How stable are strains containing an integrated pKLAC1 expression construct?
The stability of pKLAC1-integrated strains depends on the nature of the protein being expressed and secreted. For example, in a population of cells expressing a protein that is toxic to K. lactis a certain percentage of cells may revert to wild-type by losing the integrated expression vector. The extent of reversion depends largely on the competitive growth advantage the wild-type strain has over the strain expressing the toxic protein. In our experience, K. lactis strains expressing proteins that do not adversely affect the health of cells can be grown continuously for >30 generations in non-selective medium with less than 5% reversion, as determined by Southern analysis.
