Extractive fermentation for process integration of protease production by Kita UCP1279 and purification by PEG-Citrate Aqueous Two-Phase System.

The present study evaluated the influence of the variables polyethylene glycol (PEG) molar mass, pH, PEG concentration and sodium citrate concentration in the integrated production of the protease from Kita UCP1279 by extractive fermentation, obtaining as a response the partition coefficient (), activity yield () and concentration factor (). The enzyme preferably partitioned to the top phase and obtained in the system formed by variables M = 400 g mol, C = 20% (w w), and C = 20% (w w) and pH 6, in this condition were obtained  = 1.90 and  = 79.90%. The protease showed stability at a temperature of 60 °C for 180 min, with optimum temperature 40 °C and pH 8.0. For the ions and inhibitors effects, the protease activity increased when exposed to Fe, Ca and Zn and inhibited by EDTA, being classified as metalloprotease. The kinetic parameters (35.63 mg mL) and (1.205 mg mLmin) were also estimated. Thus, the protease showed desirable characteristics that enable future industrial applications, especially, for beer industry.