PREPARATION OF A HIGHLY PURIFIED ACID PROTEASE SOLUTION FROM AN ASPERGILLUS ORYZAE NATIVE SOLUTION

Introduction. Most of the currently available enzyme preparations on the market are derived from raw materials of plant or animal origin. The process of isolation of enzymes from these sources is laborious and requires significant material costs. The cheapest source of acid proteases and α-amylases are molds. Objective: to prepare a highly purified acid protease solution from a native solution of the mold. Material and methods. The investigation object was acid protease from a native solution of 55 strains of Aspergillus oryzae. The investigators performed the Anson assay for measuring proteolytic activity and the Lowry method for total protein analysis. Acid protease was precipitated using organic solvents (ethanol, acetone) at different concentrations and inorganic electrolytes (ammonium sulfate). Results. The component composition of the native solution that turned out to exhibit heterogeneity in protein was investigated. The molecular weight of acid protease from Aspergillus oryzae was found to be 41 kDa. The precipitation process was shown to be most effective when ammonium sulfate was used as a precipitating agent. When there was a change in the level of ammonium sulfate saturation in the native solution, protein fractionation was ascertained to occur. The experimental results showed that there was a 1.9-fold concentration in enzyme solution in terms of proteolytic activity. The specific activity of acid protease increased by 3 times.. Conclusion. The authors have proposed a flow chart for an effective method to isolate and purify acid protease from the native solution of 55 strains of Aspergillus oryzae.