Vectors for rapid selection of integrants with different plasmid copy numbers in the yeast Hansenula polymorpha DL1.

Plasmids with different selectable markers were constructed and used to transform the Hansenula polymorpha strain DL1. It was shown that, depending on the host mutant strain, the use of these plasmids enables rapid selection of transformants with plasmids integrated in low (1-2), moderate (6-9) or high (up to 100) copy numbers. The vectors and mutant described are potentially useful for the construction of efficient producers of heterologous proteins in H. polymorpha.