BI-VARIATE GROWTH MODEL OF PICHIA PASTORIS INCLUDING OXYGEN CONSIDERATIONS AND ITS IMPORTANCE IN RECOMBINANT PROTEIN PRODUCTION
The methylotrophic yeast, Pichia pastoris (recently reclassified as spp. Komagatella) has long been regarded as a useful host organism for the production of recombinant proteins, particularly when using the AOX system which utilizes methanol as both the inducing agent as well as the primary carbon source for growth and energy. Significant historical work has shown that growth rate and protein productivity can be correlated to methanol concentration. However, the relationship between oxygen and protein productivity are less consistent. While with many variations models having been developed and used for analyzing culture kinetics, these models have only been applied to methanol concentration. Furthermore, while results for methanol are fairly consistent, oxygen considerations have been far less consistent.
This work presents various bi-variate models which includes considerations for growth and inhibition for both methanol and oxygen with this expanded model showing strong alignment to previous works to both oxygen and methanol data. While more work is necessary to fully confirm and validate which form of the bivariate model is most appropriate, this work provides a framework necessary to expand analysis to include oxygen considerations. This framework has the potential to be used to further inform selection of feeding methodology as well as direct investigations into metabolic studies.