Premium
Redox‐mediated decolorization of Direct Red 23 and Direct Blue 80 catalyzed by bioaffinity‐based immobilized tomato (Lycopersicon esculentum) peroxidase
Author(s) -
Matto Mahreen,
Husain Qayyum
Publication year - 2008
Publication title -
biotechnology journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.144
H-Index - 84
eISSN - 1860-7314
pISSN - 1860-6768
DOI - 10.1002/biot.200800049
Subject(s) - peroxidase , chemistry , redox , enzyme , lycopersicon , immobilized enzyme , cellulose , nuclear chemistry , chromatography , biochemistry , organic chemistry , botany , biology
The aim of this study was to investigate the role of concanavalin A (Con A)‐cellulose‐bound tomato peroxidase for the decolorization of direct dyes. Cellulose was used as an inexpensive material for the preparation of bioaffinity support. Con A‐cellulose‐bound tomato peroxidase exhibited higher efficiency in terms of dye decolorization as compared to soluble enzyme under various experimental conditions. Both Direct Red 23 and Direct Blue 80 dyes were recalcitrant to the action of enzyme without a redox mediator. Six compounds were investigated for redox‐mediating property. Immobilized peroxidase decolorized both dyes to different extent in the presence of all the used redox mediators. However, 1‐hydroxybenzotriazole emerged as a potential redox mediator for tomato peroxidase catalyzed decolorization of direct dyes. These dyes were maximally decolorized at pH 6.0 and 40°C by soluble and immobilized peroxidase. The absorption spectra of the untreated and treated dyes exhibited a marked difference in the absorption at various wavelengths. Immobilized tomato peroxidase showed a lower Michaelis constant than the free enzyme for both dyes. Soluble and immobilized tomato peroxidase exhibited significantly higher affinity for Direct Red 23 compared to Direct Blue 80.