Proteases from an Amazonian Mushroom Species: A Mycotechnological Alternative for the Production of Milk Coagulant

Edible mushrooms have been used as sustainable sources of proteases of industrial interest. The aim of this research was to investigate the influence of different culture media on mycelial growth and the potential of an Amazonian mushroom species, Auricularia fuscosuccinea DPUA 1624, in the biosynthesis of bovine milk coagulant enzymes. The species was cultivated on Sabouraud agar, malt, glucose, and peptone agar, malt extract agar, and glucose and peptone agar, supplemented with yeast extract for mycelial development. Enzyme biosynthesis was evaluated by submerged fermentation. Subsequently, the cultures were incubated at 28 °C for 8 days. Proteolytic and coagulant activities were determined using 1% azocasein solution and milk powder as substrates, respectively. In the results of radial growth speed of A. fuscosuccinea, the values were significant in the GYP and SAB + YE culture media. However, GYP agar favored the growth and mycelial vigor of A. fuscosuccinea; therefore, this medium was selected to obtain inoculum in the tests. In submerged fermentation, the MGYP medium favored the synthesis of proteases for A. fuscosuccinea and synthesized coagulant proteases in 100% of the media, in which significant activity was observed in SAB + YE. The significant production of coagulant proteases of A. fuscosuccinea was obtained under the following conditions: inoculum size 10%, 8 days of fermentation period, and 8 days of inoculum age. The results indicate that A. fuscosuccinea DPUA 1624 has potential for use in industrial manufacturing, especially in dairy products.