In this work, Pseudomonas cepacia was used for fermentation in bioreactor Bioflo III at 150 rpm, at 30 °C to 96 hours. Fermentation was conducted at 150 rpm for 96 hours in 30 °C. We analyzed the enzyme activity under different conditions of temperature (20 to 50 °C) and pH (3.0 to 11.0). The optimum activity values obtained were 37 °C and 8.0, respectively. To evaluate thermal stability, the enzyme was incubated in temperatures of 40, 50 and 60 °C for 120 minutes. Preliminary experiments were carried out to verify the appropriate conditions that should be used after the enzyme partition. Some tests were performed to determine some optimal conditions of lipase, including temperature and pH and tests of thermal stability using temperatures of 40, 50, and 60 °C. Next, the characterization of aqueous two-phase systems (ATPS) with PEG molar weight of 1500, 4000, and 6000 and phosphate varying pH 6 to 8 was made. Stock solutions of PEG 1500, 4000 and 6000 (50% w/w) and phosphate (20% w/w KH2PO4/K2HPO4) were prepared at the appropriate pH. This study on the characterization of the ATPS can be used for posterior partition of lipase, as well as of biological products within this pH range.
Pseudomonas cepacia; lipase; purification
