Abstract

SANCHEZ-ROSARIO, Yasmin; SANCHEZ, José E.; VAZQUEZ-DUHALT, Rafael  and  ANDRADE-GALLEGOS, René H.. Production and characterization of phenol oxidase produced by Scytalidium thermophilum. Rev. Mex. Mic [online]. 2011, vol.34, pp.31-42. ISSN 0187-3180.

In this work, the production of phenol oxidase from three strains of Scytalidium thermophilum was studied and the enzyme from the best producing strain was characterized. The enzyme production in three different culture media: Starch (SM), Potato Dextrose Yeast (PDY), and Grass Infusion (GI) at different temperatures (42, 45 and 48 °C) and different pH (6, 7 and 8) was evaluated. The highest enzymatic activity (0.115U/ml) was observed with the ECS-0602 strain in a Pangola grass infusion at pH 8 and 45 °C. Subsequently the purification of the enzyme by ionic exchange chromatography was carried out and the purified enzyme was characterized. The enzyme showed a molecular weight of 87 kDa in 10% SDS-PAGE gel and showed the highest activity at pH 7 and 55 °C. The -1 -1 maximal rate (V_max) was 80.72 μmoles min^-1mg of protein^-1 and the catalytic affinity constant max (K_M) was 302.79 mM, both determined with catechol as a substrate. The partially purified enzyme also showed catalase activity from pH 5.5 to 8 and at room temperature, with a maximal catalase activity of 10 640 Umg^-1 of protein at pH 6. The enzyme is a glycosilated hemoprotein that contains 0.7 moles of Fe per mol of protein.

Keywords : thermophilic fungi; catalase; extracellular enzyme; phenolic compounds; oxidase.