Abstract
It has been known that natural source of origin peroxidases, such as rice hull peroxidase (RPO), horseradish peroxidase (HRP), soybean peroxidase (SPO), and Arthromyces ramosus peroxidase (ARP), might be alternative candidates for bleaching system. However, their characteristics have not fully investigated. The purpose of this work is to evaluate these peroxidases for the decoloration of Orange II with high concentration of H2O2. Consequently, RPO system showed high decoloration rate contents even at the high concentration of H2O2, 150 mM, comparing with other PODs. Furthermore, decoloration activity of this RPO was stable under the coexistence of H2O2 at 120 minutes. By assessing PODs oxidation states at the high concentration of H2O2, 75 mM, intermediates, namely Compound III and Compound IV, appeared to be formed in the RPO and HRP oxidation cycle, and inactivated the decoloration reaction. Interestingly, only RPO system could maintain decoloration rate contents after several reaction cycles. In conclusion, RPO might be effective to edge closer to practical use as washing enzyme.
