The release of virus-like particles from recombinant Saccharomyces cerevisiae: effect of freezing and thawing on homogenization and bead milling.
Recombinant cells of Saccharomyces cerevisiae, expressing virus-like particles (Ty-VLPs), can be readily disrupted in a high pressure homogenizer and show identical disruption kinetics to the untransformed host strain. When the cells are freeze/thawed before disruption, they become about four times more resistant to homogenization. This effect increases with the number of freeze/thaw cycles, but is independent of the time the cells remain frozen. The freeze/thaw effect is observed with cells harvested during both the logarithmic and stationary phase of growth, and occurs with the untransformed host strain as well as the transformed one. Freeze/thawed cells are twice as resistant to disruption in the bead mill as fresh cells.
Milburn
P T
PT
The Advanced Centre for Biochemical Engineering, Department of Chemical and Biochemical Engineering, University College London, Torrington Place, London WC1E 7JE, United Kingdom.
Dunnill
P
P