Premium
Degradation of Water‐Insoluble Dyes by Microperoxidase‐11, an Effective and Stable Peroxidative Catalyst in Hydrophilic Organic Media
Author(s) -
Wariishi Hiroyuki,
Kabuto Mari,
Mikuni Junko,
Oyadomari Masafumi,
Tanaka Hiroo
Publication year - 2002
Publication title -
biotechnology progress
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.572
H-Index - 129
eISSN - 1520-6033
pISSN - 8756-7938
DOI - 10.1021/bp010124v
Subject(s) - degradation (telecommunications) , catalysis , chemistry , chemical engineering , organic chemistry , computer science , telecommunications , engineering
Microperoxidase‐11 (MP‐11), a heme‐containing undecapeptide, derived from horse heart cytochrome c was utilized as a peroxidative catalyst. Catalytic characteristics of MP‐11 in hydrophilic organic media were studied using 2,6‐dimethoxyphenol as a reducing substrate in a series of organic solvents at various concentrations, indicating that MP‐11 was active in water‐miscible organic solvents but at least 5% water was compulsory for the catalytic action. Thus, MP‐11 was not active in hydrophobic solvents. The pH of the water portion in the media affected the reaction rate. The optimal pH was found to be 9, where a release of protons from either an oxidizing or reducing substrate to the media was facilitated. The decolorization of water‐insoluble synthetic dyes by MP‐11 in 90% methanol was attempted. MP‐11 showed effective decolorization activities against either azo or anthraquinone dyes. The degradation pathway for Solvent Orange 7 was investigated in detail, showing that MP‐11 catalyzed the oxidative cleavage of the azo linkage to generate 1,2‐naphthoquinone and 2,4‐dimethylphenol as key intermediates.