Electroinduced extraction of β-galactosidase from Kluyveromyces lactis

A new methodology for the extraction of beta -galactosidase from the yeast Kluyveromyces lactis was obtained by electropulsation. The application of a series of electric pulses (2 ms duration, I Hz frequency, and 4-4.5 kV/cm field strength) to fresh cells suspended in deionized water, followed by incubation in PBS., led to a spontaneous slow release of enzyme at a yield of 75-80% without any further treatment. Most of the enzyme was extracted within 8 h after electropulsation. This release was dependent on the growth phase. The specific activity of beta -galactosidase in the supernatant of pulsed cells was higher by a factor of 1.5-1.7 in comparison with crude extract.