title: Evaluation of textile dye degradation due to the combined action of enzyme horseradish peroxidase and hydrogen peroxide.
abstract: The kinetic parameters of the oxidant action of the combination of enzyme horseradish peroxidase (HRP) with hydrogen peroxide in the degradation of methylene blue dye were investigated. Twenty-one percent of color removal was obtained at pH 5.0 and temperature of 30 °C. Under these conditions, the kinetic parameters K m and V max of enzymatic reactions were determined for hydrogen peroxide in the absence of methylene blue dye (K m = 17.3 mM; V max = 1.97 mM/min) and in the presence of methylene blue dye (K m = 0.27 mM, V max = 0.29 μM/min). By means of analysis of phosphorescence, the presence of reactive oxygen species was detected in the form of singlet oxygen through the redox reaction between HRP and hydrogen peroxide. The existence of this reactive species is directly dependent on the concentration of hydrogen peroxide in the aqueous solution.
authors.affiliation: UFRJ/EQ, Av. Athos da Silveira Ramos, 149 Bloco E, Rio de Janeiro, 21941-909, Brazil, andrerpereir@yahoo.com.br.
authors.forename: A R
authors.initials: AR
authors.lastname: Pereira
authors.forename: R S
authors.initials: RS
authors.lastname: da Costa
authors.forename: L
authors.initials: L
authors.lastname: Yokoyama
authors.forename: E M
authors.initials: EM
authors.lastname: Alhadeff
authors.forename: L A C
authors.initials: LA
authors.lastname: Teixeira
mesh_terms: D004396:Coloring Agents / Q000737:chemistry*; D006735:Horseradish Peroxidase / Q000737:chemistry; D006861:Hydrogen Peroxide / Q000737:chemistry*; D008751:Methylene Blue / Q000737:chemistry; D013784:Textiles
chemical_list: D004396:Coloring Agents; D006861:Hydrogen Peroxide; D006735:Horseradish Peroxidase; D008751:Methylene Blue