Collagenolytic proteases are enzymes able of hydrolyzing the peptide bonds of several types of collagen, and have great importance in the medicine and therapeutic applications. The aim of this research was to evaluate the production of collagenolytic proteases by Bacillus stearothermophilus. Treatments were performed used a 2³ full factorial design, in order to evaluate the significance of the effects and interactions of variables - initial pH, substrate concentration and temperature - on the production of collagenolytic protease. The central point was run in quadruplicate to provide an estimate of the experimental error. Enzyme assays with collagen and azocasein as substrates were performed to determine the collagenolytic and proteolytic activities respectively. The highest collagenolytic enzyme activity was 79.38 U mL-1, corresponding to a specific activity of 136.86 U mg-1, in the initial fermentation conditions, substrate concentration at 1% (w/v), pH 7.2 and 25 °C. Proteolytic activity of enzyme was most active at pH 9.0 and 50 °C, and was stable over wide pH (6.0 - 9.0) and temperature ranges (45 °C - 50 °C). Bacillus stearothermophilus shows viability for the production of collagenolytic proteases, and the obtaining these enzymes have high importance for biotechnological applications.
bacterial enzymes; collagen; factorial design
