title: Degradation of textile dyes mediated by plant peroxidases.
abstract: The peroxidase enzyme from the plants Ipomea palmata (1.003 IU/g of leaf) and Saccharum spontaneum (3.6 IU/g of leaf) can be used as an alternative to the commercial source of horseradish and soybean peroxidase enzyme for the decolorization of textile dyes, mainly azo dyes. Eight textiles dyes currently used by the industry and seven other dyes were selected for decolorization studies at 25-200 mg/L levels using these plant enzymes. The enzymes were purified prior to use by ammonium sulfate precipitation, and ion exchange and gel permeation chromatographic techniques. Peroxidase of S. spontaneum leaf (specific activity of 0.23 IU/mg) could completely degrade Supranol Green and Procion Green HE-4BD (100%) dyes within 1 h, whereas Direct Blue, Procion Brilliant Blue H-7G and Chrysoidine were degraded >70% in 1 h. Peroxidase of Ipomea (I. palmata leaf; specific activity of 0.827 U/mg) degraded 50 mg/L of the dyes Methyl Orange (26%), Crystal Violet (36%), and Supranol Green (68%) in 2-4 h and Brilliant Green (54%), Direct Blue (15%), and Chrysoidine (44%) at the 25 mg/L level in 1 to 2 h of treatment. The Saccharum peroxidase was immobilized on a hydrophobic matrix. Four textile dyes, Procion Navy Blue HER, Procion Brilliant Blue H-7G, Procion Green HE-4BD, and Supranol Green, at an initial concentration of 50 mg/L were completely degraded within 8 h by the enzyme immobilized on the modified polyethylene matrix. The immobilized enzyme was used in a batch reactor for the degradation of Procion Green HE-4BD and the reusability was studied for 15 cycles, and the half-life was found to be 60 h.
authors.affiliation: Biochemical Processing Section, Regional Research Laboratory (CSIR), Thiruvananthapuram, India.
authors.forename: T S
authors.initials: TS
authors.lastname: Shaffiqu
authors.forename: J Jegan
authors.initials: JJ
authors.lastname: Roy
authors.forename: R Aswathi
authors.initials: RA
authors.lastname: Nair
authors.forename: T Emilia
authors.initials: TE
authors.lastname: Abraham
mesh_terms: D001391:Azo Compounds / Q000737:chemistry / Q000378:metabolism; D001673:Biodegradation, Environmental; D003116:Color; D004396:Coloring Agents / Q000378:metabolism*; D004800:Enzymes, Immobilized / Q000378:metabolism; D006735:Horseradish Peroxidase / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D027741:Ipomoea / Q000201:enzymology*; D010544:Peroxidases / Q000737:chemistry / Q000378:metabolism*; D010940:Plant Proteins / Q000737:chemistry / Q000378:metabolism*; D020959:Polyethylene / Q000737:chemistry; D031786:Saccharum / Q000201:enzymology*; D013784:Textiles
chemical_list: D001391:Azo Compounds; D004396:Coloring Agents; D004800:Enzymes, Immobilized; D010940:Plant Proteins; D020959:Polyethylene; D006735:Horseradish Peroxidase; D010544:Peroxidases