Limits...
Biobleaching of industrial important dyes with peroxidase partially purified from garlic.

Osuji AC, Eze SO, Osayi EE, Chilaka FC - ScientificWorldJournal (2014)

Bottom Line: The Km and V max for H2O2 and o-dianisidine were 0.026 mM and 0.8 U/min, and 25 mM and 0.75 U/min, respectively.Peroxidase from garlic was effective in decolourizing Vat Yellow 2, Vat Orange 11, and Vat Black 27 better than Vat Green 9 dye.For all the parameters monitored, the decolourization was more effective at a pH range, temperature, H2O2 concentration, and enzyme concentration of 4.5-5.0, 50°C, 0.6 mM, and 0.20 U/mL, respectively.

View Article: PubMed Central - PubMed

Affiliation: Department of Biochemistry, University of Nigeria, Nsukka, Nigeria.

ABSTRACT
An acidic peroxidase was extracted from garlic (Allium sativum) and was partially purified threefold by ammonium sulphate precipitation, dialysis, and gel filtration chromatography using sephadex G-200. The specific activity of the enzyme increased from 4.89 U/mg after ammonium sulphate precipitation to 25.26 U/mg after gel filtration chromatography. The optimum temperature and pH of the enzyme were 50°C and 5.0, respectively. The Km and V max for H2O2 and o-dianisidine were 0.026 mM and 0.8 U/min, and 25 mM and 0.75 U/min, respectively. Peroxidase from garlic was effective in decolourizing Vat Yellow 2, Vat Orange 11, and Vat Black 27 better than Vat Green 9 dye. For all the parameters monitored, the decolourization was more effective at a pH range, temperature, H2O2 concentration, and enzyme concentration of 4.5-5.0, 50°C, 0.6 mM, and 0.20 U/mL, respectively. The observed properties of the enzyme together with its low cost of extraction (from local sources) show the potential of this enzyme for practical application in industrial wastewater treatment especially with hydrogen peroxide. These Vat dyes also exhibited potentials of acting as peroxidase inhibitors at alkaline pH range.

Show MeSH
Effect of different concentrations of H2O2 on dye decolourization with garlic peroxidase.
© Copyright Policy - open-access
Related In: Results  -  Collection


getmorefigures.php?uid=PMC4226186&req=5

fig11: Effect of different concentrations of H2O2 on dye decolourization with garlic peroxidase.

Mentions: Figure 11 shows the effect of different concentration of H2O2 on dye decolourization. Different concentrations of hydrogen peroxide from 0.2 to 1.2 mM were used. The dye was best decolourized at a concentration of 6 mM H2O2 with 87, 89, and 92% decolourization for Vat Yellow 2, Vat Orange 11, and Vat Black 27 dyes, respectively. On the contrary, the Vat Green 9 had its best decolourization of 48% at 2.2 mM concentration of hydrogen peroxide. This could be because of the complex structure of the Vat Green 9 dye which is synthesized based on the structure of violanthrones known for their complex structure, while Vat Yellow 2, Vat Orange 11, and Vat Black 27 are synthesized based on the anthraquinone carbazoles, known for their simple structure as reported by Aspland [30]. Husain [15] reported that at the concentration of hydrogen peroxide greater than 0.75 mM, peroxidase activity was inhibited by irreversibly oxidizing the enzyme ferriheme group, essential for peroxidase activity. In this study we observed a relative lower concentration of hydrogen peroxide. The result of this study is in agreement with that of Vasantha et al.[29] who reported a concentration of 0.6 mM H2O2 for various dyes treated. This result is also in agreement with the report of Vazquez-Duarte et al. [31] who reported that the concentration of hydrogen peroxide greater than 1.2 mM acted as inhibitor of peroxidase activity possibly by causing irreversible oxidation of the enzyme ferriheme group which is essential for its activity.


Biobleaching of industrial important dyes with peroxidase partially purified from garlic.

Osuji AC, Eze SO, Osayi EE, Chilaka FC - ScientificWorldJournal (2014)

Effect of different concentrations of H2O2 on dye decolourization with garlic peroxidase.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4226186&req=5

fig11: Effect of different concentrations of H2O2 on dye decolourization with garlic peroxidase.
Mentions: Figure 11 shows the effect of different concentration of H2O2 on dye decolourization. Different concentrations of hydrogen peroxide from 0.2 to 1.2 mM were used. The dye was best decolourized at a concentration of 6 mM H2O2 with 87, 89, and 92% decolourization for Vat Yellow 2, Vat Orange 11, and Vat Black 27 dyes, respectively. On the contrary, the Vat Green 9 had its best decolourization of 48% at 2.2 mM concentration of hydrogen peroxide. This could be because of the complex structure of the Vat Green 9 dye which is synthesized based on the structure of violanthrones known for their complex structure, while Vat Yellow 2, Vat Orange 11, and Vat Black 27 are synthesized based on the anthraquinone carbazoles, known for their simple structure as reported by Aspland [30]. Husain [15] reported that at the concentration of hydrogen peroxide greater than 0.75 mM, peroxidase activity was inhibited by irreversibly oxidizing the enzyme ferriheme group, essential for peroxidase activity. In this study we observed a relative lower concentration of hydrogen peroxide. The result of this study is in agreement with that of Vasantha et al.[29] who reported a concentration of 0.6 mM H2O2 for various dyes treated. This result is also in agreement with the report of Vazquez-Duarte et al. [31] who reported that the concentration of hydrogen peroxide greater than 1.2 mM acted as inhibitor of peroxidase activity possibly by causing irreversible oxidation of the enzyme ferriheme group which is essential for its activity.

Bottom Line: The Km and V max for H2O2 and o-dianisidine were 0.026 mM and 0.8 U/min, and 25 mM and 0.75 U/min, respectively.Peroxidase from garlic was effective in decolourizing Vat Yellow 2, Vat Orange 11, and Vat Black 27 better than Vat Green 9 dye.For all the parameters monitored, the decolourization was more effective at a pH range, temperature, H2O2 concentration, and enzyme concentration of 4.5-5.0, 50°C, 0.6 mM, and 0.20 U/mL, respectively.

View Article: PubMed Central - PubMed

Affiliation: Department of Biochemistry, University of Nigeria, Nsukka, Nigeria.

ABSTRACT
An acidic peroxidase was extracted from garlic (Allium sativum) and was partially purified threefold by ammonium sulphate precipitation, dialysis, and gel filtration chromatography using sephadex G-200. The specific activity of the enzyme increased from 4.89 U/mg after ammonium sulphate precipitation to 25.26 U/mg after gel filtration chromatography. The optimum temperature and pH of the enzyme were 50°C and 5.0, respectively. The Km and V max for H2O2 and o-dianisidine were 0.026 mM and 0.8 U/min, and 25 mM and 0.75 U/min, respectively. Peroxidase from garlic was effective in decolourizing Vat Yellow 2, Vat Orange 11, and Vat Black 27 better than Vat Green 9 dye. For all the parameters monitored, the decolourization was more effective at a pH range, temperature, H2O2 concentration, and enzyme concentration of 4.5-5.0, 50°C, 0.6 mM, and 0.20 U/mL, respectively. The observed properties of the enzyme together with its low cost of extraction (from local sources) show the potential of this enzyme for practical application in industrial wastewater treatment especially with hydrogen peroxide. These Vat dyes also exhibited potentials of acting as peroxidase inhibitors at alkaline pH range.

Show MeSH