Manganese Peroxidase from Trichoderma harzianum and Increasing Its Efficiency for Phenol Removal from Wastewater

Abstract

Manganese peroxidase (MnP) was isolated and purified from T. harzianum. The free and immobilized enzyme was activated by thioglycolate and reduced glutathione (GSH). After treatment with thioglycolate, the Vmax values for the free, alginate-immobilized MnP (alginate-E) and chitosan-immobilized MnP (chitosan-E) were 24.9, 27.9 and 32.6 Umg-1 protein, respectively. While, the Km values were 0.06, 0.053 and 0.071 mM. The Vmax values for the three forms of MnP in presence of GSH were 25.6, 26.9 and 33.7 U mg-1protein, respectively but Km values were 0.077, 0.065 and 0.11 mM. Free and immobilized forms were inhibited by o-phenanthroline, α,α-dipyridyl and ethylene glycol tetraacetate (EGTA). IC50 values for the free, alginate-E and chitosan-E in presence of o-phenanthroline were 0.6, 0.94 and 1.7 mM. In case of α,α-dipyridyl the values were 0.63, 0.7 and 0.89 mM. However, with EGTA the values were 0.77, 0.9 and 1.4 mM, respectively. Free and immobilized MnP expressed potentiality to remove phenol with T0.5 of 4.2, 2.95 and 1.5 h for free, alginate-E and chitosan-E, respectively. Our study reports an effective method to increase the catalytic efficiency of MnP using thiols. In addition, immobilized MnP from Trichoderma harzianum can be used for biotechnological application in removal of phenol from wastewater.