Synthesis and properties of lignin peroxidase from Streptomyces viridosporus T7A

The production of lignin peroxidase by Streptomyces viridosporus T7A was studied in shake flasks and under aerobic conditions in a 7.5-L batch fermentor. Lignin peroxidase synthesis was found to be strongly affected by catabolite repression. Lignin peroxidase was a non-growth-associated, secondary metabolite. The maximum lignin peroxidase activity was 0.064 U/mL at 36 h. In order to maximize lignin peroxidase activity, optimal conditions were determined. The optimal incubation temperature, pH, and substrate (2,4-dichlorophenol) concentration for the enzyme assays were 45 degrees C, 6, and 3 mM, respectively. Stability of lignin peroxidase was determined at 37, 45, and 60 degrees C, and over the pH range 4-9.