Characterization of a purified decolorizing detergent-stable peroxidase from Streptomyces griseosporeus SN9

A novel extracellular lignin peroxidase (called LiP-SN) was produced and purified from a newly isolated Streptomyces griseosporeus strain SN9. The findings revealed that the pure enzyme was a monomeric protein with an estimated molecular mass of 43 kDa and a Reinheitzahl value of 1.63. The 19 N-terminal residue sequence of LiP-SN showed high homology with those of Streptomyces peroxidases. Its optimum pH and temperature were pH 8.5 and 65 °C, respectively. The enzyme was inhibited by sodium azide and potassium cyanide, suggesting the presence of heme components in its tertiary structure. Its catalytic efficiency was higher than that of the peroxidase from Streptomyces albidoflavus strain TN644. Interestingly, LiP-SN showed marked dye-decolorization efficiency and stability toward denaturing, oxidizing, and bleaching agents, and compatibility with EcoVax and Dipex as laundry detergents for 48 h at 40 °C. These properties make LiP-SN a potential candidate for future applications in distaining synthetic dyes and detergent formulations.