Modified protocol for quick and large-scale transformation of Pichia pastoris

Abstract

Over the last couple of decades, methylotrophic yeast, Pichia pastoris emerges as an important yeast species owing to its increasing application in industry and basic biological research. Transformation of Pichia pastoris cells for the introduction of the gene of interest is common practice for expression and purification of a heterologous protein(s). Presently available protocol of Pichia pastoris transformation involves preparation of competent cells and followed by their transformation. Preparation of competent cells requires growth of cells to certain cell density which requires lots of resource, space, time and efforts. This limits the number of transformations that can be performed by an individual at a time. In the present paper, I will describe a modification in the available protocol which makes P. pastoris transformation hassle free. The present procedure does not require growth of pre-culture or growth of cells to certain cell density rather cells are grown in a patch on YPD plate(s) and rest procedure is performed in small eppendrof tubes which allow a large number of transformations in quickest possible time with minimal resource and efforts. In the end, I also compare various protocols in tabular form which allows the user to choose best suitable procedure depending on the available resource, time, number of transformations, requirement, and efforts. The present modified protocol does not require big centrifuge and shaker which further makes this procedure more useful. I believe that present protocol of transformation with its many unique features will be really helpful to those working with P. pastoris.