CHARACTERISTICS COMPARISON BETWEEN PLASMID-HARBORING AND CHROMOSOME-INTEGRATED RECOMBINANT SACCHAROMYCES-CEREVISIAE CULTURES

It is important to understand the differences in characteristics betwe en plasmid-harboring recombinant yeast and chromosome-integrated recom binant yeast for the design and optimization of bioprocess employing r ecombinant yeast. In the present study, heterologous glucoamylase gene was inserted into yeast. The glucoamylase activity per gene copy numb er of chromosome-integrated recombinant yeast MMY2SUCSTA-I-5 was 3 to 6 folds higher than that of plasmid-harboring recombinant yeast MMY2SU CSTA. And the genetic stability of chromosome-integrated recombinant y east (99%) was far better compared to plasmid-harboring recombinant ye ast (65%). Better genetic stability and glucoamylase activity per gene copy number of chromosome-integrated recombinant yeast can provide ad vantages in higher final expression level, especially in continuous cu lture, compared to the plasmid-harboring recombinant yeast. The optima l glucose concentration for maximum expression of glucoamylase in chro mosome-integrated recombinant yeast was lower than that in plasmid-har boring recombinant yeast.