Production of milk coagulating proteases by amazonian edible mushroom of the Polyporaceae family (Basidiomycota)

Cheese is a dairy product that plays a fundamental role in the global economy. However, factors such as high rennet prices and religious and ethnic motivations against the use of animal-derived enzymes encourage the search for new coagulation agents. In this context, edible mushrooms have been emerging as promising sources of coagulant proteases for cheese production. The aim of this research was to evaluate the production of coagulant proteases and determine the parameters that influence the synthesis of these biocatalysts by Lentinus crinitus DPUA 1693. For enzyme production in liquid medium, the mushroom was cultivated in Potato Extract (PDA), Sabouraud Extract (SAB), Corn Meal (CMA), supplemented with yeast extract (YE) 0.5% (w/v) and Glucose, Yeast Extract, and Peptone (MGYP+YE). The proteolytic and coagulant activities were determined using 1% (w/v) azocasein solution and 10% (w/v) skimmed milk, respectively, as substrate. The parameters that interfere in the coagulant production were evaluated, such as inoculum size, fermentation time, and inoculum age. The protein profile of the crude extract and the zymogram to confirm the proteolytic action of the extract were determined by non-denaturing polyacrylamide gel electrophoresis (SDS-PAGE). The significant values of coagulant activity (18.21 U mL-1) in SAB and MGYP, as well as protease activity (1.64 U mL-1 and 1.66 U mL-1), respectively, with the ratio and strong clot. The significant coagulant production was verified under the following conditions: inoculum size (20%), fermentation time (10 days), and inoculum age (16 days). The significant values of activity and coagulant ratio, as well as the evidence of proteolytic action in zymograms, indicate the technological quality of the application of enzymes in the industrial sector. Lentinus crinitus DPUA 1693 is a natural source of coagulant with characteristics for the application of enzymes in the dairy sector.