GLYPHOSATE-DEGRADING Klebsiella oxytoca STRAIN SAW-5 IN SOILS FROM SARAWAK

ISOLATION AND CHARACTERIZATION OF A MOLYBDENUM-REDUCING AND PHENOLIC- AND CATECHOL-DEGRADING Enterobacter sp. STRAIN SAW-2

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