<b>Production and partial characterization of proteases from <i>Mucor hiemalis</i> URM3773

Resumo

The current study evaluated the proteases production from 11 fungal species belonging to the genera Mucor, Rhizomucor and Absidia. The species were obtained from the Collection of Cultures URM at the Mycology Department-UFPE, Brazil. The best producing species was Mucor hiemalis URM 3773 (1.689 U mL^-1). Plackett-Burman design methodology was employed to select the most effective parameter for protease production out of 11 medium components, including: concentration of filtrate soybean, glucose, incubation period, yeast extract, tryptone, pH, aeration, rotation, NH₄Cl, MgSO₄ and K₂HPO₄. Filtrated soybean concentration was the significant variable over the response variable, which was the specific protease activity. The crude enzyme extract showed optimal activity in pH 7.5 and at 50ºC. The enzyme was stable within a wide pH range from 5.8 to 8.0, in the phosphate buffer 0.1M and in stable temperature variation of 40-70ºC, for 180 minutes. The ions FeSO₄, NaCl, MnCl₂, MgCl₂ and KCl stimulated the protease activity, whereas ZnCl₂ ion inhibited the activity in 2.27%. Iodoacetic acid at 1mM was the proteases inhibitor that presented greater action.The results indicate that the studied enzyme have great potential for industrial application.