Pichia Pastoris has become recognised as an attractive host option for the expression of recombinant genes at high levels. Its advantages includes growth to high cell density upon simple inexpensive media, the ability to introduce some eukaryotic post translational modifications and secretion of the product into the culture supernatant (and almost entirely free of contaminating proteins).
With Biomass levels of up to 500g/L wet weight being achieved in some laboratories, monitoring the concentration levels of viable Pichia Pastoris with the ABER Instruments has proven invaluable for fine tuning and controlling the nutrient feed rate. Cell growth profiles of the batch can be used to identify the key events or phases during the culture, such as the transition from fed-batch glycerol to continuous methanol feeding. As the Biomass Monitor is ideal for measuring high concentrations - and only measures the viable fraction - the instrument is able to detect any loss of culture viability when exposed to cytotoxic levels of methanol.
In laboratory tests it has been demonstrated that the ABER Instruments Biomass Monitor can improve productivity of protein production by 30%*. This particular result is achievable by indexing the glucose feed rate with the live cell mass (determined in pFcm) and subsequently maintaining a constant rate of delivery/ viable cell.