Resumo

Various thrombolytic agents have been used in the therapeutic treatment of thrombosis, but due to their high cost and hemorrhagic side effects, have been sought new sources. This study describes the production of fibrinolytic proteases by Mucor subtillissimus SIS 42 in solid-state fermentation (SSF) using soybean as substrate. The conditions for fibrinolytic proteases production activity were determined by full factorial design (2³). The influence of the parameters: substrate amount (3, 5 and 7g), moisture (30, 40 and 50%) and temperature (25, 30 and 35ºC) was evaluated. Extraction of the enzyme was performed using of sodium phosphate buffer 245mM (pH 7). The fibrinolytic activity was determined using the spectrophotometric method being performed with 72, 96 and 120 hours of fermentation. The fermentation condition which used 3g of soybean, 30% moisture at temperature 25°C proved the best conditions for the fibrinolytic protease production by Mucor subtillissimus. These conditions obtained an activity of 140.0 U/mL, 1878.35 U/gds after 72 hours of fermentation. All variables and interactions between them were significant (p<0.05), the temperature and substrate amount had a negative effect, as well as the interaction between them. However, moisture demonstrated a significant positive effect. The greater moisture tends to use higher enzyme production, possibly due to a rise of the substrate porosity, consequently a better oxygen transfer thereby favoring the development of microorganism. The literature show that most fungi have an optimum temperature of protease production by SSF between 28°C to 30°C, which differs from that shown in this study, where the M. subtillissimus SIS42 has its best enzyme production at 25°C using soybean as substrate. Optimization studies of fibrinolytic protease production by Mucor subtillissimus SIS42 may provide promising results in the future, for application in process sanguine fibrinolysis.