Chinese Journal of Catalysis ›› 2016, Vol. 37 ›› Issue (4): 561-570.DOI: 10.1016/S1872-2067(15)61044-0

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Purification and characterization of manganese peroxidases from native and mutant Trametes versicolor IBL-04

Muhammad Asgher, Muhammad Ramzan, Muhammad Bilal   

  1. Industrial Biotechnology Laboratory, Department of Biochemistry, University of Agriculture, Faisalabad, Pakistan
  • Received:2015-11-08 Revised:2016-01-14 Online:2016-03-30 Published:2016-03-30
  • Contact: Muhammad Bilal

Abstract:

Extracellular manganese peroxidases (MnPs) produced by native and mutant strains of Trametes versicolor IBL-04 (EB-60, EMS-90) were purified by ammonium sulphate precipitation and dialysis, followed by ion-exchange and gel-permeation chromatography. The purified enzymes elucidated a single band in the 43-kDa region on sodium dodecyl sulphate-polyacrylamide gel electrophoresis. The optimum pH and temperature of the purified enzymes were found to be 5.0 and 40 ℃, respectively. Mutant strain MnPs exhibited a broader active pH range and higher thermal stability than native MnP. Purified MnPs from selected mutants showed almost identical properties to native MnP in electrophoresis, steady-state kinetics, and metal ion and endocrine-disrupting compound (EDC) degradation efficiency. Although the fastest reaction rates occurred with Mn2+, MnPs displayed the highest affinity for ABTS, methoxyhydroquinone, 4-aminophenol and reactive dyes. MnP activity was significantly enhanced by Mn2+ and Cu2+, and inhibited in the presence of Zn2+, Fe2+, ethylenediaminetetraacetic acid and cysteine to various extents, with Hg2+ as the most potent inhibitory agent. MnPs from all sources efficiently catalyzed the degradation of the EDCs, nonylphenol and triclosan, removing over 80% after 3 h of treatment, which was further increased up to 90% in the presence of MnP-mediator system. The properties of T. versicolor MnPs, such as high pH and thermal stability, as well as unique Michaelis-Menten kinetic parameters and high EDC elimination efficiency, render them promising candidates for industrial exploitation.

Key words: Manganese peroxidase, Trametes versicolor IBL-04, Purification, Characterization, Thermo-stability, Biodegradation