Production and Potential Application of an Alkaline Serine Peptidase from Myceliophtora heterothallica for Biofilm Removal.

Peptidases belong to the hydrolase class (EC 3.4) and catalyze the hydrolysis of peptide bonds. These enzymes, particularly those of microbial origin, have significant commercial importance because of their ease of production and wide range of industrial applications. The expansion of this market justifies the search for new enzymes with different substrate specificities, increased thermostability, and reduced production costs. In this study, we investigated the production of peptidases by the thermophilic fungus Myceliophtora heterothallica F2.1.4, via submerged culture and functional biochemical characterization of the produced enzymes. Among the conditions assessed, the fungus exhibited the highest peptidase production after 48 h of growth in medium supplemented with 0.5% casein. Regarding the functional properties of the produced enzymes, higher caseinolytic activity was observed under alkaline pH (9.5-10.5) and a temperature range of 45-50 °C for the pure enzyme (molecular mass estimated at 31 kDa) and 50-55 °C for the fermentative extract. Peptidases from the fermentative extract and the pure enzyme retained more than 60% of their activities for 1 h at 50 °C and were stable over a wide pH range (5.5-10.5). The proteolytic activity was primarily suppressed by PMSF and copper (II) and positively modulated by cobalt, showing an increase of up to 58% at 15 mM of this ion. The fermentative extract from the culture was effective in removing Staphylococcus aureus and Candida albicans biofilms with dispersal rates of 25% and 35%, respectively.