Highly-efficient electrotransformation of the yeast Hansenula polymorpha

Klaas Nico Faber, Peter Haima, Wim Harder, Marten Veenhuis, Geert AB

OnderzoeksoutputAcademicpeer review

218 Citaten (Scopus)
745 Downloads (Pure)


A highly-efficient method for transformation of the methylotrophic yeast Hansenula polymorpha has been developed. Routinely, transformation frequencies of up to 1.7 x 10(6)/mu g plasmid DNA were obtained by applying an electric pulse of the exponential decay type of 7.5 kV/cm to a highly-concentrated cell mixture during 5 ms. Efficient transformation was dependent on: (1) pretreatment of the cells with the reducing agent dithiotreitol, (2) the use of sucrose as an osmotic stabilizer in an ionic electroporation buffer, and (3) the use of cells grown to the mid-logarithmic phase. Important parameters for optimizing the transformation frequencies were field strength, pulse duration, and cell concentration during the electric pulse. In contrast to electrotransformation protocols described for Saccharomyces cerevisiae and Candida maltosa, transformation frequencies (transformants per mu g DNA) for H. polymorpha remained high when large amounts (up to 10 mu g) of plasmid DNA were added. This feature renders this procedure pre-eminently advantageous for gene cloning experiments when high numbers of transformants are needed.

Originele taal-2English
Pagina's (van-tot)305-310
Aantal pagina's6
TijdschriftCurrent Genetics
Nummer van het tijdschrift4
StatusPublished - apr.-1994

Citeer dit