Improved cavitational cell disruption following pH pretreatment for the extraction of β-galactosidase from Kluveromyces lactis

The efficient release of intracellular beta-galactosidase by ultrasonic disruption of cells treated with aqueous solutions of different pH has been investigated to improve the cavitational efficacy of the cell disruption process. Pretreatment of the cells at different pHs for various time intervals was studied. The maximum yield (95 +/- 3 U/ml) was obtained by pretreatment of the cells at pH 4.4 for 6 h and subsequent ultrasonic cell disruption for 40 min. The maximum yield on ultrasonic disruption without pretreatment was 7.2 +/- 0.6 U/ml. The energy efficiency of the disruption process for releasing P-galactosidase using different pre-treatments has been calculated and compared. (c) 2006 Elsevier B.V. All rights reserved.