Changes in physiological characteristics of unstable recombinant strains of Hansenula polymorpha during chemostat cultivation

摘要

Unstable recombinant strains of Hansenula polymorpha leu 2-356 pL2 and H. polymorpha leu 2-356 4d-16 pR22-2 carrying (respectively) the vector plasmid pL2 with the marker gene leu2 and the hybrid plasmid with leu2 and dak (dioxyacetone kinase) genes were cultivated in a chemostat on a minimal medium containing methanol (without leucine). Initial populations containing growing and nongrowing plasmidfree cells displayed low biomass yields (in relation to substrate). Stabilities of both strains and the biomass yield (in relation to substrate) were shown to increase during chemostat growth.